Variant Angina, or Prinzmetal Angina, is discomfort occurring mainly during rest, often at night, and only rarely and inconsistently during exertion. Attacks tend to occur regularly at certain times of day.

Unstable angina is chest pain that happens suddenly and becomes worse over time. It occurs seemingly without cause. It can happen when you’re at rest or even asleep. An attack of unstable angina may lead to a heart attack. For this reason, an attack of unstable angina is an emergency and you should seek immediate medical treatment.

Unstable angina is a signal that your arteries are becoming very narrow and that you could experience a heart attack. If left untreated, unstable angina can lead to heart attack, heart failure, or arrhythmias (irregular heart rhythm). These can be life-threatening conditions.

Stable angina, also called angina pectoris, is the most common type of angina. Stable angina is a predictable pattern of chest pain. You can usually track the pattern based on what you’re doing when you feel the pain in your chest. Tracking stable angina can help you manage your symptoms more easily.

This type of angina, or chest pain, may be a symptom of coronary microvascular disease (MVD). Coronary MVD is heart disease that affects the heart’s smallest coronary artery blood vessels.

Causes

Spasms within the walls of these very small arterial blood vessels causes reduced blood flow to the heart muscle leading to a type of chest pain referred to as microvascular angina.