Unexplained Loss of Consciousness in a Patient With Klinefelter Syndrome and Brugada Syndrome.

Managing patients with both Klinefelter syndrome (KS) and Brugada syndrome (BrS) is challenging because of the rarity of this unique interaction. A man diagnosed with KS during fertility treatment experienced chronic muscle pain, severe depression, and cognitive difficulties, managed with testosterone therapy and antidepressants. Increased testosterone doses led to recurrent episodes of loss of consciousness, initially considered epileptic. Hormonal assessments, cardiac imaging, Holter monitoring, electrophysiological studies, and genetic testing led to BrS diagnosis. A positive ventricular tachycardia stimulation study led to the implantation of an implantable cardioverter-defibrillator. Following implantable cardioverter-defibrillator insertion, discontinuing testosterone, and changing medication, the patient has remained stable. The coexistence of KS and BrS is extremely rare. Understanding hormonal and genetic interactions in managing such complex cases is crucial.