Oxford Handbook of Clinical Medicine 10th Ed PDF

‘He who studies medicine without books sails an unchartered sea, but he who studies medicine without patients does not go to sea at all’ William Osler 1849–1919 The word ‘patient’ occurs frequently throughout this book. Do not sk...

‘He who studies medicine without books sails an unchartered sea, but he who studies medicine without patients does not go to sea at all’ William Osler 1849–1919 The word ‘patient’ occurs frequently throughout this book. Do not skim over it lightly. Rather pause and doff your metaphorical cap, offering due respect to those who by the opening up of their lives to you, become your true teachers. Without your patients, you are a technician with a useless skill. With them, you are a doctor. He moved N. 48 all the brightest gems N. 24 faster and faster towards the N. 18 ever-growing bucket of lost hopes; N. 14 had there been just one more year of peace the battalion would have made N. 12 a floating system of perpetual drainage. A silent fall of immense snow came near oily N. 10 remains of the recently eaten supper on the table. We drove on in our old sunless walnut. Presently classical eggs ticked in the new afternoon shadows. N. 8 We were instructed by my cousin Jasper not to exercise by country house visiting unless accompanied by thirteen geese or gangsters. N. 6 The modern American did not prevail over the pair of redundant bronze puppies. The worn-out principle is a bad omen which I am never glad to ransom in August. N. 5 Reading tests Hold this chart (well-illuminated) 30cm away, and record the smallest type read (eg N12 left eye, N6 right eye, spectacles worn) or object named accurately. Common haematology values Haemoglobin men: 130–180g/L p324 women: 115–160g/L p324 Mean cell volume, MCV 76–96fL p326; p332 Platelets 150–400 ≈ 109/L p364 White cells (total) 4–11 ≈ 109/L p330 neutrophils 2.0–7.5 ≈ 109/L p330 lymphocytes 1.0–4.5 ≈ 109/L p330 eosinophils 0.04–0.4 ≈ 109/L p330 Blood gases pH 7.35–7.45 p670 PaO2 >10.6kPa p670 PaCO2 4.7–6kPa p670 Base excess ± 2mmol/L p670 U&E S (urea and electrolytes) Sodium 135–145mmol/L p672 Potassium 3.5–5.3mmol/L p674 Creatinine 70–100μmol/L p298–301 Urea 2.5–6.7mmol/L p298–301 eGFR >60 p669 LFTS (liver function tests) Bilirubin 3–17μmol/L p272, p274 Alanine aminotransferase, ALT 5–35IU/L p272, p274 Aspartate transaminase, AST 5–35IU/L p272, p274 Alkaline phosphatase, ALP 30–130IU/L p272, p274 (non-pregnant adults) Albumin 35–50g/L p686 Cardiac enzymes Troponin T 100bpm. See p127. Sinus bradycardia Sinus rhythm at a rate 0.12s, ‘M’ pattern in V5, dominant S in V1, inverted T waves in I, aVL, V5–V6. Causes: IHD, hypertension, cardiomyopathy, idi- opathic fibrosis. NB: if there is LBBB, no comment can be made on the ST segment or T wave. New LBBB may represent a STEMI, see p798. Bifascicular block: The combination of RBBB and left bundle hemiblock, manifest as an axis deviation, eg left axis deviation in the case of left anterior hemiblock. Trifascicular block: Bifascicular block plus 1st-degree HB. May need pacing (p132). Suspect left ventricular hypertrophy (LVH) if the R wave in V6 is >25mm or the sum of the S wave in V1 and the R wave in V6 is >35mm (see fig 3.41). Suspect right ventricular hypertrophy (RVH) if dominant R wave in V1, T wave inver- sion in V1–V3 or V4, deep S wave in V6, right axis deviation. Other causes of dominant R wave in V1: RBBB, posterior MI, type A WPW syndrome (p133). Causes of low-voltage QRS complex: (QRS 0.5) suggests congestive heart failure; signs of pulmo- nary oedema suggest decompensated heart failure (see fig 3.38); a globular heart may indicate pericardial effusion (fig 3.14); metal wires and valves will show up, evidencing previous cardiothoracic surgery; dextrocardia may explain a bizarre ECG; and rib notching may be an important clue in coarctation of the aorta (p156). Echocardiography This is the workhorse of cardiological imaging. Ultrasound is used to give real-time images of the moving heart. This can be transthoracic (TTE) or transoesophageal (TOE), at rest, during exercise, or after infusion of a pharmaco- logical stressor (eg dobutamine). If the patient is too unwell to be moved, an echo machine can be brought to them and continuous TOE imaging may be used as a guide during surgery. Increasingly pocket-sized echo machines are used for a quick assess- ment of an unwell patient, to be followed by a formal scan later. See p110. Cardiac CT This can provide detailed information about cardiac structure and func- tion. CT angiography (fig 3.15) permits contrast-enhanced imaging of coronary ar- teries during a single breath hold with very low radiation doses. It can diagnose significant (>50%) stenosis in coronary artery disease with an accuracy of 89%. CT coronary angiography has a negative predictive value of >99%, which makes it an effective non-invasive alternative to routine transcatheter coronary angiography to rule out coronary artery disease.6 Medications are often given to slow the heart down and the imaging may be ‘gated’, meaning the scanner is programmed to take images at times corresponding to certain points on the patient’s ECG. This allows characterization of the heart at different points in the cardiac cycle. See p740. Cardiac MR A radiation-free method of characterizing cardiac structure and func- tion including viability of myocardium. By varying the settings, different defects can be found. MR is the first-choice imaging method to look at diseases that directly af- fect the myocardium (fig 3.16). Nowadays, pacemakers are available which are safe for MR scanning—check MR safety with your cardiac technicians before requesting MR for patients with pacemakers in situ. See p740. Nuclear imaging Perfusion is assessed at rest and with exercise- or pharmacolog- ically-induced stress. This test is particularly useful for assessing whether myocar- dium distal to a blockage is viable and so whether stenting or CABG will be of value. If hypoperfusion is ‘fixed’, ie present at rest and under stress, the hypoperfused area is probably scar tissue and so non-viable. If hypoperfusion is ‘reversible’ at rest, the myocardium may benefit from improved blood supply. See p741.  109 Cardiovascular medicine Fig 3.14 Two chest X-rays of the same patient, the one on the right was taken 6 months after the one on the left. On the later image, a pericardial effusion has expanded the cardiac shadow and given it a ‘globular’ shape. Reproduced from Leeson, Cardiovascular Imaging, 2011, with permission from Oxford University Press. Fig 3.15 Cardiac CT demonstrating coronary artery Fig 3.16 Cardiac MR image demonstrat- stenosis. ing the asymmetrical left ventricular wall Reproduced from Camm et al., ESC Textbook of Cardio- thickening typical of hypertrophic cardio- vascular Medicine, 2009, with permission from Oxford myopathy. University Press. Reproduced from Myerson et al., Cardio- vascular Magnetic Resonance, 2013, with permission from Oxford University Press. 110 Echocardiography This non-invasive technique uses the differing ability of various structures within the heart to reflect ultrasound waves. It not only demonstrates anatomy but also provides a continuous display of the functioning heart throughout its cycle. Types of scan M-mode (motion mode): A single-dimension image. Cardiovascular medicine Two-dimensional (real time): A 2D, fan-shaped image of a segment of the heart is produced on the screen (fig 3.17); the moving image may be ‘frozen’. Several views are possible, including long axis, short axis, 4-chamber, and subcostal. 2D echocar- diography is good for visualizing conditions such as: congenital heart disease, LV aneurysm, mural thrombus, LA myxoma, septal defects. 3D echocardiography: Now possible with matrix array probes, and is termed 4D (3D + time) if the images are moving. Doppler and colour-flow echocardiography: Different coloured jets illustrate flow and gradients across valves and septal defects (p156) (Doppler effect, p736). Tissue Doppler imaging: This employs Doppler ultrasound to measure the velocity of myocardial segments over the cardiac cycle. It is particularly useful for assessing longitudinal motion—and hence long-axis ventricular function, which is a sensitive marker of systolic and diastolic heart failure. Transoesophageal echocardiography (TOE): More sensitive than transthoracic echo- cardiography (TTE) as the transducer is nearer to the heart. Indications: diagnosing aortic dissections; assessing prosthetic valves; finding cardiac source of emboli, and IE/SBE. Contraindicated in oesophageal disease and cervical spine instability. Stress echocardiography: Used to evaluate ventricular function, ejection fraction, myocardial thickening, regional wall motion pre- and post-exercise, and to charac- terize valvular lesions. Dobutamine or dipyridamole may be used if the patient can- not exercise. Inexpensive and as sensitive/specific as a thallium scan (p741). Uses of echocardiography Quantification of global LV function: Heart failure may be due to systolic or diastol- ic ventricular impairment (or both). Echo helps by measuring end-diastolic volume. If this is large, systolic dysfunction is the likely cause. If small, diastolic. Pure forms of diastolic dysfunction are rare. Differentiation is important because vasodilators are less useful in diastolic dysfunction as a high ventricular filling pressure is required. Echo is also useful for detecting focal and global hypokinesia, LV aneurysm, mural