Arrhythmias are irregular heartbeats caused by abnormal electrical activity, leading to too fast, too slow, or erratic rhythms. A myocardial infarction occurs when a blockage in a coronary artery reduces blood flow to part of the heart, damaging heart muscle tissue. Murmurs are abnormal sounds during heartbeat, caused by valve problems. Arrhythmias affect heart's rhythm, myocardial infarctions affect heart's muscle, murmurs are sounds linked to blood flow through valves.
