Pansystolic murmur is present in all of the following cardiac conditions, EXCEPT:

**Core Concept**
A pansystolic murmur is a type of heart murmur that occurs throughout systole, the period of time when the heart contracts and pumps blood out to the body. This type of murmur is typically associated with regurgitant or incompetent valves, where blood leaks backward through the valve during systole.

**Why the Correct Answer is Right**
A pansystolic murmur is characteristic of conditions where there is an abnormality in the mitral or tricuspid valve, such as mitral regurgitation, tricuspid regurgitation, or ventricular septal defect (VSD). The murmur is caused by the regurgitation of blood through the incompetent valve or defect, resulting in a continuous flow of blood throughout systole. The murmur is often described as a low-pitched, rumbling sound that begins with the first heart sound (S1) and continues throughout systole.

**Why Each Wrong Option is Incorrect**
**Option A:** Mitral stenosis is a condition characterized by the narrowing of the mitral valve opening, which typically produces a diastolic murmur, not a pansystolic murmur. The murmur of mitral stenosis occurs when blood flows from the left atrium to the left ventricle through the narrowed valve during diastole.

**Option B:** Tricuspid stenosis is a condition characterized by the narrowing of the tricuspid valve opening, which typically produces a diastolic murmur, not a pansystolic murmur. The murmur of tricuspid stenosis occurs when blood flows from the right atrium to the right ventricle through the narrowed valve during diastole.

**Option C:** Atrial septal defect (ASD) is a condition characterized by an abnormal opening in the interatrial septum, which typically produces a systolic ejection murmur due to increased flow across the pulmonary valve, not a pansystolic murmur.

**Clinical Pearl / High-Yield Fact**
To remember the characteristic murmurs associated with different heart conditions, use the mnemonic "MURMURS": Mitral Regurgitation (pansystolic), Tricuspid Regurgitation (pansystolic), ASD (systolic ejection), Mitral Stenosis (diastolic), Tricuspid Stenosis (diastolic).

**Correct Answer: A. Mitral stenosis is a condition characterized by the narrowing of the mitral valve opening, which typically produces a diastolic murmur, not a pansystolic murmur.**