Two patients with rheumatic mitral stenosis are compared. Patient X has an A2 to opening snap interval of 0.06 seconds; Patient Y has an A2 to opening snap interval of 0.12 seconds. What does this comparison indicate?
- A Patient X has the more severe mitral stenosis ✓
- B Patient Y has the more severe mitral stenosis
- C Both have equally severe stenosis since the interval does not correlate with severity
- D The interval reflects right ventricular hypertrophy, not mitral stenosis severity
Correct answer: A. Patient X has the more severe mitral stenosis
Explanation
The B2 to opening snap interval shortens as mitral stenosis worsens, because higher left atrial pressure causes the pressure crossover between left atrium and left ventricle to occur sooner after aortic valve closure. An interval near 0.06 seconds indicates severe stenosis, while an interval approaching 0.12 seconds suggests milder disease. This bedside clue correlates with the echo-derived mitral valve area and transmitral gradient.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.