Emergency Medicine Practice Test 2025 – Complete Exam Preparation

The S3 gallop, or third heart sound, is commonly associated with heart failure and is indicative of volume overload in the ventricles. This sound occurs during the rapid filling phase of the ventricles, which can happen when the heart is unable to pump effectively, leading to the accumulation of fluid. In heart failure, particularly with reduced ejection fraction, the ventricles may become dilated, and the increased blood volume can result in the S3 sound.

In patients with heart failure, the presence of an S3 is often a sign of underlying cardiac dysfunction and can be a critical finding during a physical examination, helping to differentiate between normal physiological states and those indicating heart failure. It is heard best at the apex of the heart with the patient in the left lateral decubitus position.

The S1 sound marks the closure of the mitral and tricuspid valves at the start of ventricular contraction, while the S2 sound occurs with the closure of the aortic and pulmonary valves at the end of ventricular contraction. These sounds are generally considered normal in healthy individuals regardless of heart failure status. The S4, or fourth heart sound, can occur in cases of left ventricular hypertrophy and stiffening of the heart due to conditions such as hypertension