CONGRESS ABSTRACT

Left Ventricular Hypertrabeculation (LVHT) is a myocardial disorder characterized by abnormal trabeculations in the left ventricular lumen and deep intertrabecular recesses; this phenotypic trait can occur either in isolation or in association with other conditions, such as left ventricular hypertrophy, dilation, systolic/diastolic dysfunction or congenital heart defects. In recent decades, the incidence of LVHT has considerably increased due to higher sensitivity of advanced imaging techniques, both echocardiography and cardiac magnetic resonance (CMR). Clinical manifestations in LVHT vary greatly: from no symptoms to severe heart failure, arrhythmias, sudden cardiac death (SCD) or thromboembolic events. Aim of this study was describing arrhythmic manifestations of pediatric patients with LVHT who needed cardiac devices implantation (PMK or ICD) during follow-up. From 2013 we enrolled 140 pediatric patients with LVHT followed at our Institution. Data regarding family history, instrumental exams, cardiac magnetic resonance, genetic testing were collected. Most of them had isolated LVHT (80.7%); in other patients, mixed phenotypes (hypertrophic or dilated cardiomyopathy or congenital heart disease) were present. Arrhythmias were found in 33 children (23.6%) during a mean follow-up of 51 ±19 months. Two patients showed complete atrio-ventricular block and were implanted with a transvenous PMK in one case and an epicardial system in the other one. Three patients received an ICD. In one patient there was a primary prevention of SCD indication because of symptomatic not-sustained and sustained ventricular tachycardias; the other 2 cases were ICD implantations for secondary prevention of SCD in patients with history of resuscitated cardiac arrest.  As regard genetic results patients who received a pacemaker had no relevant genetic mutations (only VoUS variants according to ACMG); in 3 patients with tachyarrhythmias and ICD implanted genetic results were positive for mutations likely pathogenic or pathogenic in genes PRDM16 (class 4), LMNA (class 5), NDUFA1 (class 4). In conclusion in our pediatric cohort with LVHT arrhythmias were not so rare (23.6%). Furthermore in about 3% of cases a cardiac implantable device was needed to prevent SCD. Genetic testing can help to stratify arrhythmic risk in patients with ventricular arrhythmias.