P904Heart rhythm and conduction disorders in children with restrictive cardiomyopathy

Abstract

Abstract Introduction Restrictive cardiomyopathy (RCMP) is characterized by restrictive filling and reduced diastolic volume of either or both ventricles with normal or near-normal systolic function and wall thickness. It may occur idiopathically or as a cardiac manifestation of systemic diseases and various neuromuscular disorders. Often RCMP occurs with severe symptoms of heart failure and has an poor prognosis. Given the presence of structural myocardial abnormalities, atrial dilatation, this group of patients has a high risk of heart rhythm and conduction disturbances. Objective To present our clinical experience in RCMP with the heart rhythm and conduction disturbances in children. Material and methods The study was approved by the Institute Ethical Review Board. On behalf of the children enrolled in the study, written informed consent was obtained from the next of kin. The study included 18 children with RCMP presented with heart failure class II-IV. The genotyping was performed to all patients. The identified genetic variants were classified according to ACMG guidelines. We analyzed clinical history, data of physical examination, laboratory findings, ECG, echocardiography, Holter monitoring, genetic test, cardiac MRI and CT performed according to clinical indications and physician's. Results Mean age of RCMP manifestation was 2,1 y.o. [0–11] with HF as a main clinical feature. Rhythm and conduction disorders were reported in 83% (n=15) of children. The structure of the disorders included: atriventricular block 1–2 degrees in 22% (n=4), supraventricular disorders (extrasystole, tachycardia, atrial fibrillation) in 44% (n=8), ventricular disorders (extrasystole, tachycardia) in 16% of patients (n=3). One patient had a combined rhythm and conduction disorder (sinus sick syndrome, atrial fibrillation, supraventricular and ventricular tachycardia), which required implantation of a pacemaker with a defibrillator function. In one patient, the manifestation of the disease was with hemodynamically significant permanent-recurrent atrial tachycardia. Mortality in this group of patients was 27% (= 5), the cause of death was the progression of heart failure in 3 children and sudden arrhythmial death in 2 patients. Conclusions Thus, RCMP is a severe, genetically caused, with early manifestation progressive disease with high risks of rhythm and conduction disturbances, sudden arrhythmial death. According to the testimony, patients should receive antiarrhythmic therapy and, if necessary, pacemaker implantation is indicated.