P738evidence of the non compensatory nature of left ventricular hypertrophy in the pediatric transplanted heart: a speckle tracking study.


    loading  Checking for direct PDF access through Ovid

Abstract

Introduction: Increase in left ventricular (LV) mass represents a compensatory mechanism aimed at preserving cardiac function in the presence of increased workload. However, in cardiac transplanted (c-Tx) adult patients, increased LV mass has been shown to be strongly associated with unfavorable outcome even in the absence of clear-cut LV hypertrophy. Thus, LV mass increase in c-TX might represent a frankly pathological phenomenon. No data are available on the relation between LV mass and advanced indices of LV systolic function in c-Tx pediatric patients.Methods: 55 c-Tx patients and 10 healthy volunteers underwent standard 2 dimensional echocardiographic examination with speckle tracking (STE) analysis (iE33, Philips,Andover, MA, USA). Base and apical LV rotation were analyzed in parasternal short axis view. The difference between the apical clockwise rotation and the basal counterclockwise rotation of the LV was computed to derive LV twist (expressed in °) and torsion (expressed in ° per cm of LV length). Regression analysis was performed in c-Tx as well as in the control group to identify possible differences.Results: Patients with evidence of acute rejection, established coronary artery occlusion, EF< 55%, inadequate echocardiographic images and/or with transplant performed less than 4 months before the echocardiogram were excluded. Analysis was thus available in 25 c-Tx. Mean time from heart transplant was 5.8 years. No differences were observed among groups in LV ejection fraction (66% vs 67%; p=ns). Both LV twist and torsion were reduced in c-Tx as compared to normals (1.11°/cm vs 0.77°/cm; p<0.01). In multiple regression analysis - controlling for LV ejection fraction and age - while in healthy volunteers no impact of LV mass was observed on LV function (p=ns), a strong significant negative association was found in c-TX, suggesting that increased LV mass negatively impacts both LV twist (Beta=-0.66; r=0.72; p<0.01) and torsion (Beta=-0.61; r=0.77; p<0.01), despite preserved ejection fraction. Findings were confirmed also when excluding patients with clear-cut LV hypertrophy (n=6).Conclusions: In c-Tx pediatric patients, despite normal EF, a significant impairment in LV twist and torsion is found. The reduction in advanced parameters of global LV systolic function is linked to an increase in LV mass. Our data suggest that in children with c-Tx increased LV mass represents a frankly pathological phenomenon, affecting LV function, also in the absence of clear-cut ventricular hypertrophy.

    loading  Loading Related Articles