What is the most common cause of death following a myocardial infarction?

The most common cause of death following a myocardial infarction is a fatal arrhythmia (heart rhythm disturbance). Arrhythmias occur when the electrical signals that coordinate the heart's activity are disrupted, causing the heart to beat too fast, too slow, or irregularly. This can lead to a sudden cardiac arrest and, if not immediately treated, result in death.