thrombus, and LVH (echo is 5–10 times more sensitive than ECG in detecting this). Estimating right heart haemodynamics: Doppler studies of pulmonary artery flow and tricuspid regurgitation allow evaluation of RV function and pressures. Valve disease: The technique of choice for measuring pressure gradients and valve orifice areas in stenotic lesions. Detecting valvular regurgitation and estimating its significance is less accurate. Evaluating function of prosthetic valves is another role. Congenital heart disease: Establishing the presence of lesions, and significance. Endocarditis: Vegetations may not be seen if 6h post-dose (p756). Typical dose: 500mcg stat PO, repeated after 12h, then 125mcg (if elderly) to Cardiovascular medicine 250mcg/d PO OD (62.5mcg/d is almost never enough). IV dose: 0.75–1mg in 0.9% NaCl over 2h. Toxicity risk if: K+, Mg2+, or Ca2+. t½ ≈ 36h. If on digoxin, use less energy in cardioversion (start at 5J). If on amiodarone, halve the dose of digoxin. SES: Any arrhythmia (supraventricular tachycardia with AV block is suggestive), nausea, appetite, yellow vision, confusion, gynaecomastia. If toxicity is suspected, do an ECG (fig 3.19), digoxin levels, and check K+, Mg2+, and Ca2+. If toxicity is confirmed, stop digoxin, correct electrolyte imbalances, treat arrhythmias, and consider IV DigiFab® (p842). CIS: HCM; WPW syndrome (p133). Fig 3.19 This ECG shows the classic ‘reverse tick’ of digoxin toxicity: downsloping ST wave with rapid upstroke back to isoelec- tric line. The bradycardia is also suggestive of digoxin toxicity. Sodium channel blockers Class I anti-arrhythmics. Procainamide (1a) and lido- caine (1b) can be used to terminate VT. NB QT interval may be prolonged. Flecainide (1c) is useful for AF cardioversion in patients without contraindications, and for ar- rhythmia prophylaxis in patients with WPW or troublesome paroxysmal AF. CIS: Heart failure, IHD, valve disease, and heart block. Amiodarone A class III anti-arrhythmic. Amiodarone prolongs the cardiac action potential, reducing the potential for tachyarrhythmias. Used in both supra-ventric- ular and ventricular tachycardias, including during cardiac arrest. Broad range of side effects incl. thyroid disease, liver disease, pulmonary fibrosis and peripheral neuropathy. Monitor TFTs and LFTs every 6 months. Ivabradine Blocks the pacemaker ‘funny current’, slowing pulse rate without sig- nificantly dropping blood pressure. Used in angina, heart failure, and (off-licence) in autonomic tachycardia syndromes. CIS: Acute MI, bradycardia, long QT syndrome, shock. Many drug interactions, including with calcium antagonists. Statins Statins (eg simvastatin, p690) inhibit the enzyme HMG-COA reductase, which causes de novo synthesis of cholesterol in the liver. This increases LDL receptor ex- pression by hepatocytes leading to circulating LDL cholesterol. More effective if given at night, but optimum dose and target plasma cholesterol are unknown. SES: Muscle aches, abdominal discomfort, transaminases (eg ALT), CK, myositis, rarely rhabdomyolysis (more common if used with fibrates). Statins are generally well tol- erated. There are currently ~3 million people taking statins in England, which saves ~10 000 lives a year. See also hyperlipidaemia, pp690–1, fig 14.13. Anti-anginal drugs p116. Antihypertensives p140. Drugs that slow conduction through the atrioventricular node Drugs that slow conduction through the atrioventricular node (AVN) include di- goxin, verapamil, and adenosine. Uses include cardioverting AVNRT and diagnos- ing atrial tachycardias. Drugs that slow AVN conduction should be avoided in patients with aberrant pathways (eg WPW) as blocking the AVN can increase conduction via the alterna- tive pathways. AVN blockers are contraindicated in patients with or at risk of VT, eg those with long QT syndrome. 116 Angina pectoris If ACS is a possible diagnosis (including unstable angina), see pp798–801. Angina12 is symptomatic reversible myocardial ischaemia. Features: 1 Constricting/heavy discomfort to the chest, jaw, neck, shoulders, or arms. 2 Symptoms brought on by exertion. 3 Symptoms relieved within 5min by rest or GTN. Cardiovascular medicine All 3 features = typical angina; 2 features = atypical angina; 0–1 features = non- anginal chest pain. Other precipitants: emotion, cold weather, and heavy meals. Associated symptoms: dyspnoea, nausea, sweatiness, faintness. Features that make angina less likely: pain that is continuous, pleuritic or worse with swallowing; pain associated with palpita- tions, dizziness or tingling. Causes Atheroma. Rarely: anaemia; coronary artery spasm; AS; tachyarrhythmias; HCM; arteritis/small vessel disease (microvascular angina/cardiac syndrome X). Types of angina Stable angina: Induced by effort, relieved by rest. Good prognosis. Unstable angina: (Crescendo angina.) Angina of increasing frequency or severity; occurs on minimal exertion or at rest; associated with risk of MI. Decubitus angina: Precipitated by lying flat. Variant (Prinzmetal) angina: (BOX ‘Vasospastic angina’) Caused by coronary artery spasm (rare; may coexist with fixed stenoses). Tests ECG usually normal, but may show ST depression; flat or inverted T waves; signs of past MI. Blood tests: FBC, U&E, TFTs, lipids, HbA1c. Consider echo and chest X-ray. Further investigations are usually necessary to confirm an IHD diagnosis—see BOX. Management Address exacerbating factors: Anaemia, tachycardia (eg fast AF), thyrotoxicosis. Secondary prevention of cardiovascular disease: Stop smoking; exercise; dietary advice; optimize hypertension and diabetes control. 75mg aspirin daily if not contraindicated. Address hyperlipidaemia—see p690. Consider ACE inhibitors, eg if diabetic. PRN symptom relief: Glyceryl trinitrate (GTN) spray or sublingual tabs. Advise the pa- tient to repeat the dose if the pain has not gone after 5min and to call an ambulance if the pain is still present 5min after the second dose. SE: headaches, BP. Anti-anginal medication: (p114) First line: -blocker and/or calcium channel blocker (do not combine -blockers with non-dihydropyridine calcium antagonists). If these fail to control symptoms or are not tolerated, trial other agents. -blockers: eg atenolol 50mg BD or bisoprolol 5–10mg OD. Calcium antagonists: amlodipine—start at 5mg OD; diltiazem—dose depends on formulation. Long-acting nitrates: eg isosorbide mononitrate—starting regimen depends on formulation. Alternatives: GTN skin patches. SES: headaches, BP. Ivabradine: reduces heart rate with minimal impact on BP. Patient must be in sinus rhythm. Start with 5mg BD (2.5mg in elderly). Ranolazine: inhibits late Na+ current. Start at 375mg BD. Caution if heart failure, elderly, weight 40%. Group 2 licence holders must inform the DVLA of their ACS and stop driving; depending on the results of functional tests, they may be able to restart after 6wk. Work: how soon a patient can return to work will depend on their clinical progress and the nature of their work. They should be encouraged to discuss speed of return ± changes in duties (eg to lighter work if manual labour) with their employer. Some occupations cannot be restarted post-MI: eg airline pilots & air traffic controllers. Drivers of public service or heavy goods vehicles will have to undergo functional testing (eg exercise test), as mentioned previously. Fig 3.24 Acute postero-lateral MI. The posterior infarct is evidenced by the reciprocal changes seen in V1–3: dominant R waves (‘upside-down’ pathological Q waves) and ST depression (‘upside-down’ ST elevation). If extra chest leads were added (V7–9), we would see the classic ST elevation pattern, see p 98. The ST elevation in V6 sug- gests lateral infarction. A blockage in the circumflex coronary artery could explain both the posterior and lateral changes. 121 Cardiovascular medicine 122 Complications of MI Cardiac arrest (See p894, fig A3.) Cardiogenic shock (p802.) Left ventricular failure (p136, p800, p802.) Bradyarrhythmias Sinus bradycardia: See p808. Patients with inferior MIs may suffer atropine-unresponsive bradycardia due to infarction of nodal tissue. 1st-de- gree AV block: Most commonly seen in inferior MI. Observe closely as approximately Cardiovascular medicine 40% develop higher degrees of AV block (in which case calcium channel blockers and -blockers should be stopped). Wenckebach phenomenon: (Mobitz type I) Does not require pacing unless poorly tolerated. Mobitz type II block: Carries a high risk of developing sudden complete AV block; should be paced. Complete AV block: Usually resolves within a few days. Insert pacemaker (may not be necessary after inferior MI if narrow QRS, reasonably stable and pulse 40–50). Bundle branch block: MI complicated by trifascicular block or non-adjacent bifascicular disease (p132) should be paced. Tachyarrhythmias NB: K+, hypoxia, and acidosis all predispose to arrhythmias and should be corrected. Sinus tachycardia: Can  myocardial O2 demand, treat causes (pain, hypoxia, sepsis, etc.) and add -blocker if not contraindicated. SVT: p126. AF or flutter: If compromised, DC cardioversion. Otherwise, medical therapy as per p130. Frequent PVCs (premature ventricular complexes) and non-sustained VT (≥3 consecutive PVCS >100bpm and lasting 100bpm and lasting >30s.) Treat with synchronized DC shock (if no pulse, treat as per advanced life support algorithm, see p894, fig A3). Use anti-arrhythmics only if VT recurrent and not controlled with shocks. Consider abla- tion +/or ICD. Ventricular fibrillation: 80% occurs within 12h. VF occuring after 48h usually indicates pump failure or cardiogenic shock. : DC shock (see p894, fig A3), consider ICD. Right ventricular failure (RVF)/infarction Presents with low cardiac output and JVP. Fluid is key; avoid vasodilators (eg nitrates) and diuretics.20 Inotropes are re- quired in some cases. Pericarditis Central chest pain, relieved by sitting forwards. ECG: saddle-shaped ST elevation, see fig 3.51, p155. Treatment: NSAIDS. Echo to check for effusion. Systemic embolism May arise from LV mural thrombus. After large anterior MI, consider anticoagulation with warfarin for 3 months. Cardiac tamponade (p802) Presents with low cardiac output, pulsus paradoxus, Kussmaul’s sign,3 muffled heart sounds. Diagnosis: echo. Treatment: pericardial aspi- ration (provides temporary relief, see p773 for technique), surgery. Mitral regurgitation May be mild (minor papillary muscle dysfunction) or severe (chordal or papillary muscle rupture secondary to ischaemia). Presentation: pulmo- nary oedema. Treat LVF (p800) and consider valve replacement. Ventricular septal defect Presents with pansystolic murmur, JVP, cardiac failure. Diagnosis: echo. Treatment: surgery. 