What is an important feature to distinguish a diastolic murmur?

In the context of cardiac murmurs, a diastolic murmur is characterized by its timing during the cardiac cycle. Specifically, diastole is the phase of the heart cycle when the heart muscles relax and the chambers fill with blood. The most significant feature that distinguishes a diastolic murmur is its occurrence after the pulse, as the heart is not contracting (systole) at this time.

When the heart is filling with blood during diastole, any turbulence caused by valve abnormalities or hemodynamic changes can produce a murmur. Recognizing that a diastolic murmur happens after the pulse is crucial in differentiating it from systolic murmurs, which occur during the contraction phase when blood is ejected from the heart.

Other characteristics, such as whether the murmur is associated with a palpable thrill or if it is faint, do not specifically define a diastolic murmur. For instance, while a diastolic murmur can sometimes be faint or associated with a thrill, these features do not inherently distinguish it from systolic murmurs, which may also display similar characteristics. Thus, understanding the timing of the murmur is the key factor in identifying it as diastolic.