Holosystolic Murmur
The murmur described is holosystolic (also called pansystolic), as it begins with S1 and continues throughout systole until S2 without interruption, which in a patient with congestive heart failure most likely represents mitral regurgitation. 1
Defining Characteristics of This Murmur
- A murmur that begins with S1 and stops at S2 without any audible gap is by definition holosystolic (pansystolic), meaning it occupies the entire duration of systole 1
- The high-pitched, blowing quality further supports mitral regurgitation as the underlying cause, which is the most common etiology of holosystolic murmurs 1
- Pansystolic murmurs are typically plateau-shaped in configuration and are generated when blood flows between chambers with significant pressure differences throughout systole 1
Why This is NOT Other Murmur Types
- Midsystolic murmurs have a crescendo-decrescendo configuration and do not extend throughout the entire systolic period—they begin after S1 and end before S2, leaving audible gaps 2
- Late systolic murmurs begin in mid-to-late systole and are classically associated with mitral valve prolapse, not starting with S1 3, 4
- Middiastolic and presystolic murmurs occur during diastole, not systole, making them irrelevant to this clinical scenario 1
Clinical Context in Heart Failure
- In a patient with congestive heart failure, mitral regurgitation is a highly likely cause of a holosystolic murmur due to left ventricular dilation causing annular enlargement and functional mitral regurgitation 1
- The murmur of mitral regurgitation is typically best heard at the apex and radiates to the axilla 1
- Other causes of holosystolic murmurs include tricuspid regurgitation (best heard at lower left sternal border, increases with inspiration) and ventricular septal defects 1