50% mortality in first week. Late malignant ventricular arrhythmias Occur 1–3wks post-MI and are the cardi- ologist’s nightmare. Avoid hypokalaemia, the most easily avoidable cause. Consider 24h ECG monitoring prior to discharge if large MI. Dressler’s syndrome (p698) Recurrent pericarditis, pleural effusions, fever, anae- mia, and ESR 1–3wks post-MI. Treatment: consider NSAIDS; steroids if severe. Left ventricular aneurysm This occurs late (4–6wks post-MI), and presents with LVF, angina, recurrent VT, or systemic embolism. ECG: persistent ST-segment elevation. Treatment: anticoagulate, consider excision. 3 JVP rises during inspiration. Adolf Kussmaul was a prominent 19th-century physician and the first to attempt gastroscopy. Inspired by a sword swallower he passed a rigid tube into the stomach, however light technology was limited and it was not until years later that gastroscopists could visualize the stomach. Coronary artery bypass graft (CABG) 123 CABG is performed in left main stem disease; multi-vessel disease; multiple se- vere stenoses; patients unsuitable for angioplasty; failed angioplasty; refractory angina. Indications for CABG—to improve survival: Left main stem disease. Cardiovascular medicine Triple-vessel disease involving proximal part of the left anterior descending. Indications for CABG—to relieve symptoms: Angina unresponsive to drugs. Unstable angina (sometimes). If angioplasty is unsuccessful. NB: when CABG and percutaneous coronary intervention (PCI, eg angioplasty) are both clinically valid options, NICE recommends that the availability of new stent technology should push the decision towards PCI. In practice, patients with single- vessel coronary artery disease and normal LV function usually undergo PCI, and those with triple-vessel disease and abnormal LV function more often undergo CABG. Compared with PCI, CABG results in longer recovery time and length of inpatient stay. Recent RCTs indicate that early procedural mortality rates and 5-year survival rates are similar after PCI and CABG. Compared with PCI, CABG probably provides more complete long-term relief of angina in patients, and less repeated revascu- larization. Procedure: The heart is usually stopped and blood pumped artificially by a ma- chine outside the body (cardiac bypass). Minimally invasive thoracotomies not requiring this are well described, 21 but randomized trials are few. The patient’s own saphenous vein or internal mammary artery is used as the graft. Several grafts may be placed. >50% of vein grafts close in 10yrs (low-dose aspirin helps prevent this). Internal mammary artery grafts last longer (but may cause chest- wall numbness). On-pump or off-pump: Seems to make little difference. 22 After CABG: If angina persists or recurs (from poor graft run-off, distal disease, new atheroma, or graft occlusion) restart antianginal drugs, and consider an- gioplasty. Ensure optimal management of hypertension, diabetes, and hyperlipi- daemia, and that smoking is addressed. Continue aspirin 75mg OD indefinitely; consider clopidogrel if aspirin contraindicated. Mood, sex, and intellectual prob- lems 23 are common early. Rehabilitation helps: Exercise: walkcycleswimjog. Drive at 1 month: no need to tell DVLA if non-HGV licences, p158. Return to work, eg at 3 months. 124 Arrhythmias—overview Disturbances of cardiac rhythm (arrhythmias) are: common often benign (but may reflect underlying heart disease) often intermittent, causing diagnostic difficulty see BOX ‘Continuous ECG monitoring’ occasionally severe, causing cardiac compromise which may be fatal. Cardiovascular medicine Emergency management: pp804–9. Causes Cardiac: Ischaemic heart disease (IHD); structural changes, eg left atrial dilatation secondary to mitral regurgitation; cardiomyopathy; pericarditis; myo- carditis; aberrant conduction pathways. Non-cardiac: Caffeine; smoking; alcohol; pneumonia; drugs (2-agonists, digoxin, L-dopa, tricyclics, doxorubicin); metabolic imbalance (K+, Ca2+, Mg2+, hypoxia, hypercapnia, metabolic acidosis, thyroid disease); and phaeochromocytoma. Presentation Palpitations, chest pain, presyncope/syncope, hypotension, or pulmo- nary oedema. Some arrhythmias may be asymptomatic, incidental findings, eg AF. History Take a detailed history of palpitations (p36). Ask about precipitating fac- tors, onset/offset, nature (fast or slow, regular or irregular), duration, associated symptoms (chest pain, dyspnoea, collapse). Review drug history. Ask about past medical history and family history of cardiac disease and sudden death. Syncope occuring during exercise is always concerning; the patient may have a condition predisposing them to sudden cardiac death (eg long QT syndrome). Tests FBC, U&E, glucose, Ca2+, Mg2+, TSH, ECG: Look for signs of IHD, AF, short PR interval (WPW syndrome), long QT interval (metabolic imbalance, drugs, congenital), U waves (hypokalaemia). 24h ECG monitoring or other continuous ECG monitoring (see BOX ‘Continuous ECG monitoring’). Echo to look for structural heart disease, eg mitral stenosis, HCM. Provocation tests: exercise ECG, cardiac catheterization ± electro- physiological studies may be needed. Narrow complex tachycardias: See pp806–7, 126. Atrial fibrillation and flutter: See pp806–7, 130. Broad complex tachycardias: See pp804–5, 128. Bradycardia: See p808 (causes and management of acute bradycardia) and p98 (heart block). Intermittent, self-resolving bradycardic episodes can cause significant problems (eg recurrent syncope). Continuous ECG monitoring (BOX ‘Continuous ECG monitoring’) will be needed to assist the diagnosis ±specialist tests (eg tilt table testing for reflex syncope). Seek out reversible causes, eg hypothyroidism or medica- tions such as -blockers. In some cases, no reversible cause is found and the inter- mittent bradycardia is sufficiently dangerous to warrant a permanent pacemaker (p132). See BOX, ‘Sick sinus syndrome’. Management Some arrhythmias can be managed conservatively, eg by reducing alcohol intake. Many arrhythmias respond to medical management with regular tablets or a ‘pill in the pocket’. Interventional management may include pacemakers (p132), ablation (eg of accessory pathways or arrhythmogenic foci), or implantable cardioverter defibrillators (ICDs), eg in patients with ventricular arrhythmias post-MI and in those with congenital arrhythmogenic conditions (p133). Continuous ECG monitoring 125 A simple 12-lead ECG only gives a snapshot of the heart’s electrical activities. Many disorders, particularly the arrhythmias, come and go and so may be missed at the time of the ECG recording. If you feel you are missing a paroxysmal arrhythmia, there are many ways of recording the electrical activity over a longer period: Telemetry: An inpatient wears ECG leads and the signals are shown on screens Cardiovascular medicine being watched by staff. Thus, if a dangerous arrhythmia occurs, help is immedi- ately available. This is very resource intensive so reserved for those at high risk of dangerous arrhythmias, eg immediately post-STEMI. Exercise ECGs: The patient exercises according to a standardized protocol (eg Bruce on a treadmill) and the BP and ECG are monitored, looking for ischaemic changes, arrhythmias, and features suggestive of arrhythmia risk, such as delta waves. Holter monitors: The patient wears an ECG monitor which records their rhythm for 24h–7d whilst they go about their normal life, this is later analysed. These can also be used to pick up ST changes suggestive of ischaemia. Loop recorders: These record only when activated by the patient— they cleverly save a small amount of ECG data before the event—use- ful if the arrhythmia causes loss of consciousness: the patient can press the button when they wake up. Loop recorders may be im- planted just under the skin (eg Re- veal® or the newer, injectable LINQ device), and are especially useful in patients with infrequent episodes as they can continually monitor for months or years awaiting an event (Fig 3.25). Fig 3.25 This is a recording from a loop recorder, each Pacemakers and ICDs: These re- line follows on from the one above. This tracing was cord details of cardiac electrical recorded at the time of a syncopal episode, it shows activity and device activity. This cardiac slowing then a 15sec pause: quite long enough information can be useful for es- to cause syncope! But not long enough to arrange a tablishing an arrhythmic origin for standard ECG, even if the patient were in hospital. symptoms. Reproduced from Camm et al., ESC Textbook of Cardio- vascular Medicine, 2009, with permission from Oxford University Press. Sick sinus syndrome Sick sinus syndrome is usually caused by sinus node fibrosis, typically in elderly patients. The sinus node becomes dysfunctional, in some cases slowing to the point of sinus bradycardia or sinus pauses, in others generating tachyarrhythmias such as atrial fibrillation and atrial tachycardia. Symptoms: Syncope and pre-syncope, light-headedness, palpitations, breathless- ness. Management: Thromboembolism prophylaxis if episodes of AF are detected. Permanent pacemakers for patients with symptomatic bradycardia or sinus pauses. Some patients develop a ‘tachy brady syndrome’, suffering from alternating tachycardic and bradycardic rhythms. This can prove difficult to treat medically as treating one circumstance (eg tachycardia) increases the risk from the other. Pacing for bradycardic episodes in combination with rate-slowing medications for tachycardic episodes may be required if the patient is symptomatic or unstable. 