RIGHT AND LEFT ISOVOLUMIC VENTRICULAR RELAXATION-TIME INTERVALS COMPARED IN PATIENTS BY MEANS OF A SINGLE-PULSED DOPPLER METHOD

Right and left isovolumic ventricular relaxation time intervals measur ements were obtained as follows: from the peak R wave on the electroca rdiogram to either the mitral or the tricuspid pulsed Doppler flow tra ce onset minus the R to end-ejection zero flow crossing of the subaort ic (left side) or pulmonary (right side) D flow trace time interval: A ratio was calculated as a percent difference duration between both is ovolumic ventricular relaxation time intervals. The aim was to compare isovolumic ventricular relaxation time interval values in 42 healthy controls and to study the changes induced by heart diseases in 27 pati ents with (1) controlled hypertension without left ventricular hypertr ophy, (2) hypertrophic cardiomyopathy, and (3) Cor pulmonale. Mean val ues of isovolumic ventricular relaxation time intervals significantly differed at paired and unpaired studies, with right isovolumic ventric ular relaxation time intervals shorter than those of the left side in all groups (p < 0.001) except for patients with Cor pulmonale. Isovolu mic ventricular relaxation time intervals did not correlate with heart rate and moderately correlated with left ventricular mass and age. No significant difference was found between healthy controls and patient s with controlled hypertension. Significant changes were found in pati ents with hypertrophic cardiomyopathy and Cor pulmonale versus healthy controls for both isovolumic ventricular relaxation time intervals. H owever, significant changes in the ratio were only found in patients w ith Cor pulmonale (p < 0.005) because of abnormal similar values for b oth isovolumic ventricular relaxation time intervals. This Doppler met hod enabled, for the first time, serial comparison of isovolumic ventr icular relaxation time intervals with a homologous method. Both isovol umic ventricular relaxation time intervals significantly lengthened wi th age and with left ventricular indexed mass, but their ratio remaine d insignificantly changed except for patients with Cor pulmonale. The concomitant right and left isovolumic ventricular relaxation time inte rvals lengthening in patients with hypertrophic cardiomyopathy and Cor pulmonale suggests interdependence of both ventricles through the sep tum. This makes recommendable systematic comparison of both sides. The calculation of a ratio, free from the effect of factors intervening o n isovolumic ventricular relaxation time intervals, may, in addition, be of diagnostic help.