Sudden cardiac death due to long QT syndrome

Identification of sudden cardiac death (SCD) with a structurally normal heart remains an important challenge in forensic pathology. Long QT syndrome (LQTS) is known as an inherited or acquired channelopathy, which is characterized with prolonged QT interval, and is likely to cause SCD in young adults. In this circumstance, no specific pathological change in the heart can be found anatomically or histologically in the LQTS victims. Thus, postmortem LQTS diagnosis is mainly based on clinical manifestations and genetic testing. Here, we reported a 26-year-old woman who was found dead at home with a history of unexplained syncope. Her clinical records and an electrocardiograph (ECG) obtained 3 months before her death showed a QTc interval of 539 ms which implicates the diagnosis of LQTS. Although the autopsy and pathological examination findings lacked specificity, we noticed enhanced lipofuscin accumulation in cardiomyocytes, which might be related to LQTS. After excluding potential diseases and injuries, we made the postmortem diagnosis as LQTS according to ECG, clinical history, and forensic postmortem findings. In conclusion, we provided clinical and pathological features of an SCD case due to LQTS, which might enrich the understanding of forensic postmortem SCD diagnosis with nonstructural cardiac diseases.