Sudden death in mitral valve prolapse: associated accessory atrioventricular pathways.

Sudden death in patients with mitral valve prolapse is a rare complication with a possible arrhythmic mechanism. We made a detailed postmortem examination of the conduction system in three patients with MVP who died suddenly. One patient who died in cardiac failure had a normal conduction system. The two other patients with no cardiac symptoms prior to death had both accessory atrioventricular pathways. These findings suggest a higher incidence than hitherto known of accessory bypass tracts in patients with MVP who die suddenly, and support the presumption of an arrhythmic cause of death.