[Mitral flow propagation velocity assessed with M-mode color Doppler in patients with dilated cardiomyopathy].

BACKGROUND: The role of diastolic disfunction in the setting of severe left ventricular (LV) disfunction is usually forgotten due to difficulties in quantification and interpretation. The propagation velocity (PV) of mitral inflow into the left ventricle has been proposed as a load independent indicator of LV diastolic function. Our aim was to correlate PV with age, body surface, chambers dimensions, wall thickness and with classic parameters of systolic and diastolic function. We had in mind the validation of this index in the quantification of LV filling and in risk stratification of patients with dilated cardiomyopathy (DC). MATERIAL AND METHODS: We prospectively studied 32 consecutive patients, mean age 56.1 +/- 15.7 years, 22 (68.75%) male, mean ejection fraction 28.1 +/- 7.5%. All of them were in NYHA class < or = II and on ACE inhibitors. Eight (25%) were on beta-blockers. Patients without sinus rhythm, paced or with significant hypertensive, congenital or valvular heart disease were previously excluded. The following parameters of LV systolic function were assessed by echocardiography: fractional shortening, ejection fraction and cardiac output. LV filling was assessed by transmitral flow pulsed Doppler analysis: isovolumic relaxation time (IVRT), peak E and A wave velocities, E wave deceleration time (DT). We also evaluated a new Doppler index of combined systolic and diastolic myocardial performance (Tei index). PV (cm/s) was calculated by Color M-mode. Univariate regression analysis was performed (PV as dependent variable). RESULTS: We detected a high prevalence of diastolic function disturbances: 25 (78.1%) patients with a delayed relaxation pattern and only 3 (9.4%) with a restrictive pattern. PV did not correlate with age, body surface and LV geometry. There was a significant correlation between PV and E/A ratio (r = 0.61; p < 0.0001), IVRT (r = -0.50; p = 0.006), DT (r = -0.41; p = 0.01) and Tei index (r = -0.36; p = 0.04). CONCLUSIONS: Our results indicate that, in patients with a predominance of delayed relaxation, there is a strong relationship between PV and the classic parameters of LV filling. For similar levels of systolic impairment, PV could be an easy, fast and reproducible quantitative indicator of severity on DC.