INTRODUCTION/AIMS It is unclear whether the heart is affected in pediatric patients with milder forms of spinal muscular atrophy (SMA). Therefore, we aimed to determine the presence of any cardiac abnormalities in these patients. METHODS We conducted a cross-sectional study of children and adolescents with SMA types 2 and 3 between July 2018 and July 2019. All patients underwent a comprehensive cardiac evaluation, including history taking, physical examination, electrocardiography, echocardiography, measurement of cardiac biomarkers (cardiac troponin T (cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP)), and 24-hour Holter monitoring. RESULTS In total, 42 patients were enrolled (27 and 15 with SMA type 2 and 3, respectively). No patient had structural heart disease except for one with mitral valve prolapse. None had signs of ventricular dysfunction on echocardiography. Both cTnT and NT-proBNP levels were normal in all patients. ECG showed sinus tachycardia in 7 patients (16.7%), and prolonged PR interval in one (2.4%). Holter monitoring detected benign ventricular arrhythmias in 2 patients (4.8%), and rare supraventricular premature beats in one. The mean 24-hour heart rate was elevated in 6 patients (14.3%), while both the minimum 24-hour heart rate and the maximum RR interval were increased in 23 (54.8%). DISCUSSION The prevalence of cardiac disease in pediatric patients with SMA types 2 and 3 is low; however, these patients might have increased resting heart rates. A complete cardiac history and physical examination are a useful screen. Additional cardiac investigations may be performed as needed. This article is protected by copyright. All rights reserved.
Cardiac findings in pediatric patients with spinal muscular atrophy types 2 and 3.