ECHOCARDIOGRAPHIC MEASUREMENT OF PEAK RATES OF LEFT VENTRICULAR WALL MOTION IN CHILDREN

Abstract

To evaluate their usefulness as indices of left ventricular(LV) function, the peak rate of change of LV diameter (ΔD/Δt) was determined in 62 normal children (N) and 15 with congestive cardiomyopathy (CCM). From digitized echocardlograms of the septum and LV posterior wall, continuous plots of LV diameter were generated and the peak ΔD/Δt computed. The peak shortening rate (PSR) and peak relaxation rate (PRR) were determined in each subject and compared to conventional echocardiographic indices of LV function: % change in LV diameter (%ΔLVD) and mean velocity of circumferential fiber shortening (Vcf).In N, PSR was directly proportional (r = 0.70) to LV end-diastolic diameter (EDD) and when Indexed for EDD, PSR was directly related (r = 0.48) to heart rate (HR). but not to age (r = -0.17). The PRR was not related to EDD, HR or age. In CCM, PRS/EDD was de-creased(0.90 ± 0.42 SD vs 2.2 ± 0.54 in N, p< 0.001), and 13/15 pts were more than 2 SD below normal. The PRR was also reduced in CCM (42.22 ± 21.22 mm/sec vs 84.60 ± 32.88 mm/sec in N, p< 0.001), although PRR was within 2 SD of normal in 14/15 patients. All pts with CCM had decreased %ΔLVD and Vcf.This study Indicates that echocardiographically determined peak rates of LV wall motion are related to EDD and, to a lesser extent, HR. When corrected for these variables, PSR and PRR are decreased in pts with CCM.