126 Narrow complex tachycardia Definition ECG shows rate of >100bpm and QRS complex duration of 100 and QRS complexes >120ms. If no clear QRS com- plexes, it is VF or asystole (or problems with the ECG machine or stickers). Principles of management If the patient is unstable or you are uncertain of what to do, get help fast—the patient may be periarrest (p804). Cardiovascular medicine Identify the underlying rhythm and treat accordingly. If in doubt, treat as ventricular tachycardia (VT)—the commonest cause. Giving AVN blocking agents to treat SVT with aberrancy when the patient is in VT can cause dangerous haemodynamic instability. Treating for VT when the patient is actually in SVT has less potential for deterioration. If WPW is suspected, avoid drugs that slow AV conduction—see p114. Differential diagnosis Ventricular fibrillation—chaotic, no pattern, fig 3.29. Ventricular tachycardia (VT), figs 3.12, 3.30. Torsade de pointes (polymorphic VT)—VT with varying axis (see fig 3.31), may look like VF. QT interval is a predisposing factor. Any cause of narrow complex tachycardias (p126) when in combination with bun- dle branch block or metabolic causes of broad QRS. Antidromic AVRT (eg WPW), p127. Differentiating VT from SVT with aberrancy This may be difficult; seek expert help. Diagnosis is based on the history (IHD increases the likelihood of a ventricular arrhythmia), a 12-lead ECG, and the response (or lack thereof) to certain medications. ECG findings in favour of VT: +ve or Ωve QRS concordance in all chest leads (ie all +ve (R) or all Ωve (QS)). QRS >160ms. Marked left axis deviation, or ‘northwest axis’ (QRS positive in aVR). AV dissociation (Ps independent of QRSs) or 2:1 or 3:1 Mobitz II heart block. Fusion beats or capture beats (figs 3.32, 3.33). RSR’ pattern where R is taller than R’. (R’ taller than R suggests RBBB.) Management See page 805. Ventricular extrasystoles (ectopics) These are common and can be symptomatic— patients describe palpitations, a thumping sensation, or their heart ‘missing a beat’. The pulse may feel irregular if there are frequent ectopics. On ECG, ventricular ectop- ics are broad QRS complexes; they may be single or occur in patterns: Bigeminy—ectopic every other beat, see fig 3.34. ECG machines may disregard the second QRS and so calculate the rate to be half the true value. Trigeminy—every third beat is an ectopic. Couplet—two ectopics together. Triplet—three ectopics together. Occasional ventricular ectopics24 in otherwise healthy people are extremely common and rarely significant. Frequent ectopics (>60/hour), particularly couplets and tri- plets, should prompt testing for underlying cardiac conditions. Post-MI, ventricular ectopics are associated with increased risk of dangerous arrhythmias. Pay attention to whether the ectopics all ‘look’ the same on the ECG suggesting a single focus (monomorphic) or may come from multiple foci (polymorphic). Causes and manage- ment can be different.  129 Cardiovascular medicine Fig 3.29 VF (p894). Fig 3.30 VT with a rate of 235/min. Fig 3.31 Torsade de pointes tachycardia. Fig 3.32 A fusion beat (*)—a ‘normal beat’ fuses with a VT complex creating an unusual complex. Fig 3.33 A capture beat (*)—a normal QRS amongst runs of VT. This would not be expected if the QRS breadth were down to bundle branch block or metabolic causes. Fig 3.34 Bigeminy—a normal QRS is followed by a ventricular ectopic beat * then a compensatory pause, this pattern then repeats. The ectopic beats have the same morphology as each other so probably all share an origin. 130 Atrial fibrillation (AF) and flutter AF25 is a chaotic, irregular atrial rhythm at 300–600bpm (fig 3.35); the AV node re- sponds intermittently, hence an irregular ventricular rhythm. Cardiac output drops by 10–20% as the ventricles aren’t primed reliably by the atria. AF is common in the el- derly (≤9%). The main risk is embolic stroke. Warfarin reduces this to 1%/yr from 4%. So, do an ECG on everyone with an irregular pulse (±24h ECG if dizzy, faints, palpita- Cardiovascular medicine tions, etc.). If AF started more than 48h ago, intracardiac clots may have formed, ne- cessitating anticoagulation prior to cardioversion. see BOX ‘Anticoagulation and AF’. Causes Heart failure; hypertension; IHD (seen in 22% MI patients); 26 PE; mitral valve disease; pneumonia; hyperthyroidism; caffeine; alcohol; post-op; K+; Mg2+. Rare causes: Cardiomyopathy; constrictive pericarditis; sick sinus syndrome; lung cancer; endocarditis; haemochromatosis; sarcoid. ‘Lone’ AF means no cause found. Symptoms May be asymptomatic or cause chest pain, palpitations, dyspnoea, or faintness. Signs Irregularly irregular pulse, the apical pulse rate is greater than the radial rate, and the 1st heart sound is of variable intensity; signs of LVF (p800). Examine the whole patient: AF is often associated with non-cardiac disease. Tests ECG shows absent P waves, irregular QRS complexes, fig 3.35. Blood tests: U&E, cardiac enzymes, thyroid function tests. Echo to look for left atrial enlargement, mitral valve disease, poor LV function, and other structural abnormalities. Managing acute AF If the patient has adverse signs (shock, myocardial ischaemia (chest pain or ECG changes), syncope, heart failure): ABCDE, get senior input DC cardioversion (syn- chronized shock, start at 120–150J) ± amiodarone if unsuccessful (p807); do not delay treatment in order to start anticoagulation. If the patient is stable & AF started 48h ago or unclear time of onset: rate control (eg with bisoprolol or diltiazem). If rhythm control is chosen, the patient must be anticoagulated for >3wks first. Correct electrolyte imbalances (K+, Mg2+, Ca2+);  associated illnesses (eg MI, pneu- monia); and consider anticoagulation (see BOX ‘Anticoagulation and AF’). Managing chronic AF The main goals are rate control and anticoagulation. Rate control is at least as good as rhythm control,27 but rhythm control may be appropriate if symptomatic or CCF younger presenting for 1st time with lone AF AF from a corrected precipitant (eg U&E). Anticoagulation: See BOX ‘Anticoagulation and AF’. Rate control: -blocker or rate-limiting Ca2+ blocker are 1st choice. If this fails, add digoxin (p115), then consider amiodarone. Digoxin as monotherapy in chronic AF is only acceptable in sedentary patients. Do not give -blockers with verapamil. Aim for heart rate 100mmHg systolic, no past LV dysfunction. Anticoagulate (See BOX ‘Anticoagulation and AF’). Consider ablation if symptomatic or frequent episodes. Atrial flutter See pp130–1, fig 3.35. Treatment: Similar to AF regarding rate and rhythm control and the need for anticoagulation.29 DC cardioversion is preferred to pharmacological cardioversion; start with 70–120J. IV amiodarone may be needed if rate control is proving difficult. Recurrence rates are high so radiofrequency ablation is often recommended for long-term management.  Anticoagulation and AF 131 Acute AF: Use heparin until a full risk assessment for emboli (see below) is made— eg AF started 48h, ensure ≥3wks of therapeutic anticoagulation before elective cardioversion; NB trans-oe- sophageal-guided cardioversion is an option if urgent cardioversion is required. Use a DOAC (eg apixaban) or warfarin (target INR 2–3) if high risk of emboli (past Cardiovascular medicine ischaemic stroke, TIA, or emboli; 75yrs with BP, DM; coronary or peripheral arte- rial disease; evidence of valve disease or LV function/CCF—only do echo if unsure). 