S3 Gallop

The S3 occurs during the rapid filling phase of early diastole (the y descent of the jugular venous waveform), 0.14-0.22 seconds after S2 (MUCH farther from S2 than a widely split S2). Unlike the split S2, the S3 is best heard over the apex of the heart using the bell of the stethoscope.

Card Tutorial

Patient 8

This is a middle-age man with ischemic cardiomyopathy complicated by chronic systolic heart failure, as well as a history of infective endocarditis involving the aortic and pulmonic valves, who was admitted to the hospital for an unrelated reason. He was noted to have a widely split S2 as well as an S3 gallop over the apex. Notice the duration between the two sounds of the split S2 is shorter than the duration between the S2 to the S3 gallop.