What is a potential explanation for a heart murmur?

A heart murmur is an abnormal sound produced by turbulent blood flow within the heart, typically heard through a stethoscope. Valvular dysfunction is a primary cause of murmurs. This condition can arise when heart valves do not open or close properly, which can lead to abnormal blood flow patterns. For instance, a stenotic valve can restrict flow, while a regurgitant valve allows blood to flow backward. Both scenarios create turbulence, resulting in a murmur that is audible during a physical examination.

While dilated cardiomyopathy, coronary artery disease, and atrial septal defects can also lead to various cardiac abnormalities, they do not directly cause the characteristic turbulent flow that manifests as a murmur in the same way that valvular dysfunction does. Therefore, understanding the nature of heart murmurs is crucial, and recognizing valvular dysfunction as a key mechanism helps clarify why this option is the most relevant explanation.