Which S1 is characterized by a delay in the closure of the tricuspid valve?

Which S1 is characterized by a delay in the closure of the tricuspid valve?

• A. Accentuated
• B. Diminished
• C. Varying
• D. Split

Answer: (D)

First heart sound comes from the closures of the atrioventricular valves at the start of ventricular systole, with mitral closure (M1) and tricuspid closure (T1) forming its components. When the tricuspid valve closes after the mitral valve, those two components are heard separately instead of as a single sound. This separation within S1 is described as a split S1, and it directly reflects a delay in the closure of the tricuspid valve relative to the mitral valve. The term split conveys that there are two distinct closures occurring at different moments, which is why this option is the best choice. Accentuation or diminishment refer to how loud the sound is rather than its timing, and varying isn’t a standard descriptor for S1.

First heart sound comes from the closures of the atrioventricular valves at the start of ventricular systole, with mitral closure (M1) and tricuspid closure (T1) forming its components. When the tricuspid valve closes after the mitral valve, those two components are heard separately instead of as a single sound. This separation within S1 is described as a split S1, and it directly reflects a delay in the closure of the tricuspid valve relative to the mitral valve. The term split conveys that there are two distinct closures occurring at different moments, which is why this option is the best choice. Accentuation or diminishment refer to how loud the sound is rather than its timing, and varying isn’t a standard descriptor for S1.