Noninvasive Evaluation of Left Ventricular Relaxation by Apexcardiogram in Man

心尖拍動図による各種心疾患での左室拡張期待性について

Noninvasive Evaluation of Left Ventricular Relaxation by Apexcardiogram in Man

Creators Okayama Akira

To evaiuate left ventricular (LV) relaxation, apexcardiogram (ACG), phonocardiogram (PCG) and electrocardiogram (ECG) were recorded simultaneously in 55 patients [17 normal (NOR), 17 hypertrophic cardiomyopathy (HCM) 13 dilated cardiomyopathy (DCM) and 8 hypertention (HT)]. LV pressure was measured by Millar's micromanometer during cardiac catheterization which was performed within a week after ACG study. Iia-O was taken as the time interval between Iia (aortic component of the second heart sound) and the O-point of ACG. △T was defined as the time interval from the point of ACG coincided with Iia to the point of the downstroke of ACG where the curve had fallen to 50% of the height of the deflection. △T correlated with time constant, an index of LV relaxation, and with LV peak negative dp/dt obtained by catheterization (r=0.63, -0.65 respectively). There was significant prolongation of Iia-O in HCM, DCM and HT when compared to NOR (p<0.001, respectively). There was also significant prolongation of △T in HCM, DCM and HT (p<0.001, p<0.001, p<0.01, respectively). This suggests that in these groups, LV relaxation is prolonged and ACG downstroke falls more slowly during early relaxation than NOR. There was no significant difference in Iia-O but was significant difference in △T between ICM (HCM and DCM) and HT (p<0.05). These result suggests that ACG downstroke pattern from Iia of PCG to the O-point of ACG reflect LV relaxation in HCM DCM and HT.

[ISSN]0513-1731

[NCID]AN00243156