S3 (gallop) is an abnormal heart sound. It is not usually present but may be heard after S2. It can be considered a normal sound in people under 40. But in those over 40, it can indicate heart ...

The fourth heart sound (S4), also known as the “atrial gallop,” occurs just before S1 when the atria contract to force blood into the left ventricle. If the left ventricle is noncompliant ...

Findings of mild to moderate heart failure (S3 gallop, rales < half-way up lung fields or elevated jugular venous pressure (mortality 17%) Class III: Pulmonary edema (mortality 38%) Class IV ...