Prinzmetal's angina pectoris

Prinzmetal's angina pectoris (variant AP, vasospastic AP, angina pectoris inversa) is a specific type of angina pectoris.
 * It arises as a result of a spasm of an epicardial coronary vessels (a spasm can affect two or more coronary vessels at the same time)
 * On ECG we observe a transient elevation of the ST segment .

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

Etiopathogenesis


Vasoconstrictive stimulus (histamine, serotonin, ergonovin, acetylcholine, noradrenaline, blood PH) + local hyperreactivity of coronary arteries to vasoconstrictive stimulus → epicardial coronary artery spasm.

Most coronary spasms are clinically manifested as angina pectoris and resolve spontaneously. Longer-lasting spasms, however, can result in myocardial infarction, arrhythmia or sudden cardiac death.

Clinical signs
A typical symptom is angina pectoris. Their occurrence is often significantly higher depending on the weather and season; they are more common in autumn and winter in dry weather. Prinzmetal's AP can further induce a variety of arrhythmias from AV block to ventricular fibrillation ).

Diagnostics


In the case of a negative coronary angiographic examination, ST elevation capture during the attack is sufficient for the diagnosis of Prinzmetal's AP.
 * Prinzmetal's AP is not tied to physical activity. Angina occurs most often at night (median is 4 am).
 * During an episode of angina, ST elevation (or ST depression, inversion or pseudonormalization of the T wave) is observed on the ECG. Holter monitoring can be used to capture ST elevation.
 * Provocation tests: provocation with acetylcholine, methacholine, methylergonovine; provocation by exercise, cold, hyperventilation (hyperventilation echocardiography – the patient is allowed to hyperventilate during the echocardiography, which can initiate a coronary spasm, which is subsequently manifested by a disturbance in the kinetics of the ischemic region of the myocardium).

Treatment
Pharmacological therapy is similar to classical AP. Antiplatelet therapy is controversial.


 * Healthy lifestyle + elimination of provoking factors (smoking, alcohol, cocaine, emotional stress, hyperventilation, hypomagnesemia, severe cold).
 * Pharmacotherapy ( calcium channel blockers, nitrates ,  α-blockers )
 * Intracoronary stenting.
 * Sympathectomy (in resistant patients).

Beta-blockers are contraindicated because they increase the risk of spasms.

Related Articles

 * Angina pectoris
 * Sudden cardiac death
 * Heart-attack
 * Cardiotonics