What are early signs or symptoms of a heart attack?

What are early signs or symptoms of a heart attack?

Persistent chest pain radiating to the left arm, pallor, and rapid, weak pulse will be the most accurate answer, though some of the other symptoms could also occur in heart attack (myocardial infarction). For example, some have radiation to right arm. Laboured breathing can occur if myocardial infarction has resulted in left ventricular failure. Bradycardia is common in inferior wall myocardial infarction due to occlusion of right coronary artery.