Which sounds are categorized as abnormal heart sounds?

Abnormal heart sounds include those that deviate from the expected normal sounds of the heart. In this context, the third heart sound (S3), the fourth heart sound (S4), and heart murmurs are indicative of potential underlying cardiovascular issues.

The third heart sound, known as a physiological or pathological S3, can be a sign of heart failure or volume overload. It occurs early in diastole when blood strikes the ventricles, leading to vibrations that create the sound. The fourth heart sound (S4) typically signifies decreased ventricular compliance and is often associated with conditions such as hypertensive heart disease or left ventricular hypertrophy. Similarly, a heart murmur, which can either be innocent or pathological, is produced by turbulent blood flow—potentially indicating structural abnormalities within the heart or valve dysfunction.

Focusing on the other options, the sounds mentioned in those answers, such as S1 and S2, are considered normal heart sounds, representing the closure of the heart valves during the cardiac cycle. They are essential indicators of healthy cardiac function. The inclusion of terms like "normal" in the other options reinforces this understanding, as they do not encompass any sounds indicating pathological conditions often associated with abnormal findings in a clinical assessment.