Unexplained syncope in a young athlete: the diagnostic process to find the diagnosis—a case report

BACKGROUND: Differential diagnosis of recurrent syncope is a routine procedure in clinical practice. Most of these syncopes are benign reflex syncopes but identifying patients with cardiac syncope is crucial to prevent fatal outcomes. CASE SUMMARY: In this case report, we present the case of a young athlete with recurrent unexplained syncope referred to us for a second opinion. Despite normal resting-electrocardiography and echocardiography, he developed frequent polymorphic and bidirectional premature ventricular contractions during exercise. Genetic testing confirmed a mutation in the RyR2-gene and the diagnosis of catecholaminergic polymorphic ventricular tachycardia was made. A medical therapy with betablockers was initiated but poorly tolerated, so that an implantable cardioverter-defibrillator was implanted. Furthermore, family screening revealed his mother and his sister to be genetic carriers as well. Implantable cardioverter-defibrillator implantation was performed in both family members. The patient did not experience any syncope or arrhythmic episodes during the follow-up period. DISCUSSION: This case report highlights the importance of thorough diagnostic and potential pitfalls in patients with unexplained syncope. Sometimes, the diagnostic steps need to be extended or repeated to detect rare or potential malignant causes of syncope.