A 24-year-old white male was referred to us in January 2019 for a second opinion due to recurrent syncope, related to physical activity. The patient was an amateur athlete, performing marathons and triathlons on a high-performance level and was trained in martial arts. In 2013, he suffered a traumatic brain injury caused by a syncope during physical activity. At this point, the syncope was explained by the high temperatures at that day and no further examinations were carried out. A year later, near drowning occurred during life guard training requiring short-term resuscitation by his colleagues. Following this incidence, the patient presented himself at a cardiologist for the first time. Routine diagnostic work-up including 12-lead ECG, echocardiography, and cardiac magnetic resonance imaging revealed no evidence of a structural heart disease or channelopathy. A genetic testing was not performed due to the patients’ reluctant attitude towards diagnostics. Due to the recurrent unexplained syncope, an ILR was inserted in the following. Since then, no syncope occurred, however, the ILR regularly recorded frequent PVC and one high-rate episode at 250 b.p.m., which was interpreted as supraventricular tachycardia. Despite recommendations to the contrary, he continued the ambitious sporting activity. In 2016, the patient requested the explantation of the ILR against the doctors advise because he reported abnormal sensations from it and he did not expect any further findings from it. Between 2016 and the first contact at our outpatient clinic, he was asymptomatic most of the time. At the time of his first presentation, he reported frequent palpitations. This was also the reason for his presentation at our clinic. A detailed family history revealed that his mother had been suffering from physical and emotional stress associated syncope for years. Furthermore, his maternal grandfather died of SCD at the age of 28, his two great uncles died at a young age. One died suddenly at the age of 17 while playing soccer, whereas the other one died of unknown cause in a mine. He presented himself in a very well-trained condition. Physical examination showed no abnormalities, the ECG showed a normal axis with regular intervals without any signs of pre-excitation or early repolarization (). Besides a mild mitral insufficiency, the echocardiography was inconspicuous. During exercise-ECG, he developed frequent PVCs at a resistance of 175 Watts (W), these PVC were predominantly polymorphic but also bidirectional. At a resistance of 250 W a significant drop of blood pressure (>20 mmHg) was noted and the patient reported dizziness, while he showed bidirectional bigemini and trigemini, but no sustained ventricular tachycardia (VT) (see ). The arrhythmias stopped immediately during recovery time. A genetic testing was performed which revealed a mutation in the cardiac RyR2-gene. Based on the clinical findings, the genetic blood test and the family history, the diagnosis CPVT was made. A therapy with betablockade was initiated but the patient tolerated only the minimal dosage due to significant sinus bradycardia. Furthermore, he planned to continue with physical activity on a high-performance level despite advice to the contrary. Therefore, we suggested to implant an implantable cardioverter-defibrillator (ICD) based on the history of recurrent syncope. The patient agreed to a single-chamber ICD implantation, which was performed in March 2020. The betablocker therapy was continued on the minimum dosage. Since then, no further episode of syncope or VT/ventricular fibrillation (VF) occurred. The RyR2 mutation was also detected in his mother and his sister. Since the sister also experienced exercise-related syncope in the meantime, ICD implantation was performed in both family members as well. depicts the family tree including the definite and suspected mutation carriers.