S4 Gallop

The S4 occurs in late diastole, just before S1, coinciding with atrial contraction (the a wave in the jugular venous waveform). It is generally present when the heart is so stiff that it is reliant upon a significant amount of filling via atrial contraction. Like the split S1, the S4 gallop is best heard over the apex of the heart. However, unlike the split S1, it is best heard with the bell of the stethoscope because of its low pitch.

Card Tutorial

Patient 4

This is a young man with cocaine-induced cardiomyopathy. Sometimes it is difficult to distinguish an S3 gallop from an S4 gallop when the patient is tachycardic. In this case, notice the sinus pause halfway through the second recording, proving that the gallop is an S4 ( it is the first sound on the next beat).