Such patients may feel quite well. They survived their myocardial infarction and may have slight or even moderate reduction of exercise ability, but by 'pacing' themselves, such patients can lead relatively normal lives. They may be aware of their arrhythmia because of short periods of palpitations which may only trouble them transiently. Consequently, this group of patients, many still in the prime of their lives, are at relatively high risk of dying suddenly.