# Stable Angina Pectoris > Stable angina pectoris for NEET-PG Medicine covers Canadian grading, the anti-anginal drug ladder, nitrate precautions and revascularisation indications. - Canonical URL: https://prepelephant.com/topics/neet-pg/medicine/stable-angina-pectoris - Exam / course: NEET-PG · Subject: Medicine - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-08 - Last updated: 2026-10-08 - Reference basis: Harrison's Principles of Internal Medicine; ESC Guidelines on chronic coronary syndromes; Braunwald's Heart Disease - How to cite: "Stable Angina Pectoris", PrepElephant, https://prepelephant.com/topics/neet-pg/medicine/stable-angina-pectoris ## Direct answer Stable angina pectoris is exertional chest discomfort caused by a supply-demand mismatch in the coronary circulation, relieved by rest or sublingual nitrate within minutes. Management rests on three pillars: anti-ischaemic drugs that lower cardiac workload, secondary prevention with aspirin, a statin and blood pressure control, and revascularisation only when symptoms persist despite optimal medical therapy or when the anatomy carries a survival benefit, such as left main stenosis. ## What you must remember - **Canadian grading:** class I angina needs strenuous, rapid or prolonged exertion; class II appears on rapid stair climbing, uphill walking or after meals; class III limits walking to one or two blocks; class IV means symptoms at rest. - **First-line drugs:** beta blockers slow the heart and prolong diastolic filling; non-dihydropyridine calcium channel blockers such as verapamil or diltiazem are alternatives, and amlodipine is a useful add-on. - **Nitrates:** sublingual glyceryl trinitrate gives relief within about five minutes; phosphodiesterase-5 inhibitors such as sildenafil must be avoided for 24 hours beforehand, and 48 hours for tadalafil, because the combination causes profound hypotension. - **Add-on agents:** ranolazine, a late sodium current blocker, is added when angina persists, with QT prolongation as the main caution; ivabradine lowers heart rate in sinus rhythm when beta blockers are not tolerated. - **Secondary prevention:** aspirin, a high-intensity statin and blood pressure control are mandatory; an ACE inhibitor suits patients with diabetes, left ventricular dysfunction or hypertension, and smoking cessation is non-negotiable. - **Ischaemia testing:** stress imaging is preferred over a plain exercise ECG when the resting trace is abnormal, while coronary CT angiography suits low-to-intermediate probability patients without known disease. - **Revascularisation:** CABG improves survival in left main disease and in three-vessel disease with reduced ejection fraction; PCI relieves symptoms that stay refractory to optimal medical therapy. ## A graded pathway for exertional chest pain Consider a 58-year-old diabetic smoker whose pressing central discomfort on climbing two flights of stairs settles within minutes of rest. 1. **Confirm typical features:** The discomfort is retrosternal, pressure-like, provoked by exertion and relieved by rest or glyceryl trinitrate. 2. **Choose imaging:** With a high pre-test probability, functional or anatomical imaging is preferred to a plain exercise ECG. 3. **Treat without waiting:** Aspirin, a high-intensity statin, a beta blocker if there is no contraindication, and sublingual glyceryl trinitrate kept for attacks are started without waiting for the result. 4. **Escalate the drugs:** If angina persists at class II or III, amlodipine is added, and ranolazine or ivabradine follows, chosen by heart rate and kidney function. 5. **Refer for invasive assessment:** Invasive assessment comes only when symptoms remain disabling despite two or three anti-anginal drugs, or when imaging shows high-risk anatomy such as left main disease. 6. **Recognise instability:** Pain at rest, a crescendo pattern, or pain lasting more than twenty minutes despite nitrates demands urgent admission rather than outpatient titration. ## Where the exam tries to catch you Examiners test whether candidates recognise when stable angina has stopped being stable. - **Trap:** treating new angina at rest with more beta blockade — **Correct:** new angina at rest, or a sudden rise in frequency, is unstable until proven otherwise, and the answer is admission and antithrombotic therapy. - **Trap:** giving a non-selective beta blocker for variant angina — **Correct:** variant or Prinzmetal angina occurs at rest with transient ST elevation, and non-selective beta blockers can precipitate spasm by leaving alpha stimulation unopposed, so calcium channel blockers and nitrates are correct. - **Trap:** citing trimetazidine as first-line — **Correct:** it is widely prescribed in India but is only a second-line add-on in guidelines such as ESC, so citing it as first-line will lose marks. - **Trap:** giving sublingual nitrate after sildenafil that morning — **Correct:** a man who took sildenafil that morning is at risk of profound hypotension, so withhold nitrate until the interval has passed. ## Frequently asked questions ### Which Canadian Cardiovascular Society class describes angina on walking one or two blocks? Class III describes marked limitation, with angina on walking one or two blocks on level ground or climbing one flight of stairs at a normal pace. Class IV denotes angina at rest, while class II covers symptoms on rapid stairs, uphill walking or after meals. ### Why are beta blockers avoided in variant angina? Non-selective beta blockers leave alpha receptor stimulation unopposed, which can worsen coronary vasospasm in Prinzmetal or variant angina. Calcium channel blockers and nitrates are preferred in that setting, and beta blockers are reserved for typical exertional angina. ### What is the interval between sildenafil and sublingual nitrate? Sildenafil must be avoided for at least 24 hours before glyceryl trinitrate, and tadalafil requires 48 hours. Combining a phosphodiesterase-5 inhibitor with a nitrate can cause severe hypotension. ### When is CABG preferred over PCI for stable coronary disease? CABG is preferred for left main stem stenosis and for multivessel disease, particularly with diabetes or reduced ejection fraction, where surgery offers a survival advantage. PCI suits focal single-vessel disease, and its main role is symptom relief in patients who remain limited despite optimal medical therapy.