Stable Angina  

Definition:  

Stable angina is predictable chest discomfort due to myocardial ischemia, usually triggered by exertion or emotional stress, relieved by rest or nitrates. 

Aetiology / Causes:  

Atherosclerotic coronary artery disease (most common) 
Coronary artery spasm (less common)  
Severe anaemia  
 Tachyarrhythmias or  
hypertrophic cardiomyopathy 

Pathophysiology:  

– Imbalance between myocardial oxygen supply and demand  
– Supply decreased: fixed coronary stenosis  
– Demand increased: exercise, stress, tachycardia, hypertension – Leads to subendocardial ischaemia 

Clinical Features:  

– Chest discomfort: pressure, squeezing, heaviness  
– Location: retro-sternal, may radiate to left arm, jaw, neck, back  
– Triggers: exercise, emotional stress, cold – Relief: rest or sublingual nitrates  
– Duration: 2–10 minutes  
– Other symptoms: dyspnoea, diaphoresis, nausea  
– Pattern: predictable and reproducible 

Classification (CCS Angina Grading):  

– Class I: Ordinary activity does not cause angina  
– Class II: Slight limitation of ordinary activity  
– Class III: Marked limitation of ordinary activity  
– Class IV: Inability to carry out any physical activity without angina 

Diagnosis:  

– Clinical evaluation:  history + risk factors (HTN, DM, smoking, hyperlipidemia)  
– ECG: normal at rest, may show ST depression on stress  
– Stress testing: treadmill ECG, stress echo, nuclear perfusion scan 
– Coronary angiography: gold standard if severe or inconclusive  
– Lab tests: cardiac enzymes usually normal, lipid profile, HbA1c, kidney function 

Management:  

Lifestyle Modifications:  

– Smoking cessation, exercise, weight control, low-fat diet  
– Control HTN, diabetes, dyslipidemia 

Pharmacological Therapy:  

– Anti-anginals: nitrates (short- and long-acting), beta-blockers, calcium channel blockers, ranolazine  
– Secondary prevention: aspirin/clopidogrel, statins, ACE inhibitors/ARBs 

Revascularization: 

– PCI or CABG if symptoms persist or high-risk anatomy 

Prognosis:  

– Generally good with symptom control and risk factor management  
– Risk of progression to unstable angina or MI exists 

Key Points:  

– Predictable, relieved by rest/nitrates  
– Main cause: fixed atherosclerotic obstruction  
– Diagnosis: history + stress testing  
– Treatment: lifestyle, medications, risk factor control, possible revascularization  
– Watch for warning signs of unstable angina or ACS