What term describes the S4 gallop associated with hypertrophic obstructive cardiomyopathy?

The term that describes the S4 gallop associated with hypertrophic obstructive cardiomyopathy is the fourth heart sound. The S4 heart sound, also known as the "atrial gallop," occurs just before the first heart sound when the atria contract and force blood into a stiff or hypertrophied ventricle. In hypertrophic obstructive cardiomyopathy, the abnormal thickening of the ventricular wall leads to decreased compliance, making it more difficult for the ventricle to accommodate the incoming blood during diastole, thereby producing the S4 sound.

Recognizing the significance of the S4 sound in this condition is essential for understanding the cardiac dynamics present in patients with hypertrophic obstructive cardiomyopathy, as it provides insight into the heart's filling pressures and the state of ventricular function.