Cardiology Heart Sounds

Split S1

S1 is generated by closure of the mitral and tricuspid valves. These paired left- and right-sided valves do not close at exactly the same time, but the human ear cannot distinguish sounds that are 0.02-0.03 seconds apart as 2 separate sounds. When conditions further delay tricuspid valve closure, a split S1 can be appreciated. One of the most common causes of delayed tricuspid valve closure is a right bundle branch block.
Card Tutorial

Patient 2

A young healthy physician volunteered to have his heart recorded because of a known split S1. The underlying cause is unknown.

Split S1

Annotated