Cardio| S4 Heart Sound

1.05 S4 Heart Sound. Cardiovacular system reveiw for the USMLE Step 1 exam. The S4 heart sound, also called an S4 gallop or atrial gallop, is an extra sound that is heard in late diastole, just before S1 It is caused by a stiff ventricle S4 is mostly pathogenic and almost never normal, unlike S3 It is associated with diseases that cause the ventricles to stiffen like hypertrophic cardiomyopathy and diastolic heart failure In the case of an athlete with physiological hypertrophy of the ventricles, growth of the ventricles can be a normal response to cardiovascular conditioning and lead to them developing an S4 heart sound S4 can be heard best when at the apex of the heart when the patient is placed in the left lateral decubitus position