What type of heart murmur begins at the first heart sound (S1) and continues to the second heart sound (S2)?

A holosystolic murmur, also referred to as a pansystolic murmur, is characterized by its continuous sound that starts with the first heart sound (S1) and extends through to the second heart sound (S2). This type of murmur occurs throughout the entire systolic phase of the cardiac cycle, indicating that there is a significant amount of turbulent blood flow occurring during this time.

The presence of a holosystolic murmur is often associated with conditions such as mitral regurgitation or ventricular septal defects, where blood flows backward from the ventricle into the atrium or through a defect in the septum during systole. This backflow leads to sustained turbulence, allowing the murmur to remain audible throughout the entirety of the systolic phase.

Understanding the distinct timing of heart murmurs is essential in clinical practice, as it can guide further evaluation and management of underlying cardiac conditions. In contrast, other types of murmurs such as diastolic or mid-systolic murmurs occur during different phases of the heart cycle, which differentiates them from holosystolic murmurs regarding their duration and the events in the cardiac cycle they coincide with.