MI/ acute coronary syndrome Flashcards
what is acute coronary syndrome?
Encompasses a range of presentations that could be STEMI, NSTEMI, unstable angina. Almost always associated with rupture of an atherosclerotic plaque and partial or complete thrombosis of the infarct-related artery.
Symtoms of acute coronary syndrome (5)
Palpitations Pain (pressure/squeezing/burning across precordium, may radiate to neck, shoulder, jaw, back, upper abdo or either arm) Exertional dyspnoea Sweating Nausea
Signs of ACS?
Hypo or hypertension Sweating Pulmonary oedema (LH failure) JV distension Extracardiac vascular disease Cold and clammy skin 3rd/4th heart sound Systolic murmur due to LV outflow obstruction Lung sounds
Investigations (9)
ECG (ST elevation or depression, T wave changes) Creatinine kinase isoenzyme MB (CK-MB) Troponin Myoglobin FBC Metabolites CXR Echocardiogram Cardiac angiogram
How many times should CK, troponin and myoglobin be measured?
Regular intervals until peak reached or 3x negative results
What would transient ST elevation suggest? Fixed?
Transient- angina, but also LV aneurysm, pericarditis, Wolff-Parkinson-White syndrome
Fixed- acute MI
Management (8)
Stabilise Relieve ischaemic pain Anti-thrombosis- aspirin, clopidogrel Nitrates (GTN, symptomatic relief) Beta blockers Heparin, LMWH, Factor Xa inhib Thrombolysis? Percutaneous coronary intervention
Complications
Pulomary oedema Ruptured papillary muscle, LV free wall, septum Heart failure Cardiogenic shock Mitral valve dysfunction Arrhythmias SA/AV node dysfunction DVT/PE- emboli Dressler's syndrome- autoimmune pericarditis Infarct extension Psych- depression
Differentials (10)
Acute pericarditis Anxiety Aortic stenosis Asthma Dilated cardiomyopathy Gastroenteritis Eosophagitis HTN emergency MI Myocarditis
How would you distinguish STEMI, NSTEMI and unstable angina?
ECG for STEMI
Biomarkers for NSTEMI vs angina
When does myoglobin peak?
2hrs
When does troponin peak?
12hrs
When does CK-MB peak?
10-24hrs
Risk factors for ACS (19)
ATHEROSCLEROSIS FACTORS: Age Male FHx Premature menopause Smoking DM HTN Dyslipidaemia Obesity Sedentary lifestyle
ACS FACTORS: Infected heart valve resulting in embolus Vasculitis Coronary artery spasm Cocaine use Congenital HD CKD Coronary trauma Increased O2 requirement e.g. hyperthyroid Reduced O2 delivery e.g. severe anaemia
