Too old for a life-threatening inherited cardiac condition? The importance of cascade genetic testing

Introduction CPVT is a rare inherited channelopathy which predisposes patients to malignant ventricular arrhythmias during exercise or stress. Although exceptionally rare, the diagnosis can be made in individuals over 40 years. Case presentation A 58-year-old male with persistent atrial fibrillation was evaluated for exercise prescription. He was keen on low-intensity skill sports and medium-intensity endurance sports. He reported no symptoms and had no relevant family history. The ECG showed atrial fibrillation without other abnormalities. The transthoracic echocardiogram demonstrated severe left atrial dilatation but nothing else of note. The exercise test revealed a poorly controlled ventricular rate with effort, with frequent monomorphic PVC and a 4-beat NSVT. The CTCA and CMR excluded significant coronary artery disease or an underlying cardiomyopathy. The bisoprolol dose was increased, and the patient was advised to limit his training to moderate-intensity exercise. In the meantime, the patient’s 25-year-old daughter suffered a sudden cardiac arrest and was found to harbor a pathogenic RYR2 mutation, later identified in our patient through predictive genetic testing. The patient was reassessed considering the genetic result. An exercise test revealed bi-directional PVCs. He was switched on a non-selective beta-blocker. Specific exercise prescription and lifestyle changes were discussed. Conclusion Genetic testing in CPVT is crucial for diagnosis and prognosis of affected individuals, as well as for identifying family members at risk, even in the absence of a characteristic phenotype.