Evaluation of Left Ventricular Systolic Function by-M-Mode Echo/Phonocardiography and Automated Border Detection(ABD) Echocardiography

ABSTRACT

BACKGROUND: The rate of rise of left ventricular(LV) systolic pressure, dp/kt, and the peak ejection rate(PER) of LV may be more accurate indices for assessing LV systolic function than ejection fraction(EF). Both can be easily obtained by noninvasive methods, M-mode echo/phonocardiography and automated border detection(ABD) echocardiography, respectively. Mean dp/dt by M-mode echo/phonocardiography and PER by ABD echocardiography were compared with mean dp/dt by Doppler echocardiography. METHODS: Twenty-one adult patients who had normal sinus rhythm, mitral regurgitant signals by continuous wave Doppler echocardiography and an apical 4 chamber view of LV in which at least 75% of the endocardium was clearly visualized were selected for our study. The off-line estimation of LV end-diastolic volume (1) were performed by the method of disc, after manually tracing the endocardial border on the apical 4 chamber view and EF was calculated. M-mode echocardiography of the aortive valve and phonocardiography were simultaneously recorded on the strip chart to measure the isovolumic contraction time(dtM). A blood pressure (2) and LV end-diasolic pressure(LVEDP) was assigned 20mmHg in patients with Q wave myocardial infarction or EF< or =40% and 10mmHg in others. The mean dp/dtM during isovolumic contraction time was calculated as (aortic diastolic pressure-LVEDP)/dtM and was compared with the Doppler-derived mean rate of LV pressure rise(dp/dtDoppler) over the time period between velocities of 1 and 3m/sec on the ascending slope of the Doppler velocity spectrum. ABD system was used to measure the changes in LV volume and PER on the apical four chamber view. PER was compared with mean dp/dtDoppler. RESULTS: Mean dp/dtM positively correlated with mean dp/dtDoppler(r=0.73, p<0.001), but the limits of agreement between two methods were somewhat wide(-659-937mmHg/sec). PER also positively correlated with dp/dtDoppler and EF(r=0.73, p<0.001 ; r=0.80, p<0.001). CONCLUSIONS: Mean dp/dtM by M-mode echo/phomocardiography and PER by ABD echocardiography may be useful indices for assessing LV systolic function.