Effects of first myocardial infarction on left ventricular systolic and diastolic function with the use of mitral annular velocity determined by pulsed wave Doppler tissue imaging

This study was undertaken to assess the effect of a first myocardial Infarc tion CMI) on the systolic and diastolic velocity profiles of the mitral ann ulus determined by pulsed wave Doppler tissue imaging and thereby evaluate left ventricular (LV) function after MI. Seventy-eight patients with a firs t MI were examined before discharge. Peak systolic, peak early diastolic, a nd peak late diastolic velocities were recorded at 4 different sites on the mitral annulus corresponding to the septum, anterior, lateral and inferior sites of the left ventricle. In addition, the amplitude of mitral annular motion at the 4 above LV sites, the ejection fraction, and conventional Dop pler diastolic parameters were recorded. Nineteen age-matched healthy subje cts served as controls. Com pared with healthy subjects, the MI patients ha d a significantly reduced peak systolic velocity at the mitral annulus, esp ecially at the infarction sites. A relatively good linear correlation was f ound between the ejection fraction and the mean systolic velocity from the 4 LV sites (r = 0.74, P <.001). The correlation was also good when the mean peak systolic mitral annular velocity was tested against the magnitude of the mean mitral annular motion (r = 0.77, P <.001). When the patients were divided into 2 different groups with respect to an ejection fraction greate r than or equal to 0.50 or <0.50, a cutoff point of mean systolic mitral an nular velocity of greater than or equal to 7.5 cm/s had a sensitivity of 79 % and a specificity of 88% in predicting a preserved global LV systolic fun ction. Similar to systolic velocities, the early diastolic velocity was als o reduced, especially at the infarction sites. The peak mitral annular earl y diastolic velocity correlated well with both LV ejection fraction (r = 0. 66, P <.001) and mean systolic mitral annular motion (r = 0.68, P <.001). H owever; no correlation existed between the early diastolic velocity and con ventional diastolic Doppler parameters. The reduced peak systolic mitral an nular velocity seems to be an expression of regionally reduced systolic fun ction. The peak early diastolic velocity is also reduced, especially at the infarction sites, and reflects regional diastolic dysfunction. Thus, quant ification of myocardial velocity by Doppler tissue imaging opens up a new p ossibility of assessing LV function along its long axis.