Dependence of Doppler echocardiographic transmitral early peak velocity on left ventricular systolic function in coronary artery disease

Abstract

The influence of systolic function on pulsed Doppler echocardiographic transmitral flow velocity patterns was assessed before and after postextrasystolic (PES) potentiation in 12 normal subjects (control group) and in 25 patients with previous healed myocardial infarction (MI) group. Simultaneous high-fidelity left ventricular pressure measurements were performed in all patients. A programmed single-coupled right ventricular extrasystole was induced during echocardiographic and subsequent cineangiocardiographic recordings. Adequate angiograms for volumetric analysis in both baseline and PES beats were obtained in 23 patients (7 in the control group and 16 in the MI group). PES potentiation of contraction was more pronounced in the MI group than in the control group. PES changes in ejection fraction, stroke volume and end-systolic volume were significantly greater in the MI group than in the control group (11 vs 5%, p < 0.005; 15 vs 5 ml/m 2, p < 0.005; and -13 vs -4 ml/m 2, p < 0.01, respectively). In contrast, PES potentiation prolonged the time constants of left ventricular pressure decline derived from exponential curve fits with a zero (Tw) and non-zero (Tb) asymptote pressure in the MI group to the same extent as in the control group (4 vs 5 ms, difference not significant [NS], and 9 vs 11 ms, NS, respectively). In the PES beat, peak E velocity remained unaltered (48 vs 49 cm/s, NS) in the control group, whereas it increased significantly (p < 0.0001) from 47 to 51 cm/s in the MI group. In contrast, peak E velocity normalized to time velocity integral during diastole, which is equivalent to volumetric peak filling rate normalized to stroke volume (SV), decreased after PES potentiation in both control and MI groups (from 5.2 to 4.7 SV/s, p < 0.005 and from 5.5 to 5.2 SV/s, p < 0.005, respectively). In conclusion, despite a prolonged relaxation, PES potentiation of contraction maintained peak E-wave velocity in the control subjects and enhanced H in patients with Ml. Early diastolic filling is strongly affected by systolic function. Thus, the influence of the preceding contraction should be accounted for in the Doppler echocardiographic assessment of early diastolic filling dynamics.