A myocardial infarction (2) has occurred with blockage of a branch of the left coronary artery (1). Myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to a part of the heart, causing damage to the heart muscle.
. A heart attack occurs when the blood supply to part of the heart stops and thus causes a section of the heart muscle to begin to die; whereas a cardiac arrest occurs when the heart stops beating as a whole.
