Which physical exam finding is most commonly associated with systolic heart failure with reduced ejection fraction?

• A. Fixed split S2
• B. Pericardial friction rub
• C. S3 gallop
• D. S4 gallop

Answer: (C)

In systolic heart failure with reduced ejection fraction, the ventricle is usually dilated and receives a large volume of blood that rushes in during early diastole. This rapid, passive filling against a compliant but overloaded ventricle creates a low-frequency sound after S2—the S3 gallop. It’s often described as a “ventricular” gallop and is classically associated with volume overload and reduced pumping function, making it the best clue to HFrEF on physical exam.

The other findings point to different problems: a fixed split S2 suggests an intracardiac shunt like an ASD, a pericardial friction rub indicates pericarditis, and an S4 gallop reflects a stiff, noncompliant ventricle typical of diastolic dysfunction or longstanding hypertension (HFpEF), not the dilated, systolic dysfunction seen in HFrEF.