Combined Cardiac Impairments in End-Stage Renal Disease

Abstract

To the Editor,We were impresses by the article published in PediatricCardiology by Kobayashi et al. [1], The Impact of Changein Volume and Left-Ventricular Hypertrophy on Left-Ventricular Mechanical Dyssynchrony in Children WithEnd-Stage Renal Disease. The study provides an importantcontribution to the scarce data on functional/organic car-diac impairments in children with end-stage renal disease(ESRD).Kobayashi et al. detected left-ventricular dyssynchrony(LVD) using real-time three-dimensional echocardiogra-phy in children with ESRD undergoing renal replacementtherapy (peritoneal dialysis or hemodialysis). The authorsstated that dyssynchrony was significantly greater in ESRDchildren, especially those on hemodialysis therapy, com-pared with controls and improved after hemodialysis. Theauthors concluded that ESRD children presented volumeload and left-ventricular hypertrophy (LVH), which wereprobably associated with increased LVD. They assumedthat cardiac dyssynchrony could be an independent pre-dictor of serious cardiac events in patients with ESRD [1].Regarding cardiac impairments in such patients, wewould like to draw attention to our findings [2, 3] showingintraventricular conduction disturbances in ESRD childrenin whom no abnormalities were observed on 12-leadelectrocardiographic and echocardiographic examinations.In our study, a noninvasive multielectrode (87-lead) bodysurface potential mapping system (Fukuda Denshi Co Ltd,Tokyo, Japan) was applied to create isochrone maps toprecisely reflect a sequence of ventricular activation time(i.e., VAT maps).In our ESRD children treated conservatively [2] or withrenal replacement [3], abnormal maps with delayed VATvalues were noted, indicating some perturbations within theintraventricular conduction pathway. Patients on hemodi-alysis for\1 year demonstrated VAT maps typical for leftbundle branch block (LBBB), which was partially allevi-ated after renal transplantation, becoming left anteriorfascicle block. In children on hemodialysis for [1 year,VAT maps showed more serious disturbances in the formof complete LBBB that was normalized to incompleteLBBB due to kidney transplantation.According to Kobayashi et al. [1], disorders of electricalactivation, consequently leading to LVD, can occur inpatients with ESRD. Multifactoral damage of the ventric-ular myocardium probably causes spatiotemporal hetero-geneity and therefore LVD, which is additionally impairedby LVH. It is supposed that LVH can be a response ofthe myocardium to numerous ‘‘cross-talking networks’’appearing both as the result of ESRD and during renal-replacement therapy.Our findings [2, 3] suggest that disturbances of theintraventricular conduction system observed in childrenwith ESRD can be a significant component of LVD, whichinevitably leads to systolic left-ventricular dysfunction.