Pitfall of pressure half time with acute alteration in preload in mitral stenosis

pp 195-198

Abstract

The mitral valve pressure half-time has been accepted as the basis for the Doppler quantification of valvular area in mitral stenosis. This method was described by Hatle and associates who suggested that the pressure half-time was independent of heart rate and cardiac output. However, recent studies have not validated the initial observations. In order to determinate the changes of pressure half-time and its realtionships with other hemodynamic variables of mitral flow, 14 consecutive patients in sinus rythm with mitral stenosis have been submitted to acute changes of preload by means of postural changes. After the echo-Doppler examination in the supine position, the mitral flow was determinated in Trendelemburg (T) and standing (S) position. The patients with other moderate to severe associated valvulopaty were excluded. Results: HR (beatsfmin); Basal (B): 71 ± 9; T: 72 ± 10* S: 77 ± 10**. E Vel (mfsec); B: 2.01 ± 0.43; T: 2.25±O.52**; S: 1.56±0.35**. Integral (cm): B: 70.8±22; T: 74.0±22**; S: 56.1±17**. PHT (msec); B: 206±63; T: 181± 51**; S: 280±93**; Area (cm2): B: 1.17±0.38; T: 1.33±0.44**; S: 0.89±0.33**. Conclusions: With the induction of acute changes of the preload, the E wave velocity, mitral flow integral and mitral valve area (as expression of pressure half-time) varies significantly and in the same direction: it increases in the Trendelemburg position anti decrease in the standing position.