What type of heart sound is commonly heard in hypertrophic cardiomyopathy?

In hypertrophic cardiomyopathy (HCM), the S4 heart sound is commonly heard due to the stiff left ventricle that results from hypertrophy. The S4 sound, also known as the atrial gallop, occurs when the left atrium contracts to push blood into a ventricle that is not relaxed enough to receive it comfortably, creating a vibration that produces the sound. This stiffening of the ventricular wall is characteristic of HCM, leading to decreased compliance and causing the left atrium to work harder.

The presence of S4 can be a significant clinical finding during auscultation, often indicating left ventricular hypertrophy and impaired diastolic filling. The other heart sounds or murmurs listed do not specifically relate to the characteristic auscultatory findings of HCM. For example, the S3 heart sound is often associated with heart failure due to volume overload, while a continuous murmur points to conditions like a patent ductus arteriosus. Split S2, typically seen in conditions like right bundle branch block or other situations affecting the timing of the aortic and pulmonic valve closure, is not a common finding in HCM either.