Prinzmetal's angina

Prinzmetal's angina (variant AP, vasospastic AP, angina inversa) is a specific type of angina.
 * It is caused by spasm of the epicardial coronary vessel (spasm can affect two or more coronary vessels simultaneously).
 * On ECG we observe transient ST segment elevation.

It was first described in 1959 by American cardiologist Myron Prinzmetal.

Etiopathogenesis


Vasoconstrictor stimulus (histamine, serotonin, ergonovine, acetylcholine, noradrenaline, blood pH) + local hyperreactivity of coronary arteries to vasoconstrictor stimulus → epicardial coronary artery spasm.

Most coronary spasms manifest clinically as angina pectoris and resolve spontaneously. However, prolonged spasms may result in myocardial infarction, arrhythmias or sudden cardiac death.

Clinical signs
The typical symptoms are angina. Their incidence is often significantly higher depending on the weather and season; they are more common in autumn and winter during cold weather. Furthermore, Prinzmetal's AP can cause a variety of arrhythmias (from AV block to ventricular fibrillation).

Diagnostics

 * Prinzmetal's AP is not tied to physical activity. Angina pectoris occurs most often at night (median is 4 am).
 * During an episode of angina pectoris, ST elevation (or ST depression, inversion or pseudonormalisation of the T wave) is observed on the ECG. Holter monitoring can be used to detect ST elevation.
 * Provocation tests: provocation by acetylcholine, methacholine, methylergonovine; provocation by exercise, cold, hyperventilation (hyperventilation echocardiography - the patient is hyperventilated during echocardiography, which may initiate coronary spasm, which subsequently results in disturbed myocardial ischemic kinetics).

If coronary angiography is negative, detection of ST elevation during an attack is sufficient to diagnose Prinzmetal's AP.

Treatment
Pharmacological therapy is similar to that for classic AP. Antiplatelet therapy is controversial. Betablockers are contraindicated because they increase the risk of spasm
 * Healthy lifestyle + elimination of provoking factors (smoking, alcohol, cocaine, emotional stress, hyperventilation, hypomagnesemia, rapid cooling).
 * Pharmacotherapy' (calcium channel blockers, nitrates, α-blockers).
 * Intracoronary stenting'.
 * Sympathectomy' (in resistant patients).

Related articles

 * Angina pectoris
 * Sudden cardiac death
 * Myocardial infarction
 * Cardiotonics