Cardiology Revision PDF

**CARDIOLOGY REVISION** **ECG** - **Rate:** divide number of big squares between two consecutive R waves - **Rhythm:** - Regularly irregular - sinus arrhythmia, atrial flutter - Irregularly irregular - atrial fibrillation, atrial flutter, 2nd degree heart block...

**CARDIOLOGY REVISION** **ECG** - **Rate:** divide number of big squares between two consecutive R waves - **Rhythm:** - Regularly irregular - sinus arrhythmia, atrial flutter - Irregularly irregular - atrial fibrillation, atrial flutter, 2nd degree heart block - **Axis:** I and II positive is normal, I positive and II negative is left axis deviation (leaving), I negative and III (± II) positive is right axis deviation (returning) - **P wave:** precedes each QRS complex, upright in II, III and aVF, inverted in aVR - Absent - atrial fibrillation, hyperkalaemia - Bifid - P mitrale (indicates left atrial hypertrophy, mitral stenosis) - Peaked - P pulmonale (indicates right atrial hypertrophy, pulmonary hypertension) - **PR interval:** 3-5 small squares (0.12-0.2s) - Shortened (faster AV conduction) - Wolff-Parkinson-White syndrome - Prolonged (slower AV conduction) - 1st degree heart block, hypokalaemia - **QRS complex:** \ - Prolonged (ventricular origin or aberrant conduction of supraventricular complexes) - bundle branch block, hyperkalaemia - Peaked - ventricular hypertrophy - Pathological Q waves - within a few days of an MI - **QT interval:** - Shortened - hypercalcaemia - Prolonged - hypokalaemia, hypocalcaemia, hypothermia, antiarrhythmics (amiodarone, flecainide), antimicrobials (erythromycin, clarithromycin, fluconazole, ketoconazole), antipsychotics, antidepressants, antiemetics - **ST segment:** isoelectric - Elevated - normal variant (high take-off), STEMI, vasospastic/variant/Prinzmetal angina, acute pericarditis (saddle-shaped) - Depressed - normal variant (upward sloping), NSTEMI, posterior MI (V1-V3), unstable angina, digoxin effect (downward sloping) - **T wave:** inverted in aVR and sometimes aVL, III, V1, V2 and V3 - Abnormal if inverted in I, II, aVF, V4-6 - Inverted in V5 and V6 - digoxin effect (reversed tick) - Peaked - hyperkalaemia, TCA overdose, within a few hours of an MI - Flattened - hypokalaemia, hypocalcaemia, within 24 hours of an MI - **Other waves:** - J wave - hypothermia - U wave - hypokalaemia - Delta wave - Wolff-Parkinson-White syndrome Hyperkalaemia - tall tented T waves, prolonged QRS complex, absent P waves, 'sine wave' pattern Hypokalaemia - "In hypokalaemia **U** have no **Pot** and no **T**ea, but a **long PR** and a **long QT**" +-----------------+-----------------+-----------------+-----------------+ | **I** Lateral | **aVR** | **V1** | **V4** Anterior | | | | Septal/anterior | | | Left circumflex | | | LAD | | artery | | LAD | | +=================+=================+=================+=================+ | **II** Inferior | **aVL ** | **V2** | **V5** Lateral | | | | Septal/anterior | | | RCA | | | Left circumflex | | | | LAD | artery | +-----------------+-----------------+-----------------+-----------------+ | **III** | **aVF** | **V3** Anterior | **V6** Lateral | | Inferior | Inferior | | | | | | LAD | Left circumflex | | RCA | RCA | | artery | +-----------------+-----------------+-----------------+-----------------+ - SAN - RCA in 60%, left circumflex artery in 40% (sinoatrial node branch) - AVN - RCA in 80%, left circumflex artery in 20% (atrioventricular node branch) **ANGINA** - Constricting discomfort in the chest, neck, shoulders, jaw or arms caused by an insufficient blood supply to the heart - \#1 coronary artery disease (other causes include valvular heart disease (aortic stenosis), HOCM, hypertension) - **Stable angina** - occurs with exertion or stress, relieved by rest or GTN within 5m - **Unstable angina** - occurs at rest, new onset or abrupt deterioration of stable angina, follow 'NSTEMI and unstable angina' tx - **Vasospastic/variant/Prinzmetal angina** - due to coronary artery spasm, ECG during pain shows ST elevation - Canadian Cardiovascular Society grading - Class I - sx on strenuous exertion - Class II - sx on moderate exertion - Class III - sx on mild exertion - Class IV - sx at rest - - - - - - - **ACUTE CORONARY SYNDROMES (ACS)** - STEMI and NSTEMI have troponin rise due to (mainly LV) myocardial cell death, unstable angina does not - But also raised in any cause of LV dysfunction, interventions which 'damage' the heart (CPR, defibrillation, cardioversion, ablation) and renal failure - 'Arrival to ECG' → 10 minutes, 'Door to needle' → 30 minutes Tx - 'MONAC' - **M**orphine 10mg IV + metoclopramide 10mg IV - **O**2 if hypoxic (\2mm in ≥2 adjacent anterior leads (V1-6) - New LBBB - Posterior MI (deep ST depression and tall R waves in V1-3) - \ - - High risk:  - - Likely to have coronary angiography - glycoprotein IIb/IIIa + UH **[Complications]** - **0-24h:** cardiac arrest (VF), AV block, acute heart failure, cardiogenic shock - **1-3d:** pericarditis - **3-14d:** - Papillary muscle rupture (can lead to mitral regurgitation) - Ventricular septal rupture - LV free wall rupture (can lead to cardiac tamponade) - **2w-mo: ** - Aneurysms (can lead to cardiac tamponade or mural thrombus formation thus systemic embolism) - persistent ST elevation on ECG - Dressler's syndrome - as pericarditis but later - Chronic heart failure **TACHYCARDIAS** **[Stable]** [Narrow complex tachycardia] *[Regular narrow complex tachycardia]* - Sinus tachycardia - AVRT - accessory pathway between atria and ventricles - Wolff-Parkinson White is an example of this. In WPW there is a congenital accessory pathway between atria and ventricles. ECG features include shortened PR interval, prolonged QRS complex with slurred upstroke 'delta' wave and axis deviation either LAD if right-sided pathway or RAD if left-sided pathway. Definitive Tx is with accessory pathway ablation. - AVNRT - circuit forms within AVN - Atrial flutter (fixed block) - \#1 vagal maneuvres - \#2 adenosine 6mg IV (12mg, 12mg) *[Irregular narrow complex tachycardia]* - Sinus arrhythmia (rate changes with inspiration/expiration) - Atrial fibrillation - Can be first-detected, paroxysmal (\