Prinzmetal (variant) angina is one of those Step 1 classics that looks like “regular angina” at first—until you notice the timing (rest/night), the EKG pattern (transient ST elevation), and the mechanism (coronary vasospasm, not fixed plaque). If you can distinguish it cleanly from stable angina and acute coronary syndromes, you’ll pick up easy points on vignettes and management questions.
Where Prinzmetal Angina Fits in Ischemic Heart Disease
Think of angina syndromes as different ways the myocardium gets transient ischemia:
| Syndrome | Trigger | Path | EKG during pain | Troponins | Key treatment |
|---|---|---|---|---|---|
| Stable angina | Exertion/stress | Fixed atherosclerotic narrowing | ST depression ± T inversion | Normal | Nitrates, beta-blocker, antiplatelet, statin |
| Unstable angina | Rest/new/worse | Plaque rupture → non-occlusive thrombus | ST depression/T inversion or normal | Normal (by definition) | ACS protocol (antiplatelets, anticoagulation, etc.) |
| NSTEMI | Often rest | Plaque rupture → partial occlusion | ST depression/T inversion | Elevated | ACS protocol |
| STEMI | Often rest | Complete occlusion | ST elevation | Elevated | Reperfusion |
| Prinzmetal angina | Rest, classically midnight–early AM | Coronary vasospasm | Transient ST elevation | Normal (unless prolonged spasm → infarct) | CCB, nitrates |
Definition (Step-Style)
Prinzmetal angina = episodic chest pain at rest due to transient coronary artery vasospasm, causing transmural ischemia that produces transient ST-segment elevation on EKG.
First Aid cross-reference (concepts):
- Cardiovascular → Ischemic heart disease/angina: Variant (Prinzmetal) angina = vasospasm; ST elevation, treated with CCBs.
Pathophysiology: What’s Actually Happening?
Core mechanism: vasospasm → transmural ischemia
- A focal spasm in an epicardial coronary artery causes a sudden, marked drop in blood flow.
- Because the ischemia can be transmural (full thickness), it produces ST elevation—similar to STEMI—but it’s transient and reversible.
Why does the spasm happen?
Not always a single cause, but common testable themes:
- Endothelial dysfunction → impaired nitric oxide–mediated vasodilation
- Hyperreactive vascular smooth muscle (increased vasoconstrictor response)
- Can occur with or without underlying atherosclerosis (but can coexist)
High-yield associations (know these cold)
- Smoking (very common association)
- Cocaine and amphetamines (sympathomimetic vasoconstriction)
- Other vasospastic disorders: Raynaud phenomenon, migraines (often mentioned as “vasospastic tendency”)
Clinical Presentation: How It Shows Up in Vignettes
Symptoms
- Anginal chest pain at rest
- Classically occurs at night/early morning (midnight to 8 AM is a common board phrasing)
- May occur in clusters (several episodes over days)
What relieves it?
- Nitrates relieve episodes (vasodilation)
- Calcium channel blockers prevent recurrence
What’s different from stable angina?
- Not reliably triggered by exertion
- Not primarily due to increased oxygen demand (it’s a supply issue from spasm)
Diagnosis: EKG, Response, and Provocation
EKG (during pain)
- Transient ST-segment elevation
- May see reciprocal changes depending on territory
- Between episodes, EKG can normalize
Biomarkers
- Troponins usually normal
- If spasm is prolonged → actual myocardial necrosis can occur → troponin elevation (rare but possible)
Angiography
- May show:
- Normal coronaries OR mild/moderate atherosclerosis
- Spasm can sometimes be observed
Provocative testing (conceptual)
- Spasm can be induced with ergonovine or acetylcholine during cath in controlled settings.
- Boards mainly want you to know these provoke spasm and reproduce symptoms/EKG changes.
High-yield differentiation tip:
If you see ST elevation + chest pain at rest but the episode resolves with nitrates and the patient has a vasospasm risk factor (e.g., smoking, cocaine), think Prinzmetal—not immediate “STEMI” unless there are persistent changes and biomarker rise.
Treatment: Acute Relief vs Prevention
Acute episode
- Sublingual nitroglycerin
- Relaxes vascular smooth muscle via increased NO → increased cGMP
Chronic prevention (mainstay)
- Calcium channel blockers (especially non-dihydropyridines like diltiazem/verapamil, but dihydropyridines also used)
- Decrease coronary vasospasm by inhibiting L-type calcium channels in smooth muscle
Avoid / caution
- Nonselective beta-blockers can worsen vasospasm (testable concept)
- Blocking -mediated vasodilation can leave unopposed vasoconstriction, particularly relevant in cocaine-associated chest pain.
Address triggers
- Smoking cessation
- Avoid cocaine/amphetamines and other provoking agents
High-Yield Associations & “Classic Step Clues”
The stem you should recognize
- Young-ish patient, few traditional CAD risk factors
- Smoker or cocaine use
- Chest pain at rest, nighttime
- Transient ST elevation that resolves
- Rapid relief with nitrates
- Prevent with CCBs
Common traps
- ST elevation does not automatically equal STEMI: duration/persistence + troponins + clinical course matter.
- Prinzmetal is not demand ischemia (unlike stable angina).
- Beta-blockers are not first-line here (and can be harmful in vasospastic settings).
Rapid Review: One-Minute Memory Hook
Prinzmetal (Variant) Angina
- Pain at rest (often Pre-dawn)
- Vasospasm (not fixed plaque)
- ST elevation (transient)
- Treat with Nitrates and CCBs
- Associated with Smoking, Stimulants (cocaine), Raynaud, Migraines
Mini Table: Step 1 “If You See X, Think Y”
| If you see… | Think… |
|---|---|
| Rest pain + transient ST elevation + nitrate response | Prinzmetal angina |
| Exertional pain + ST depression | Stable angina |
| Rest pain + ST depression + troponin negative | Unstable angina |
| Cocaine chest pain | Vasospasm risk; avoid nonselective beta-blockers; consider nitrates/CCBs |
First Aid Cross-References (Quick Map)
While page numbers vary by edition, these recurring First Aid anchors are consistent:
- Ischemic heart disease/Angina: stable vs unstable vs variant
- Drugs for angina: nitrates and calcium channel blockers for vasospasm
- Cocaine toxicity/cardiovascular effects: coronary vasoconstriction; beta-blocker caution (especially nonselective)
Key Takeaways (Exam-Ready)
- Prinzmetal angina is due to coronary vasospasm → transmural ischemia → transient ST elevation.
- Presents with chest pain at rest, often at night/early morning.
- Treat acute: nitrates. Prevent: calcium channel blockers.
- Strong associations: smoking, cocaine/amphetamines, and other vasospastic conditions (Raynaud, migraines).
- Differentiate from STEMI by transience, resolution with nitrates, and usually normal troponins.