Acute Effects of Physical Exercise in Patients with Arrhythmogenic Cardiomyopathy Harbouring Plakophilin-2 Variants.

BACKGROUND: Despite the connection between physical exercise and arrhythmogenic right ventricular cardiomyopathy (ARVC), there is no data on the safety and suitability of exercise for patients. OBJECTIVE: To quantify the incidence and complexity of premature ventricular contractions (PVC) and cardiometabolic load during different exercises in ARVC patients with pathogenic plakophilin-2 variants. METHODS: Twenty-five participants with definite ARVC (9 female/16 male) performed different exercises while cardiorespiratory function was monitored. Resistance exercises included two-legged squats and unilateral biceps curls, while endurance exercise included walking and cycling at heart rate (HR) of 80, 100 and 120 bpm. Each activity was followed by 10 min of recovery. RESULTS: PVC burden more than doubled (p < 0.001) during the early recovery phase compared with the active exercise phases, as did the occurrence of ≥ 3 PVC morphologies (52 vs 84%, p = 0.03). Only unilateral biceps curls did not increase PVC burden compared with rest (p = 0.361). Resistance exercises combined lower cardiac load and arrhythmic burden for comparable effort levels. Exercise intensity classification showed large fluctuation, from "light" to "high intensity" for the same task, depending on the metric used. CONCLUSIONS: Early recovery monitoring is essential to properly assess the arrhythmic burden of exercise in PKP-2 ARVC. Small muscle mass exercises showed the lowest PVC burden and cardiac load - surrogate markers of arrhythmic risk and disease progression - and therefore offer a promising path for prescribing exercise in this population. Exercise intensity guidelines for ARVC are insufficiently clear and should be refined.