Which of the following murmurs is typically heard in diastole?

The murmur typically heard in diastole is associated with tricuspid regurgitation. During diastole, the heart muscles relax, and the ventricles fill with blood. In the case of tricuspid regurgitation, the tricuspid valve fails to close properly during ventricular contraction, leading to backflow of blood from the right ventricle into the right atrium when the heart is filling during diastole. This backflow creates a continuous murmur that is best heard in the left lower sternal border, characteristic of a diastolic flow murmur.

Understanding the timing of heart murmurs is crucial in clinical assessments. Murmurs associated with other conditions listed—such as mitral regurgitation, aortic stenosis, and pulmonic stenosis—are typically associated with different phases of the cardiac cycle. Mitral regurgitation occurs during ventricular systole as blood flows backward from the left ventricle into the left atrium. Aortic stenosis and pulmonic stenosis also produce systolic murmurs due to turbulent blood flow during ventricular contraction through narrowed valves. Thus, tricuspid regurgitation is distinctive among the options provided for being a diastolic murmur.