Structured Graphical Abstract.

Graphic depiction of new cardiac disease features demonstrated by this study (top left) with arrows to relevant analyses. Kaplan Meier survival analysis for the primary malignant ventricular arrhythmia endpoint during follow-up for male EMD and male LMNA variant-carriers with a baseline cardiac phenotype (top right). Cardiac disease features at last evaluation for male LMNA, male EMD and female EMD variant-carriers (bottom left). Violin plots comparing age at cardiac diagnosis for male EMD, female EMD and male LMNA variant-carriers (bottom right). Abbreviations: AF, atrial fibrillation; EDMD1, Emery–Dreifuss muscular dystrophy Type 1; ESHF, end-stage heart failure; LVSD, left ventricular systolic dysfunction; MVA, malignant ventricular arrhythmia; NSVT, non-sustained ventricular tachycardia.