From the Guidelines
Variant angina, also known as Prinzmetal's angina, is the form of angina associated with coronary artery spasms and can occur during sleep.
Characteristics of Variant Angina
- It is a form of unstable angina that usually occurs spontaneously and is characterized by transient ST-segment elevation that spontaneously resolves or resolves with nitroglycerin (NTG) use without progression to myocardial infarction (MI) 1.
- The spasm is most commonly focal and can occur simultaneously at more than one site, even in coronary segments that are apparently normal on coronary angiography 1.
- Episodes of variant angina often occur in clusters, with prolonged asymptomatic periods of weeks to months, and can be precipitated by emotional stress, hyperventilation, exercise, or exposure to cold 1.
- A circadian variation in the episodes of angina is most often present, with most attacks occurring in the early morning hours 1.
Diagnosis and Treatment
- The key to the diagnosis of variant angina is the documentation of ST-segment elevation in a patient during transient chest discomfort, which usually occurs at rest and resolves when the chest discomfort abates 1.
- Diagnostic tests for Prinzmetal's angina are based on the recording of transient ST-segment elevation during an episode of chest pain, and may include continuous 12-lead ECG monitoring, treadmill exercise test, 2-dimensional echocardiogram, or the injection of a nuclear marker at the time of chest pain 1.
- Treatment consists of calcium antagonists, often at high doses, in association with nitrates, and it is useful to adapt the medication schedule as a function of the circadian variation in episodes of spasm 1.
From the Research
Form of Angina Associated with Coronary Artery Spasms
The form of angina associated with coronary artery spasms is known as variant angina or vasospastic angina 2, 3, 4, 5, 6.
Characteristics of Variant Angina
- It is caused by episodes of coronary artery spasm involving focal or diffuse changes in large and/or small coronary arteries 2
- It can occur at rest, particularly from midnight to early morning 3
- It is often debilitating and substantially under-diagnosed, occurring mainly in women 2
- It can be suspected on the basis of history and association with migraine, Raynaud's phenomenon, and Kounis syndrome 2
- Definitive diagnosis requires provocative testing at coronary angiography 2, 4
Triggers of Coronary Artery Spasm
- Stress 5
- Alcohol use 5
- Use of sympathomimetics 5
- Low environmental temperatures 5
- Smoking 5
- Vasoconstrictive nasal spray 5
- Exercise, cold pressor test, hyperventilation, Valsalva maneuver, and the administration of pharmacological agents such as sympathomimetic agents, beta-blocking agents, parasympathomimetic agents, ergot alkaloids, and alcohol 3