30 Use no anticoagulation if stable sinus rhythm has been restored, no risk factors for emboli, and AF recurrence unlikely (ie no failed cardioversions, no structural heart disease, no previous recurrences, no sustained AF for >1yr). Chronic AF: Chronic AF may be paroxysmal (terminates in 7d), or permanent (long-term, continuous AF, sinus rhythm not achievable despite treatment). In all cases, the need for anticoagulation should be assessed using the CHA2DS2-VASc score to assess embolic stroke risk (consider anti- coagulation if score  >0,  >1), and balancing this against the risks of anticoagula- tion to the patient, assessed with the HAS-BLED score. Long-term anticoagulation should be with a DOAC (see p350) or warfarin. CHA2DS2-VASc—Congestive cardiac failure (1 point), Hypertension (1), Age 65–74y (1), Age >74y (2), Diabetes (1), previous Stroke/TIA/thromboembolism (2), Vascular disease (1), Sex Category (1 if female). A score of 2 = an annual stroke risk of 2.2%. Online calculators can be helpful, eg www.mdcalc.com. HAS-BLED—1 point for each of: labile INR age >65 use of medications that can predispose to bleeding (eg NSAIDs, anti-platelets) alcohol abuse uncontrolled hypertension history of, or predisposition to, major bleeding renal disease liver disease stroke history. Pre-excited AF In pre-excited AF, accessory pathways capable of conducting at rapid rates (eg sometimes in WPW syndrome) pass erratic electrical activity from the atria to the ventricles, unfiltered by the AVN. ECGs will show irregular, broad QRS complexes at >200bpm. Ventricles cannot sustain this rate for long; the patient is at high risk of VT and VF. (a) (b) (c) QRS QRS P P P P Fig 3.35 (a) AF: note the irregular spacing of QRS complexes and lack of P waves. (b) AF with a rapid ventricular response (sometimes referred to as ‘fast AF’). No pattern to QRS complex spacing, and rate >100bpm. (c) Atrial flutter with 2:1 block (2 P waves for every 1 QRS complex). The P waves have the classic ‘sawtooth’ appearance. Alternate P waves are merged with the QRS complex. 132 Pacemakers In normal circumstances the SAN plays the role of pacemaker. On occasion, other areas of myocardium will set the pace (see earlier in chapter). If the heart is not pacing itself fast enough, artificial pacing may be required. Options include ‘percus- sion pacing’—fist strikes to the precordium, used only in periarrest situations; trans- cutaneous pacing—electrical stimulation via defibrillator pads (p770); temporary Cardiovascular medicine transvenous pacing (p776); and a subcutaneously implanted permanent pacemaker. Indications for temporary cardiac pacing include Symptomatic bradycardia, unresponsive to atropine. After acute anterior MI, prophylactic pacing is required in: complete AV block Mobitz type I AV block (Wenckebach) Mobitz type II AV block non-adjacent bifascicular, or trifascicular block (p100). After inferior MI, pacing may not be needed in complete AV block if reasonably stable, rate is >40–50, and QRS complexes are narrow. Suppression of drug-resistant tachyarrhythmias by overdrive pacing, eg SVT, VT. Special situations: during general anaesthesia; during cardiac surgery; during elec- trophysiological studies; drug overdose (eg digoxin, -blockers, verapamil). See p776 for further details and insertion technique. Indications for a permanent pacemaker (PPM) include Complete AV block (Stokes–Adams attacks, asymptomatic, congenital). Mobitz type II AV block (p99). Persistent AV block after anterior MI. Symptomatic bradycardias (eg sick sinus syndrome, p125). Heart failure (cardiac resynchronization therapy). Drug-resistant tachyarrhythmias. Pre-operative assessment Bloods (FBC, clotting screen, renal function), IV cannula, consent, antibiotics as per local protocol. Post-operative management Prior to discharge, check wound for bleeding or hae- matoma; check lead positions and for pneumothorax on CXR; check pacemaker func- tion. During 1st week, inspect for wound haematoma or dehiscence. Other problems: lead fracture or dislodgement; pacemaker interference (eg from patient’s muscles); infected device. The battery needs changing every 5–10 years. For driving rules see p158. Pacemaker letter codes These enable pacemaker identification (min is 3 letters): 1st letter the chamber paced (A=atria, V=ventricles, D=dual chamber). 2nd letter the chamber sensed (A=atria, V=ventricles, D=dual chamber, O=none). 3rd letter the pacemaker response (T=triggered, I=inhibited, D=dual). 4th letter (R=rate modulation, P=programmable, M=multiprogrammable). 5th letter (P means that in tachycardia the pacemaker will pace the patient. S means that in tachycardia the pacemaker shocks the patient. D=dual ability to pace and shock. O=neither of these). Cardiac resynchronization therapy (CRT) Improves the synchronization of cardi- ac contraction and reduces mortality31 in people with symptomatic heart failure who have an ejection fraction 120ms.32 It involves biventricular pacing (both septal and lateral walls of the LV) and, if required, also an atrial lead. It may be combined with a defibrillator (CRT-D). ECG of paced rhythms (fig 3.13 and fig 3.36). Pacemaker input appears as a vertical ‘spike’ on the ECG. This spike can be very small with modern bipolar pacing systems. Ventricular pacing usually has a broad QRS morphology (similar to LBBB). Systems are usually programmed ‘on demand’ so will only pace when necessary. Modern systems are generally very reliable but pacing spikes with no capture afterwards suggests a problem. Programming of devices is complicated so seek help early if concerned. Many pacemakers store intracardiac electrograms which can be accessed to cor- relate rhythm with any symptoms.  133 Cardiovascular medicine Fig 3.36 ECG of a paced rhythm. Some pacemaker terms Fusion beat: Union of native depolarization and pacemaker impulse. Pseudofusion beat: The pacemaker impulse occurs just after cardiac depolariza- tion, so it is ineffective, but it distorts the QRS morphology. Pseudopseudofusion beat: If a DVI pacemaker gives an atrial spike within a na- tive QRS complex, the atrial output is non-contributory. Pacemaker syndrome: In single-chamber pacing, retrograde conduction to the atria, which then contract during ventricular systole. This leads to retrograde flow in pulmonary veins, and cardiac output, dyspnoea, palpitations, malaise, and even syncope. Pacemaker-mediated tachycardia: Retrograde conduction to the atrium is sensed by the pacemaker and ventricular pacing delivered in response. This again causes retrograde atrial conduction causing a repetitive sensing/pacing loop. This can be fixed by changing pacing programming parameters. Congenital arrhythmogenic cardiac conditions As well as the many acquired conditions that can predispose to arrhythmias (p125), there are a number of congenital conditions. These may be clinically silent until a fatal attack and are likely to be responsible for most cases of sudden adult death syndrome (SADS). They include: WPW syndrome (Wolff-Parkinson-White; fig 3.37.) Caused by congenital acces- sory conduction pathway between atria and ventricles. Resting ECG shows short PR interval, wide QRS complex (due to slurred upstroke or ‘delta wave’) and ST-T changes. Two types: WPW type A (+ve  wave in V1), WPW type B (Ωve  wave in V1). Tachycardia can be due to an AVRT or pre-excited AF/atrial flutter (p130). Manage- ment may include ablation of the accessory pathway. LQTS (Long QT syndromes.) These are channelopathies that result in prolonged repolarization phases, predisposing the patient to ventricular arrhythmias; classi- cally torsades de pointes. p804. Conditions associated with LQTS include Jervell and Lange-Nielsen syndrome (p702) and Romano–Ward syndrome (p710). ARVC (Arrhythmogenic right ventricular cardiomyopathy.) RV myocardium is re- placed with fibro-fatty material. Symptoms: palpitations and syncope during ex- ercise. ECG changes include epsilon wave; T inversion and broad QRS in V1–V3. Brugada Sodium channelopathy. Diagnosis: classic coved ST elevation in V1–V3 plus suggestive clinical history. ECG changes and arrhythmias can be precipitated by fever, medications (www.brugadadrugs.org), electrolyte imbalances, and ischaemia. Many of these patients can be treated medically or conservatively but those at high risk may require an implantable cardiac defibrillator (ICD). Screening family members is important for picking up undiagnosed cases. Fig 3.37 This patient has Wolff-Parkinson-White syndrome as they have delta waves (slurred QRS upstrokes) in beats 1 and 4 of this rhythm strip. The delta wave both broadens the ventricular complex and shortens the PR interval. If a patient with WPW has AF, avoid AV node blockers such as diltiazem, verapamil, and digoxin—but flecainide may be used. 134 Heart failure—basic concepts Definition Cardiac output is inadequate for the body’s requirements.33 Prevalence 1–3% of the general population; ~10% among elderly patients. 34 Key classifications Systolic failure: Inability of the ventricle to contract normally, resulting in cardiac output. Ejection fraction (EF) is 50%, this is termed HFpEF (heart failure with preserved EF). Causes: ventricular hypertrophy, constrictive pericarditis, tamponade, restric- tive cardiomyopathy, obesity. NB: systolic and diastolic failure pathophysiology often coexists. Left ventricular failure (LVF): Symptoms: dyspnoea, poor exercise tolerance, fa- tigue, orthopnoea, paroxysmal nocturnal dyspnoea (PND), nocturnal cough (± pink frothy sputum), wheeze (cardiac ‘asthma’), nocturia, cold peripheries, weight loss. Right ventricular failure (RVF): Causes: LVF, pulmonary stenosis, lung disease (cor pulmonale, see p194). Symptoms: peripheral oedema (up to thighs, sacrum, abdomi- nal wall), ascites, nausea, anorexia, facial engorgement, epistaxis. LVF and RVF may occur independently, or together as congestive cardiac failure (CCF). Acute heart failure: Often used exclusively to mean new-onset acute or decom- pensation of chronic heart failure characterized by pulmonary and/or peripheral oedema with or without signs of peripheral hypoperfusion. Chronic heart failure: Develops or progresses slowly. Venous congestion is common but arterial pressure is well maintained until very late. Low-output heart failure: Cardiac output is  and fails to  normally with exertion. Causes: Excessive preload: eg mitral regurgitation or fluid overload (eg renal failure or too rapid IV infusions, particularly in the elderly and those with established HF). Pump failure: systolic and/or diastolic HF (see above), heart rate (eg -blockers, heart block, post MI), negatively inotropic drugs (eg most antiarrhythmic agents). Chronic excessive afterload: eg aortic stenosis, hypertension. Excessive preload can cause ventricular dilatation, this exacerbates pump failure. Excessive afterload prompts ventricular muscle thickening (ventricular hypertro- phy), resulting in stiff walls and diastolic dysfunction. High-output heart failure: This is rare. Here, output is normal or increased in the face of needs. Failure occurs when cardiac output fails to meet these needs. It will occur with a normal heart, but even earlier if there is heart disease. Causes: anaemia, pregnancy, hyperthyroidism, Paget’s disease, arteriovenous malformation, beriberi. Consequences: initially features of RVF; later LVF becomes evident. Diagnosis Requires symptoms of failure (see above) and objective evidence of car- diac dysfunction at rest. For CCF, use the Framingham criteria. 