Heart attack is called myocardial infarction. The heart blood vessels contain a fatty substance called plaque. Rupture of this plaque can cause sudden clot formation. This clot completely blocks the heart blood vessel suddenly. The blood supply as well as oxygen supply to the heart muscle stops completely. This manifests as sudden onset of chest pain.
Angina is chest discomfort due to insufficient blood supply to the heart muscle usually caused by blockage in the coronary arteries. The blockage in blood vessel is usually more than 70% and it develops gradually over a period of months to years.
It is not possible to differentiate between the two on the basis of symptoms alone. ECG is the initial test which should be done within the first 15 minutes of onset of chest pain. The ECG in a heart attack shows major changes called ST elevation. The ECG in angina may show minor changes. A coronary angiography should be done as early as possible. The coronary angiography helps us to understand the site, location and severity of the block. If the block is severe it is advisable to go ahead for an early angioplasty.
