De subitaneis mortibus. XXX. Observations on the pathophysiology of the long QT syndromes with special reference to the neuropathology of the heart.

Eight patients (different families) with syncopal attacks and a long QT interval in the ECG died suddenly. Five heard normally and three were born deaf. At postmortem examination of all eight hearts the single consistent abnormality was focal neuritis and neural degeneration within the sinus node, A-V node, His bundle and ventricular myocardium. Although the etiology of this intracardiac neural disease is uncertain, a chronic viral infection or some noninfectious degenerative process are among the plausible causes discussed. If intracardiac neuritis and neural degeneration prove to be a prevalent finding among other victims dying from the long QT syndromes, further consideration should be given to whether there is any genuine hereditary component in the pathogenesis. Because of the asymmetrical and focal distribution of the cardioneural lesions, the response to present forms of medical or surgical treatment of the lung QT syndromes may vary from benefit to harm. Until more is known of the true etiology of the neural disease, treatment will probably remain empirical in nature and should be conducted with cautious clinical observation.