Mechanical and electrical uncoupling: the role of cardiac magnetic resonance imaging in arrhythmogenic cardiomyopathy. Proof of concept

Jorge A. Ortega-Hernández, Clinical Cardiology, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad De México, México
Mario R. García-Arias, Clinical Cardiology, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad De México, México
Jardiel Argüello-Bolaños, Clinical Cardiology, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad De México, México
Manlio F. Márquez-Murillo, Research Division, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad De México, México
Rodrigo Gopar-Nieto, Unidad Coronaria, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, México
Ángel A. Priego-Ranero, Clinical Cardiology, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad De México, México
Daniel Sierra-Lara-Martínez, Coronary Care Unit, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad De México, México

Objectives: Arrhythmogenic cardiomyopathy (ACM) is a complex cardiac disorder associated with ventricular arrhythmias. Understanding the relationship between mechanical uncoupling and cardiac structural changes in ACM patients is crucial for improved risk stratification and management. Methods: In this study, we enrolled 25 ACM patients (median age 34 years, 72% men) based on the 2019 Modified Task Force and Padua criteria. Patients were categorized by the presence or absence of clinically relevant ventricular tachycardia (crVT), necessitating emergency interventions. Right ventricular-arterial coupling (VAC) was assessed using echocardiography. Low-rank regression splines were employed to model left ventricular ejection fraction (LVEF) and right ventricular ejection fraction (RVEF) in relation to VAC. Results: Positive associations were observed between VAC and LVEF (ρ = 0.472, p = 0.023), RVEF (ρ = 0.522, p = 0.038), and right ventricular (RV) indexed stroke volume (ρ = 0.79, p < 0.001). Patients with crVT exhibited correlations with RV shortening, reduced RVEF (39.6 vs. 32.2%, p = 0.025), increased left ventricular (LV) mass (38.99 vs. 45.55, p = 0.045), and LV end-diastolic volume (LVEDV) (56.99 vs. 68.15 mL/m2, p = 0.045). Positive associations for VAC were noted with LVEDV (p = 0.039) and LV mass (p = 0.039), while negative correlations were observed with RVEF by CMR (p = 0.023) and RV shortening by echocardiography (p = 0.026). Conclusions: Our findings underscore the significance of right VAC in ACM, demonstrating correlations with RV and LVEF, RV stroke volume, and clinically relevant arrhythmias. Insights into RVEF, LV mass, and end-diastolic volume provide valuable contributions to the understanding of ACM pathophysiology and may inform risk assessment strategies.

Keywords: Arrhythmogenic cardiomyopathy. Right ventricular-arterial coupling. Ventricular tachycardia. Echocardiography.