35 Signs As described previously plus cyanosis, BP, narrow pulse pressure, pulsus al- ternans, displaced apex (LV dilatation), RV heave (pulmonary hypertension), signs of valve diseases. Severity can be graded using the New York classification (see BOX). Investigations According to NICE, 33 if ECG and B-type natriuretic peptide (BNP; p137) are normal, heart failure is unlikely, and an alternative diagnosis should be consid- ered; if either is abnormal, then echocardiography (p110) is required. Tests FBC; U&E; BNP; CXR (see fig 3.38); ECG; echo. ECG may indicate cause (look for evidence of ischaemia, MI, or ventricular hypertrophy). It is rare to get a completely normal ECG in chronic heart failure. Echocardiography is the key investigation. 36 It may indicate the cause (MI, valvular heart disease) and can confirm the presence or absence of LV dysfunction. Endomyocardial biopsy is rarely needed. Prognosis Poor with ~25–50% of patients dying within 5yrs of diagnosis. If admis- sion is needed, 5yr mortality ≈75%. Be realistic: in one study, 54% of those dying in the next 72h had been expected to live for >6months.37  New York classification of heart failure 135 I Heart disease present, but no undue dyspnoea from ordinary activity. II Comfortable at rest; dyspnoea during ordinary activities. III Less than ordinary activity causes dyspnoea, which is limiting. IV Dyspnoea present at rest; all activity causes discomfort. Cardiovascular medicine (a) (b) Fig 3.38 (a) The CXR in left ventricular failure. These features can be remembered as A B C D E. Alveolar oedema, classically this is perihilar ‘bat’s wing’ shadowing. Kerley B lines—now known as septal lines. These are variously attributed to interstitial oedema and engorged peripheral lym- phatics. Cardiomegaly—cardiothoracic ratio >50% on a PA film. Dilated prominent upper lobe veins (upper lobe diversion). Pleural Effusions. Other features include peribronchial cuffing (thickened bronchial walls) and fluid in the fissures. (b) ‘Bat’s wing’, peri-hilar pulmonary oedema indicating heart failure and fluid overload. 136 Heart failure—management Acute heart failure This is a medical emergency (p800). Chronic heart failure Stop smoking. Stop drinking alcohol. Eat less salt. Optimize weight & nutrition.33 Treat the cause (eg if dysrhythmias; valve disease). Treat exacerbating factors (anaemia, thyroid disease, infection, BP). Cardiovascular medicine Avoid exacerbating factors, eg NSAIDS (fluid retention) and verapamil (Ωve inotrope). Annual ’flu vaccine, one-off pneumococcal vaccine. Drugs: 1 Diuretics: Give loop diuretics to relieve symptoms, eg furosemide 40mg/24h PO or bumetanide 1–2mg/24h PO. Increase dose as necessary. SE: K+, renal im- pairment. Monitor U&E and add K+-sparing diuretic (eg spironolactone) if K+ 90%; specificity: 80–90%). The rises are greater with left than right heart failure and with systolic than diastolic dysfunction. What BNP threshold for diagnosing heart failure: If BNP >100ng/L, this ‘diag- noses’ heart failure better than other clinical variables or clinical judgement (his- tory, examination, and CXR). BNP can be used to ‘rule out’ heart failure if 50ng/L does not exclude other coexisting diseases; conditions that can cause BNP rises include tachycardia, cardiac ischaemia, COPD, PE, renal disease, sepsis, he- patic cirrhosis, diabetes, and old age. Also, assays vary, so liaise with your lab. Prognosis in heart failure: The higher the BNP, the higher the cardiovascular and all-cause mortality (independent of age, NYHA class, previous MI, and LV ejection fraction) and the greater the risk of sudden death. So, a patient whose symptoms are currently well controlled may benefit from more aggressive treatment if their BNP if persistently raised. 138 Hypertension Hypertension 44 is the most important risk factor for premature death and CVD; caus- ing ~50% of all vascular deaths (8≈106/yr). Usually asymptomatic, so regular screen- ing (eg 3-yrly) is a vital task—most preventable deaths are in areas without universal screening. 45 Defining hypertension BP has a skewed normal distribution (p751) within the popu- Cardiovascular medicine lation, and risk is continuously related to BP, so it is impossible to define ‘hyperten- sion’. 46 We choose to select a value above which risk is significantly increased and the benefit of treatment is clear cut, see below. Don’t rely on a single reading—assess over a period of time (how long depends on the BP and the presence of other risk factors or end-organ damage). Confirm with 24hr ambulatory BP monitoring (ABPM); or a week of home readings. NB: the diagnostic threshold is lower ~135/85mmHg. Whom to treat All with BP ≥160/100mmHg (or ABPM ≥150/95mmHg). For those ≥140/90, the decision depends on the risk of coronary events, presence of diabetes, or end-organ damage; see fig 3.40. 44 The HYVET study showed that there is even sub- stantial benefit in treating the over-80s. 47 Lower thresholds may be appropriate for young people—BP is on average lower in young people (eg 100–110/60–70 in 18-year- olds) and they have a ‘lifetime’ of risk ahead of them; but evidence to treat is lacking. White-coat hypertension Refers to an elevated clinic pressure, but normal ABPM (day average 200, diastolic>130mmHg) + bilateral retinal haemorrhages and exudates; papilloedema may or may not be present. Symptoms are common, eg headache ± visual disturbance. It requires urgent treatment, and may also pre- cipitate acute kidney injury, heart failure, or encephalopathy, which are hypertensive emergencies. Untreated, 90% die in 1yr; treated, 70% survive 5yrs. It is more com- mon in younger and in black subjects. Look hard for any underlying cause. Primary or ‘essential’ hypertension: (Cause unknown.) ~95% of cases. Secondary hypertension: ~5% of cases. Causes include: Renal disease: the most common secondary cause. 75% are from intrinsic renal disease: glomerulonephritis, polyarteritis nodosa (PAN), systemic sclerosis, chronic pyelonephritis, or polycystic kidneys. 25% are due to renovascular disease, most frequently atheromatous (elderly  cigarette smokers, eg with peripheral vascular disease) or rarely fibromuscular dysplasia (young ). Endocrine disease: Cushing’s (p224) and Conn’s syndromes (p228), phaeochromo- cytoma (p228), acromegaly, hyperparathyroidism. Others: coarctation (p156), pregnancy (OHCS p48), liquorice, drugs: steroids, MAOI, oral contraceptive pill, cocaine, amphetamines. Signs and symptoms Usually asymptomatic (except malignant hypertension, see earlier in topic). Headache is no more common than in the general population. Al- ways examine the CVS fully and check for retinopathy. Are there features of an un- derlying cause (phaeochromocytoma, p228, etc.), signs of renal disease, radiofemoral delay, or weak femoral pulses (coarctation), renal bruits, palpable kidneys, or Cush- ing’s syndrome? Look for end-organ damage: LVH, retinopathy and proteinuria—indi- cates severity and duration of hypertension and associated with a poorer prognosis. Tests To confirm diagnosis: ABPM or home BP monitoring. To help quantify overall risk: Fasting glucose; cholesterol. To look for end-organ damage: ECG or echo (any LV hypertrophy? past MI?); urine analysis (protein, blood). To ‘exclude’ secondary causes: U&E (eg K+ in Conn’s); Ca2+ ( in hyperparathyroidism). Special tests: Re- nal ultrasound/arteriography (renal artery stenosis); 24h urinary meta-adrenaline (p228); urinary free cortisol (p225); renin; aldosterone; MR aorta (coarctation). Grading hypertensive retinopathy 139 1 Tortuous arteries with thick shiny walls (silver or copper wiring, p560, fig 12.18). 2 AV nipping (narrowing where arteries cross veins, p560, fig 12.19). 3 Flame haemorrhages and cotton-wool spots. 