Ischemic Heart Disease: Angina and Myocardial Infarction Ischemic heart disease; syndromes causing an imbalance between myocardial oxygen demand and supply (inadequate myocardial blood flow) related to coronary arterial narrowing. Ischemia: insufficient tissue oxygenation. Infarction: a zone of tissue deprived of blood supply. Results of Ischemic Heart Disease Angina Pectoris; temporary ischemia Acute Myocardial Infarction; Temporary ischemia Sudden Cardiac Death Chronic Ischemic Heart Disease 1
Clinical manifestation: Pain, feeling pressure or compression in the anterior chest, pain radiated to the neck, jaw, or back; usually lasts 3 to 5 minutes. It is accompanied by feelings of constriction /suffocation. It usually occurs after exertion, and emotional excitement. ECG shows ST segment depression and T wave inversion during angina pain. Factors can produce anginal pain: Physical exertion, Exposure to cold can cause vasoconstriction, Eating heavy meal and Stress adrenalin B.P. Note; the pain of myocardial infarction is generally more severe and may be accompanied by sweating, nausea and a feeling of impending death or collapse Coronary artery disease is due to gradual and incomplete occlusion of the coronary vessels 2
by fatty deposits, accumulating in the endothelial cells lining the arterial walls. Complete occlusion of a diseased coronary artery may occur suddenly due to clot formation within the narrowing (coronary thrombosis). Coronary artery spasm or dissection of coronary arteries may be the causes. Risk Factors for Ischemic Heart Disease in Women Age >35 yr but 10% women with MI are under 35 Cigarette smoking and cardiac effects are more Pronounced in pregnancy Obesity, diabetes or cocaine abuse. Hypertriglyceride Family history of cardiovascular disease Hypertension Ethnicity Black and Asian women have higher risk In pregnancy, risk is increased by: pre-eclampsia and eclampsia phaeochromocytoma sickle cell and collagen vascular disease infection and postpartum hemorrhage (PPH) 3
Presentation in Pregnancy Can be confusing as chest discomfort, nausea and breathlessness are common in pregnancy and may be confused with gastro-esophageal reflux (heartburn) Typical presentation ischemic chest pain with an abnormal ECG and elevated cardiac enzymes (MI) Symptoms may be masked/unclear during labor ECG and cardiac enzymes can be insensitive Cardiac specific troponin I > 0.15 mg/ml is a more specific indicator of myocardial infarction than creatinine kinase muscle bone (CK MB) levels, which increase during normal labor Differential diagnosis of ischemic chest pain includes hemorrhage, sickle crisis, pre-eclampsia, acute pulmonary embolism and aortic dissection (systolic hypertension) There may be no symptoms at all, especially in diabetics 4
COMPLICATIONS 1. Arrhythmias ventricular tachycardia/fibrillation heart block 2. Hemodynamic problems pericarditis tamponade LVF cardiogenic shock acute mitral regurgitation 3. Mortality is 37 50% in pregnancy, specially if: infarct occurs late in pregnancy age < 35 years pulmonary/amniotic fluid embolism, hemorrhage, placental abruption, eclampsia, or drug toxicity arise Sudden severe chest pain in a previously fit pregnant woman may be caused by dissection of the aorta +/ coronary arterial dissection. If suspected, withhold thrombolytics and immediate CT/coronary angiography. 4. Coronary intervention depends on the site and size of the evolving infarct 5
5. Acute aortic dissection itself requires urgent surgery. NON-PREGNANCY TREATMENT AND CARE Wt management, smoking cessation and statins Glyceryl trinitrate (GTN) spray or SL tablets Early recognition and treatment of MI by history taking, ECG results and raised cardiac enzymes Pharmacological; aspirin, beta-blockers, ACEI, calcium channel blockers and statins Treat pain, nausea and vomiting Early thrombolysis/intervention improves outcome in MI Basic and advanced life support Angioplasty PRE-CONCEPTION ISSUES AND CARE Previous coronary bypass surgery does not of itself contraindicate pregnancy Impaired LVF is one of the main determinants of 6
Maternal and neonatal outcome Cardiological investigation including; echocardiography to evaluate left ventricular ejection fraction and exclude structural anomalies coronary angiography to ascertain disease severity +/ angioplasty/stenting echocardiography and exercise testing three months prior to stopping contraception is helpful Optimize medication prior to cessation of contraception: ACE inhibitors contraindicated aspirin9, beta-blockers and GTN to be encouraged as directed Promote smoking cessation Encourage daily exercise and weight reduction/control Advocate diet low in fat, salt and cholesterol Advise on stress avoidance, including control measures (deep breathing, muscle relaxation and imagery Management: Bed rest and avoid activities. O2 5L/min, fowler position. 7
Administer medication as prescribed to increase oxygenation and to reduce cardiac workload. Nitroglycerin: 5mg, direct relaxation of blood vessels and smooth muscles of coronary arteries lead to blood supply to myocardium. Pan should be relieved within 3 minutes. Reduce risk factors through diet, exercise, weight loss, smoking cessation, and stress reduction. Myocardial infarction Refers to the process by which myocardial tissue is destroyed because of reduced coronary blood flow due to Atherosclerosis or complete occlusion of an artery, embolus or thrombus. 8
Clinical manifestation: Crushing chest pain radiate to the shoulder + down the arms [not after effort or emotional upset] Dyspnea, pallor, diaphoresis, nausea + vomiting, elevated temperature. Note : rate of MI greater in male than female. Diagnostic evaluation: 1] A: History of present illness [duration, pain] B: History of previous illness [ BP., D.M] 2] ECG: enlarge Q wave, elevation or depressed ST segment and T wave inversion. 3] CPK most sensitive + reliable indicator in case of MI, p 6hrs return to normal in the 3rd day. 9
4] WBC shows increase count. Management Bed rest to O2 demand. Relieving chest pain, analgesics [morphine sulfate]. Vasodilators Nitroglycerine IV. [dilates both arteries + veins. Anticoagulant [ heparin]. Thrombolytic [streptokinase] dissolving thrombus. O2 administration. anxiety Patient education. 11
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