Uncovering Electromechanical Uncoupling in Subclinical Pathogenic Mutation Carriers and Arrhythmogenic Cardiomyopathy Patients

Abstract

Arrhythmogenic cardiomyopathy (ACM) is a progressive inherited heart disease. The clinical presentation of ACM is heterogenous and diagnosis remains challenging. Whereas echocardiographic deformation imaging was capable in detecting subtle functional abnormalities in asymptomatic ACM patients, the 12-lead electrocardiogram (ECG) is still not able to detect these subtle electrical changes. As the 12-lead ECG might not be sensitive enough, this study aimed to relate the electrical changes as recorded by body surface potential mapping (BSPM) to the mechanical changes detected by echocardiographic deformation imaging. Per lead, the integral values of all 67 leads were calculated per 5 ms intervals during ventricular depolarization and the lead in which the absolute minimum appeared the most $(lead_{min})$ was identified. The direction of this vector towards a specific heart segment was then compared to the interval between QRS onset and local onset of myocardial shortening, the electromechanical interval (EMI). We observed a relation $of\ {lead_{min}}$ pointing towards the basal segment of the right ventricle $(RV_{basal})$ and an increased EMI in this area suggesting the existence of an electromechanical relationship in $RV_{basal}$,, With this study, the first steps towards relating both electrical and mechanical changes in ACM pathogenic mutation carriers is made.