4 Papilloedema, p560, fig 12.20. Cardiovascular medicine Measuring BP with a sphygmomanometer Use the correct size cuff. The cuff width should be >40% of the arm circum- ference. The bladder should be centred over the brachial artery, and the cuff applied snugly. Support the arm in a horizontal position at mid-sternal level. Inflate the cuff while palpating the brachial artery, until the pulse disappears. This provides an estimate of systolic pressure. Inflate the cuff until 30mmHg above systolic pressure, then place stethoscope over the brachial artery. Deflate the cuff at 2mmHg/s. Systolic pressure: appearance of sustained repetitive tapping sounds (Korotkoff I). Diastolic pressure: usually the disappearance of sounds (Korotkoff V). However, in some individuals (eg pregnant women) sounds are present until the zero point. In this case, the muffling of sounds, Korotkoff IV, should be used. State which is used for a given reading. For children, see OHCS p157. For advice on using automated sphygmomanometers and a list of validated de- vices see http://www.bhsoc.org/latest-guidelines/how-to-measure-blood-pressure/ Managing suspected hypertension Clinic blood pressure Clinic blood pressure Clinic blood pressure 38°C. Vascular phenomena (emboli, Janeway’s lesions, etc.). Immunological phenomena (glomerulonephritis, Osler’s nodes, etc.). Positive blood culture that does not meet major criteria. How to diagnose: Definite infective endocarditis: 2 major or 1 major and 3 minor or all 5 minor criteria. Antibiotic therapy for infective endocarditis Prescribe antibiotics for infective endocarditis as follows.66 For more information on individual antibiotics, see tables 9.4–9.9, pp386–7. Blind therapy—native valve or prosthetic valve implanted >1y ago: ampicillin, flucloxacillin and gentamicin. Vancomycin + gentamicin if penicillin-allergic. If thought to be Gram Ωve: meropenem + vancomycin. Blind therapy—prosthetic valve: vancomycin + gentamicin + rifampicin. Staphs—native valve: flucloxacillin for >4wks. If allergic or MRSA: vancomycin. Staphs—prosthetic valves: flucloxacillin + rifampicin + gentamicin for 6wks (re- view need for gentamicin after 2wks). If penicillin-allergic or MRSA: vancomycin + rifampicin + gentamicin. Streps—fully sensitive to penicillin: benzylpenicillin 1.2g/4h IV for 4–6wks.8 Streps—less sensitive: benzylpenicillin + gentamicin; if penicillin allergic or highly penicillin resistant: vancomycin + gentamicin. Enterococci: amoxicillin + gentamicin. If pen-allergic: vancomycin + gentamicin— for 4wks (6wks if prosthetic valve); review need for gentamicin after 2wks. HACEK organisms (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella): ceftriaxone for 4wks with native valve or 6wks with prosthetic. Fungal: Candida—amphotericin. Aspergillus—voriconazole. Fig 3.46 Clubbing with endo- Fig 3.47 Splinter haemorrhag- Fig 3.48 Janeway’s lesions are carditis. es are normally seen under the non-tender erythematous, hae- fingernails or toenails. They are morrhagic, or pustular spots, usually red-brown in colour. eg on the palms or soles. 8 If Strep bovis is cultured, do colonoscopy, as a colon neoplasm is the likely portal of entry (table 6.3, p249). 152 Diseases of heart muscle Acute myocarditis This is inflammation of myocardium, often associated with pericardial inflammation (myopericarditis).67 Causes: See table 3.3. Symptoms and signs: ACS-like symptoms, heart failure symptoms, palpitations, tachycardia, soft S1, S4 gallop (p44).Tests: ECG: ST changes and T-wave inversion, atrial arrhythmias, transient AV block, QT prolongation. Bloods: CRP, ESR, & troponin may be raised; viral Cardiovascular medicine serology and tests for other likely causes. Echo: diastolic dysfunction, regional wall abnormalities. Cardiac MR if clinically stable. Endomyocardial biopsy is gold stand- ard. : Supportive. Treat the underlying cause. Treat arrhythmias and heart failure (p136). NSAID use is controversial. Avoid exercise as this can precipitate arrhythmias. Prognosis: 50% will recover within 4wks. 12–25% will develop DCM and severe heart failure. DCM can occur years after apparent recovery. Dilated cardiomyopathy (DCM) A dilated, flabby heart of unknown cause. Associa- tions: alcohol, BP, chemotherapeutics, haemochromatosis, viral infection, autoim- mune, peri- or postpartum, thyrotoxicosis, congenital (X-linked). Prevalence: 0.2%. Presentation: Fatigue, dyspnoea, pulmonary oedema, RVF, emboli, AF, VT. Signs: Pulse, BP, JVP, displaced and diffuse apex, S3 gallop, mitral or tricuspid regurgita- tion (MR/TR), pleural effusion, oedema, jaundice, hepatomegaly, ascites. Tests: Blood: BNP (p137), Na+ indicates a poor prognosis. CXR: cardiomegaly, pulmonary oedema. ECG: tachycardia, non-specific T-wave changes, poor R-wave progression. Echo: glob- ally dilated hypokinetic heart and low ejection fraction. Look for MR, TR, LV mural thrombus. : Bed rest, diuretics, -blockers, ACE-i, anticoagulation, biventricular pac- ing, ICDs, LVADs, transplantation. Mortality: Variable, eg 40% in 2yrs. Hypertrophic cardiomyopathy (HCM) LV outflow tract (LVOT) obstruction from asymmetric septal hypertrophy. HCM is the leading cause of sudden cardiac death in the young. Prevalence: 0.2%. Autosomal dominant inheritance, but 50% are spo- radic. 70% have mutations in genes encoding -myosin, -tropomyosin, and troponin T. May present at any age. Ask about family history of sudden death. Symptoms and signs: Sudden death may be the first manifestation of HCM in many patients (VF is amenable to implantable defibrillators), angina, dyspnoea, palpitation, syncope, CCF. Jerky pulse; a wave in JVP; double-apex beat; systolic thrill at lower left sternal edge; harsh ejection systolic murmur. Tests: ECG: LVH; progressive T-wave inversion; deep Q waves (inferior + lateral leads); AF; WPW syndrome (p133); ventricular ectopics; VT. Echo: asymmetrical septal hypertrophy; small LV cavity with hypercontractile pos- terior wall; midsystolic closure of aortic valve; systolic anterior movement of mitral valve. MRI: see fig 3.16. Cardiac catheterization helps assess: severity of gradient; coronary artery disease or mitral regurgitation, but may provoke VT. Electrophysi- ological studies may be needed (eg if WPW, p133). Exercise test ± Holter monitor (p125) to risk stratify. : -blockers or verapamil for symptoms (the aim is reducing ventricular contractility). Amiodarone (p130) for arrhythmias (AF, VT). Anticoagulate for paroxysmal AF or systemic emboli. Septal myomectomy (surgical or chemical (with alcohol) to LV outflow tract gradient) is reserved for those with severe symp- toms. Consider implantable defibrillator—use http://www.doc2do.com/hcm/webHCM.html to assess risk of sudden cardiac death. Mortality: 5.9%/yr if 14yrs. Poor prognostic factors: age 300mL; fig 3.14. ECG shows low-voltage QRS complexes and may have alternating QRS morphologies (elec- trical alternans). Echocardiography shows an echo-free zone surrounding the heart. Management: Treat the cause. Pericardiocentesis may be diagnostic (suspected bacterial pericarditis) or therapeutic (cardiac tamponade). See p773. Send pericar- dial fluid for culture, ZN stain/TB culture, and cytology. Constrictive pericarditis The heart is encased in a rigid pericardium.68 Causes: Often unknown (UK); elsewhere TB, or after any pericarditis. Clinical features: These are mainly of right heart failure with JVP (with prominent x and y descents, p43); Kussmaul’s sign (JVP rising paradoxically with inspiration); soft, diffuse apex beat; quiet heart sounds; S3; diastolic pericardial knock, hepato- splenomegaly, ascites, and oedema. Tests: CXR: small heart ± pericardial calcification. CT/MRI—helps distinguish from re- strictive cardiomyopathy. Echo. Cardiac catheterization. Management: Surgical excision. Medical  to address the cause and symptoms. Cardiac tamponade A pericardial effusion that raises intrapericardial pressure, reducing ventricular filling and thus dropping cardiac output.68  Can lead rapidly to cardiac arrest. Signs: Pulse, BP, pulsus paradoxus, JVP, Kussmaul’s sign, muffled S1 and S2. Diagnosis: Beck’s triad: falling BP; rising JVP; muffled heart sounds. ECG: low-voltage QRS ± electrical alternans. Echo is diagnostic: echo-free zone (>2cm, or >1cm if acute) around the heart ± diastolic collapse of right atrium and right ventricle. Management: Seek expert help. The pericardial effusion needs urgent drainage (p773). Send fluid for culture, ZN stain/TB culture, and cytology. Fig 3.51 Pericarditis. Note the widespread ‘saddle-shaped’ ST elevation—particularly clear in V5 and V6. 155 Cardiovascular medicine 156 Adult congenital heart disease (ACHD) This is a growing area of cardiology as increasing numbers of children with congenital heart defects survive to adulthood, sometimes as a result of complex restructuring procedures which have their own physiological implications (see BOX ‘Patients with one ventricle’). ACHD69 patients are at increased risk of many conditions described else- where, for which many of the ‘standard’ investigations and therapies will apply: includ- Cardiovascular medicine ing arrhythmias (p124), heart failure (p134), and infective endocarditis (p150). Investigations Echocardiography (± bubble contrast) is first line. Increasingly, car- diac CT and MR are used to provide precise anatomical and functional information. Cardiac catheterization generates data on oxygen saturation and pressure in differ- ent vessels and chambers. Exercise testing assesses functional capacity. A few of the more common ACHDs are discussed below: Bicuspid aortic valve These work well at birth and go undetected. Many even- tually develop aortic stenosis (needing valve replacement) ± aortic regurgitation predisposing to IE/SBE ± aortic dilatation/dissection. Intense exercise may accelerate complications, so do yearly echocardiograms on affected athletes. 