Ischemic Heart Disease PDF

Ischemic Heart Disease by Osama El-Minshawy,MD Prof. of Medicine  Ischemic Heart Disease (IHD) IHD is the result of a limited blood supply to the heart muscle. 95% of cases, the cause of IHD is coronary blood flow reduction caused by coronary artery atheroscl...

Ischemic Heart Disease by Osama El-Minshawy,MD Prof. of Medicine  Ischemic Heart Disease (IHD) IHD is the result of a limited blood supply to the heart muscle. 95% of cases, the cause of IHD is coronary blood flow reduction caused by coronary artery atherosclerosis Ischemic heart disease is still the most common causes of death in the world.  IHD: Clinical Manifestations & Pathology Stable angina Ischemia due to athermomatous stenosis of coronary arteries Unstable angina Ischemia caused by dynamic obstruction of a coronary artery Due to plaque rupture Myocardial infarction Myocardial necrosis caused by acute occlusion of a coronary artery  IHD: clinical manifestations & pathology Heart failure Myocardial dysfunction due to infarction or ischaemia Arrhythmia Altered conduction due to ischemia or infarction Sudden death asystole  Stable Angina (Angina pectoris) Precipitating factors: Physical exertion Cold exposure Heavy meals Intense emotion Lying flat (decubitus angina) Vivid dreams (nocturnal angina) Clinical features Stable angina is characterized by central chest pain, discomfort or breathlessness that is precipitated by exertion or stress and is promptly relieved by rest.  Physical examination (search for) -Valve disease (particularly aortic), -Important risk factors (e.g. hypertension, diabetes mellitus), left ventricular Dysfunction (cardiomegaly, gallop rhythm) -Other manifestations of arterial disease -Conditions that may exacerbate angina (anemia, thyrotoxicosis). risk factors include cigarette smoking diabetes mellitus, hypertension hyper cholesterolemia, family history.  Investigations Resting ECG Occasionally, there is T-wave flattening or inversion in some leads, Exercise ECG An exercise tolerance test (ETT) is usually performed using a standard treadmill or bicycle ergometer protocol Coronary arteriography  Differential Diagnosis Other coronary syndromes (myocardial infarction) costochondritis Intercostal neuropathy, especially caused by herpes zoster Cervical or thoracic radiculopathy, including pre-eruptive zoster Esophageal spasm or reflux disease; cholecystitis Pneumothorax; pulmonary embolism; pneumonia.  Treatment sublingual nitroglycerin for episodes aspirin, long-acting nitrates, beta-blockers, and calcium channel blockers. Angioplasty with stenting considered in patients with anatomically suitable stenosis who remain symptomatic on medical therapy Bypass grafting.  Acute Coronary Syndrome Definition Acute coronary syndrome is a term that includes both unstable angina and myocardial infarction MI. Unstableangina is characterized by new-onset or rapidly worsening angina (angina on minimal exertion or angina at rest in the absence of myocardial damage. Myocardial infarction( MI ) occurs if there is evidence of myocardial necrosis, as demonstrated by an elevation in cardiac troponin or creatine kinase-MB isoenzyme  Pathology An acute coronary syndrome may present as a new phenomenon or against a background of chronic stable angina. This is a dynamic process whereby the degree of obstruction may either increase, leading to complete vessel occlusion, or regress due to the effects of platelet disaggregation and endogenous fibrinolysis. In acute MI, occlusive thrombus is almost always present at the site of rupture or erosion of an atheromatous plaque.  The thrombus may undergo spontaneous lysis over the course of the next few days, although by this time irreversible myocardial damage has occurred. Without treatment, the infarct-related artery remains permanently occluded in 20–30% of patients.  Investigations Electrocardiography(ECG):Elevated ST segment ,or hyperacut Twave *Plasma cardiac markers :(CK-MB) enzyme, and the cardiospecific proteins, troponins T and I *Chest X-ray This may demonstrate pulmonary oedema *Echocardiography This is useful for assessing left and right ventricular function and for detecting important complications such as mural thrombus, cardiac rupture, ventricular septal defect, mitral regurgitation and pericardial effusion.  Treatment Immediate management: the first 12 hours *Antithrombotic therapy *Antiplatelet therapy aspirin, , clopidogrel *Anticoagulants Anticoagulation reduces the risk of thromboembolic complications, and prevents reinfarction as unfractionated heparin, fractioned (low molecular weight) heparin or a pentasaccharide. *Anti-anginal therapy Sublingual glyceryl trinitrate calcium channel antagonist (e.g. nifedipine or amlodipine  *Reperfusion therapy *Coronary angiography and coronary revascularization *Primary percutaneous coronary intervention (PCI). *Thrombolysis:Alteplase (human tissue plasminogen activator)  Dental management of angina pectoris patients Treatment should start with taking complete medical history followed by premedication with anxiolytics or prophylactic nitroglycerin, nitrous oxide- oxygen sedation, and slow delivery of an anesthetic with epinephrine (1:1,00,000) coupled with aspiration. *Angina pain is often felt in the mandible, with secondary radiation to the neck and throat. Therefore, the patient may initially suspect the pain to be of dental origin. The dental environment increases the likelihood of an angina attack because of fear, anxiety, and pain. :  A patient who has an IHD episode in the dental chair should receive the following emergency dental treatment Dental procedure is discontinued & Patient is allowed to attain a comfortable position. Patient is reassured and encouraged to have his own NTG (up to 3 doses of NTG can be given in 15 min). -If angina do not resolve with this treatment within 2–3 min, administer another dose of nitroglycerin, monitor the patient's vital signs, call his or her physician, and be ready to accompany the patient to emergency department. -Oxygen is administered 4–6 lit/min. If no improvement within 3 min – Myocardial Infarction (MI) is suspected, patient is sent to the hospital Thank You