LAUSR

OBJECTIVE To demonstrate that the analysis of the atrioventricular, intraventricular, and interventricular asynchrony by point-of-care ultrasound (POCUS) could be an alternative tool for assessing complex arrhythmias in pediatric patients with congenital heart diseases, mainly when an epicardial register or electrophysiology study is not available. DESIGN Descriptive, retrospective case series study. SETTING The pediatric intensive care unit of a university-affiliated tertiary hospital in Spain. PATIENTS The authors included 12 patients with congenital heart disease younger than 18 years admitted to the authors' pediatric intensive care unit (PICU) from January 2018 to December 2019, with complex arrhythmias after surgery, managed by performing a bedside echocardiography when an electrophysiology test or epicardial auriculogram was unavailable. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS The authors included a total of 14 complex arrhythmias in 12 postsurgical patients in whom a comprehensive transthoracic electrocardiogram was not conclusive. The presence of atrioventricular, intraventricular, or interventricular asynchrony was assessed in standard echo views by performing M-mode and Doppler mitral inflow analysis, checking the heart motion. The final POCUS diagnoses were atrial flutter (n = 5), postsurgical atrioventricular block (n = 4), asynchrony induced by pacemaker (n = 2), junctional ectopic tachycardia (n = 1), nodal rhythm plus ventricular extrasystole (n = 1), and supraventricular tachycardia (n = 1). In all patients, regardless of the type of arrhythmia, detecting motion asynchrony was crucial for making the correct diagnosis. Offline cardiologist analysis of the POCUS scans showed full agreement. CONCLUSIONS POCUS is a useful tool for initial diagnosis and management of complex arrhythmias in the PICU, mainly when epicardial auriculogram or electrophysiology studies are unavailable.