70 Atrial septal defect (ASD) A hole connects the atria. Ostium secundum defects: 80% cases; hole high in the septum; often asymptomat- ic until adulthood when a LR shunt develops. Shunting depends on the compliance of the ventricles. LV compliance decreases with age (esp. if BP), so augmenting LR shunting; hence dyspnoea/heart failure, typically aged 40–60yrs. Ostium primum defects: associated with AV valve anomalies, eg in Down’s syn- drome; present in childhood. Signs and symptoms: Chest pain, palpitations, dyspnoea. Arrhythmias incl. AF; JVP; wide, fixed split S2; pulmonary systolic flow murmur. Pulmonary hypertension may cause pulmonary or tricuspid regurgitation, dyspnoea and haemoptysis. Frequency of migraine. Simple tests: ECG: RBBB with LAD (primum defect) or RAD (secundum defect). CXR: small aortic knuckle, pulmonary plethora, atrial enlargement. Com- plications: Reversal of left-to-right shunt, ie Eisenmenger’s complex: initial LR shunt leads to pulmonary hypertension which increases right heart pressures until they exceed left heart pressures, hence shunt reversal. This causes cyanosis as de- oxygenated blood enters systemic circulation. Paradoxical emboli eg causing CVAs (veinartery via ASD; rare). Treatment: May close spontaenously. If not, primum de- fects are usually closed in childhood. Secundum defects should be closed if sympto- matic or signs of RV overload. Transcatheter closure is more common than surgical. Ventricular septal defect (VSD) A hole connects the ventricles. Causes: Congenital (prevalence 2:1000 births); acquired (post-MI). Symptoms: May present with severe heart failure in infancy, or remain asymptomatic and be detected incidentally in later life. Signs: Classically, a harsh pansystolic murmur is heard at the left sternal edge, with a systolic thrill, ± left parasternal heave. Smaller holes, which are haemo- dynamically less significant, give louder murmurs. Signs of pulmonary hypertension. Complications: AR, IE/SBE, pulmonary hypertension, Eisenmenger’s complex (above), heart failure from volume overload. Tests: ECG: normal, LAD, LVH, RVH. CXR: normal heart size ± mild pulmonary plethora (small VSD) or cardiomegaly, large pulmonary arteries and marked pulmonary plethora (large VSD). Cardiac catheter: step up in O2 saturation in right ventricle. Treatment: Initially medical as many close sponta- neously. Indications for surgical closure: failed medical therapy, symptomatic VSD, shunt >3 : 1, SBE/IE. Endovascular closure may be possible. 71 Coarctation of the aorta Congenital narrowing of the descending aorta; usually occurs just distal to the origin of the left subclavian artery. More common in boys. Associations: Bicuspid aortic valve; Turner’s syndrome. Signs: Radiofemoral delay; weak femoral pulse; BP; scapular bruit; systolic murmur (best heard over the left scapula); cold feet. Complications: Heart failure from high afterload; IE; intracer- ebral haemorrhage. Tests: CT or MRI-aortogram; CXR may show rib notching as blood diverts down intercostal arteries to reach the lower body, causing these vessels to dilate and erode local rib bone. Treatment: Surgery, or balloon dilatation ± stenting. Tetralogy of Fallot See p157. Fallot’s tetralogy: what the non-specialist needs to know 157 Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disorder (prevalence: 3–6 per 10 000). It is also the most common cyanotic heart defect that survives to adulthood, accounting for 10% of all ACHD. 72 It is believed to be due to abnormalities in separation of the truncus arteriosus into the aorta and pulmo- nary arteries early in gestation (fig 3.52). Cardiovascular medicine The ‘tetralogy’ of features are: 1 Ventricular septal defect (VSD). 2 Pulmonary stenosis. 3 Right ventricular hypertrophy. 4 The aorta overrides the VSD, accepting right heart blood. A few patients also have an ASD, which makes up the pentad of Fallot. Presentation: Severity of illness depends greatly on the degree of pulmonary stenosis. Infants may be acyanotic at birth, with a pulmonary stenosis mur- mur as the only initial finding. Gradually (especially after closure of the ductus arteriosus) they become cyanotic due to decreasing flow of blood to the lungs Fig 3.52 Tetralogy of Fallot. and increasing right-to-left flow across the VSD. Dur- Reproduced from Thorne et al., ing a hypoxic spell, the child becomes restless and Adult Congenital Heart Disease, 2009, with permission from agitated. Toddlers may squat, which is typical of TOF, Oxford University Press. as it increases peripheral vascular resistance, there- by decreasing the degree of right to left shunt. Adult patients are often asymp- tomatic. In the unoperated adult patient, cyanosis is common, although extreme cyanosis or squatting is uncommon. In repaired patients, late symptoms include exertional dyspnoea, palpitations, clubbing, RV failure, syncope, and even sudden death. Investigations: ECG shows RV hypertrophy with a right bundle-branch block. CXR may be normal, or show the hallmark of TOF, which is the classic boot- shaped heart (fig 3.53). Echocardiography can show the anatomy as well as the degree of stenosis. Cardiac CT and cardiac MRI can give valuable information for planning the surgery. 73 Management: Surgery is usually done be- fore 1yr of age, with closure of the VSD and correction of pulmonary stenosis. Prognosis: Without surgery, mortality rate is ~95% by age 20. After repair, 85% of pa- tients survive to 35yrs. Common problems in adulthood include pulmonary regurgitation, causing RV dilatation and failure; RV outflow Fig 3.53 Boot-shaped heart. tract obstruction; AR; LV dysfunction; and ar- Courtesy of Dr Edward Singleton. rhythmias. Patients with one ventricle Many patients born with single-ventricle hearts (eg hypoplastic left heart syn- drome) will undergo a Fontan procedure. This results in systemic venous blood flowing directly into the pulmonary arteries and the single ventricle being used to pump oxygenated blood into the aorta. The lack of a right heart results in many of the signs and symptoms of right heart failure and puts the patient at risk of rapid cardiac decompensation. When looking after these patients, seek advice from specialist ACHD centres. 158 Driving and the heart UK licences are inscribed ‘You are required by law to inform Drivers Medical Branch, DVLA, Swansea SA99 1AT at once if you have any disability (physical or medical), which is, or may become likely to affect your fitness as a driver, unless you do not expect it to last more than 3 months’. It is the responsibility of drivers to inform the DVLA (the UK Driving and Vehicle Licensing Authority), and that of their doctors to advise Cardiovascular medicine patients that medical conditions74 (and drugs) may affect their ability to drive and for which conditions patients should inform the DVLA. Drivers should also inform their insurance company of any condition disclosed to the DVLA. If in doubt, ask your defence union. The following are examples of the guidance for holders of standard licences; differ- ent rules apply for group 2 vehicle licence-holders (eg lorries, buses). More can be found at https://www.gov.uk/guidance/cardiovascular-disorders-assessing-fitness-to-drive. Angina Driving must cease when symptoms occur at rest or with emotion. Driving may recommence when satisfactory symptom control is achieved. DVLA need not be notified. Angioplasty Driving must cease for 1wk, and may recommence thereafter provided no other disqualifying condition. DVLA need not be notified. MI If successfully treated with angioplasty, cease driving for 1 week provided urgent intervention not planned and LVEF (left ventricular ejection fraction) >40%, and no other disqualifying condition. Otherwise, driving must cease for 1 month. DVLA need not be notified. Dysrhythmias Including sinoatrial disease, AF/flutter, atrioventricular conduction defects, and narrow or broad complex tachycardias. Driving must cease if the dys- rhythmia has caused or is likely to cause incapacity. Driving may recommence 4wks after successful control provided there is no other disqualifying condition. Pacemaker implant Stop driving for 1wk, the patient must notify the DVLA. Implanted cardioverter/defibrillator The licence is subject to annual review. Driving may occur when these criteria can be met: 6 months have passed since ICD implanted for secondary prevention. 1 month has passed since ICD implanted for primary prophylaxis. The device has not administered therapy (shock and/or symptomatic antitachycar- dia pacing) within the last 6 months (except during testing). No therapy (shock) in the last 2 years has been accompanied by incapacity (wheth- er caused by the device or arrhythmia)—unless this was a result of device malfunc- tion which has been corrected for at least 1 month or steps have been taken to avoid recurrence (eg ablation) which have been successful for at least 6 months. A period of 1 month off driving must occur following any revision of the device (generator and/or electrode) or alteration of antiarrhythmics. The device is subject to regular review with interrogation. There is no other disqualifying condition. Syncope Simple faint: No restriction. Unexplained syncope: With probable car- diac aetiology—4wks off driving if cause identified and treated; otherwise 6 months off. Loss of consciousness or altered awareness associated with signs of seizure requires 6 months off driving. If the patient is known to be epileptic or has had another such episode in the preceeding 5yrs, they must abstain from driving for 1yr. See driving and epilepsy (BOX). Patients who have had a single episod