Cardiology: Angina pectoris

Angina pectoris

Due to myocardial ischaemia, presents with chest pain or tightness that is relieved by rest
May radiate to jaw or arm
Other precipitants – emotion, cold weather and heavy metals
Associated symptoms – dyspnoea, nausea, sweatiness, faintness

Causes

Types

Stable angina – induced by effort relieved by rest
Unstable angina – angina of increasing frequency or severity (associated with increased risk of MI)
Decubitus angina – precipitated by lying flat
Prinzmental’s angina – caused by coronary artery spasm

Tests

ECG – may show ST depression and T wave inversion or flattening from previous MI
Exercise ECG
Thallium test
Coronary angiography
Exclude precipitating factors – anaemia, diabetes, hyperlipidaemia, thyrotoxicosis, GCA

Management

Change lifestyle
Treat modifiable risk factors – hypertension, DM
Aspirin – 75-150mg/24hr, reduces mortality by 34%
?-Blockers – Atenolol 50-100mg/24hr, unless CI (asthma, COPD, LVF, bradycardia, coronary artery spasm)
Nitrates – for symptoms give GTN spray or sublingual tabs every 30mins. For prophylaxis take regular oral nitrate e.g. isosorbide mononitrate 10-30mg BD or slow release nitrate 60mg/24hr
Calcium channel antagonists – amlodipine or diltiazem
If total cholesterol is >4mmol/L give a statin
Consider adding a K+ channel activator

Percutaneous transluminal coronary angioplasty (PTCA)

Involves balloon dilation of the stenotic vessel
Indications – poor response or tolerance to medication, refractory angina in patients not suitable for CABG, previous CABG, post-thrombolysis in patients with severe stenosis or positive stress test
Comparison wit PTCA and drug along show that PTCA may control symptoms better but with increased risk of early cardiac event
Complications – restenosis (20-30% in 6mths), emergency CABG (<3%), MI (<2%), death (<0.5%)
Stenting reduces rates of restenosis and need for bail out CABG
Drug coated stents and antiplatelet drugs reduced rates of restenosis

CABG

Indications – left main stem disease, multiple vessel disease, distal vessel disease, patient unsuitable for angioplasty, failed angioplasty
Comparisons between CABG and PTCA showed that CABG was better for symptom control and had a lower reintervention rate but required a longer recovery and inpatient stay

MDNotes