First episode of ventricular fibrillation in an 84-year-old man with long-QT type 2 syndrome: A case report

Abstract

Congenital long QT syndrome (LQTS) is associated with ventricular arrhythmia and an increased risk of sudden cardiac death in young people. However, it is extremely rare for an elderly man to experience ventricular fibrillation (VF) due to congenital LQTS as a first episode. We describe the case of an 84-year-old man who experienced syncope after urination. He had a medical history of hypertension and asthma, but no history of syncope. Electrocardiographic findings in 2017 showed QT prolongation (corrected QT = 505 ms). No medication that could induce QT prolongation was administered. Blood test results on admission showed no electrolyte abnormalities, and there were no abnormal findings on echocardiography. The second episode of loss of consciousness occurred during hospitalization, and electrocardiography revealed incessant torsade de pointes, caused by R-on-T with short-long-short (SLS) sequences due to bradyarrhythmia. Coronary angiography did not detect myocardial ischemia, and an implantable cardioverter-defibrillator was implanted for secondary prevention. Genetic testing revealed a mutation of the KCNH2 gene, indicating LQTS type 2. In summary, we report a rare case of prolonged QT interval with SLS sequences due to sick sinus syndrome triggering VF as the first attack in an elderly patient with LQTS type 2.<Learning objective: Physicians should be aware of the prolongation of QT as a cause of syncope in elderly patients and should pay attention to QT duration. Furthermore, patients with elderly-onset QT prolongation may have a genetic background associated with congenital long QT syndrome (LQTS); therefore, we should not hesitate to perform genetic testing in cases where LQTS is suspected in elderly patients.>