Remember the basic concept. In stable angina fixed atheroma grows to block 70%of vessel & in unstable form, this atheroma breaks up-to include platelets aggregation with dissemination.
⇒Insufficient blood flow to the heart muscle from narrowing of coronary artery may cause chest pain.
- Stable angina: reversible type. blocks occurs due to atheroma formation in coronary wall overtime. symptoms produce after >70 artery stenosis.
- Unstable angina: when atheroma raptures due too any cause, there occurs dissemination of thrombotic products with massive platelet aggregation leading to nearly complete obstruction and tissue necrosis. Unstable angina is part of acute coronary syndrome.
- variant angina(or Prinzmetal angina) : characterized by vasospasm of coronary arteries obstructing blood flow.
Signs & symptoms:
- Precipitation: exertion or emotional stress. Full stomach , cold temperature, pain may be accompanied by breathlessness, sweating and nausea.
- Chest discomfort: described as a pressure, heaviness, tightness, squeezing, burning, or chocking sensation.
- Pain: in the epigastrium(upper central abdomen), back, neck area, jaw and shoulders.
- Autoimmune symptoms: nausea, vomiting and pallor
- Major risk factors: age(≥55 years for men, ≥65 years for women),cigarette smoking, diabetes mellitus, dyslipidemia ,family history of premature cardiovascular disease, hypertension(HTN), kidney disease(microalbuminuria GFR<60ml/m2), obesity(BMI≥30kg/m2), physical inactivity, prolonged psychosocial stress
- Major contribution: profound anaemia, uncontrolled HTN, hyperthyroidism,hypoxemia, tachyarrhythmia, bradyarrhythmia, valvular heart disease, hypertrophic cardiomyopathy.
- Major cause: generalised imbalance between supply and demand of oxygen to myocardial tissue, failure of enough blood flow renders heart unable to perform its basic function.
- Resting ECG: during angina their is ST depression seen in the ECG with or without t wave inversion. ST elevation is seen in variants angina.
- Exercise ECG test: plan ST depression confirms angina. downward sloping ST segment indicated angina. Upward sloping ST segment indicates normal ECG.
- Chemical stress test: those unable to go exercise stress test, use stress chemicals digoxine to induce tachycardia mimicking stress.
- Angiogram: angiogram is done in diagnosed patients to check the need of invasive therapy.
- Cardiac markers: cardiac markers are done to rule out myocardial infarction.
- Blood test: complete blood test, lipid profile
- Generalised management: change in life style, smoking habits, regular exercise
- Beta blocker: selective Beta blocker , metaprolol(150-200mg), atenolol, bisprolol
- Anti-platelet therapy: anti-platelet therapy with aspirin(75mg low dose) and in case of toxicity copedogrel (75mg). Daily
- Nitroglycerine: sublingual nitroglycerine for acute case. (300-500μg)
- Calcium channel blocker: nifedipine can cause reflex tachycardia, so diltiazem and verapamil are prefered. They decrease afterload
- Invasive procedures: in case medication doesn’t improve symptoms, consider percutaneous intevention coronary artery bypass graft
Suspect angina in people presenting with tight, dull, or heavy chest discomfort which is:
›retrosternal or left side, radiating to left arm, neck, jaw or back
›associated with exertion or emotional stress and relieved within several minutes by rest
›precipitated by cold weather or meal
Ref. Davidson, Kaplan medicine