​Pathology - Angina Pectoris 
Stable angina is a condition that is mostly caused by the development of atherosclerosis.
Prinzmetal (variant) Angina: Linked to constriction of the coronary arteries
Unstable (crescendo) angina is the result of the breakdown of an atherosclerotic plaque, leading to partial thrombosis in the coronary artery.
Transient ischemia leading to insufficient myocardial oxygenation is the underlying etiology of all forms of angina.

Symptoms and signs 
Stable angina: Experiencing chest discomfort in the area around the heart during physical activity; the pain is alleviated by resting and using nitroglycerin; there are non-specific alterations in the ST-T segment on the electrocardiogram (ECG).
Prinzmetal angina: Occasional chest pain that happens when at rest; may show ST elevation on electrocardiogram (ECG).
Unstable angina: Chest pain that becomes more frequent over time, starting with exercise but eventually occurring even at rest. This is a warning sign that a heart attack may happen soon. It is possible to observe ST depressions on an electrocardiogram (ECG).

Therapy 
The following medications are considered stable: nitrates, B-blockers, statins, and aspirin.
Prinzmetal: Medications that dilate blood vessels (nitrates, calcium channel blockers).
Unstable patients should be treated with B-Blockers, statins, and aspirin. If coronary examination with catheterization is planned in the near future, it is advisable to consider heparin treatment.
Angina pectoris might be asymptomatic in individuals with diabetes.