ABSTRACT
A family with the heritable syndrome of prolonged Q-T interval is reported. Three members died suddenly. Six had a prolonged Q-T interval. One had syncopal episodes for four years but has had no syncope since therapy with propranolol was initiated two years ago. The inheritance appears to be autosomal dominant. There was no evidence of hearing defects. Histologic and electron microscopic studies were performed on cardiac tissue from one patient. This is the first report of electron microscopic studies, and the findings suggest a possible defect of calcium metabolism in the myofiber.
Subject(s)
Arrhythmias, Cardiac/genetics , Death, Sudden , Syncope/genetics , Adolescent , Arrhythmias, Cardiac/drug therapy , Arrhythmias, Cardiac/etiology , Arrhythmias, Cardiac/pathology , Electrocardiography , Genes, Dominant , Humans , Male , Mitochondria, Muscle/ultrastructure , Myocardium/pathology , Myocardium/ultrastructure , Myofibrils/ultrastructure , SyndromeABSTRACT
A pathologic study of the cardiac conduction system was performed in 57 patients who died within 30 days after aortic valvular replacement. Histologically, there were old and recent lesions present in 34 (60 percent) and 43 (75 percent) of the patients, respectively. Old lesions did not show meaningful correlation with preoperative electrocardiograms. Although nontraumatic recent lesions were rarely the cause of postoperative abnormal cardiac conduction, traumatic lesions were frequently associated with loss of sinus mechanism. The main cause of trauma to the major cardiac conduction tissue was injury by sutures. The short membranous septum predisposed to injury, while the configuration of the left ventricular outflow tract was not a significant factor in injury. Traumatic lesions of the cardiac conduction tissue were more common in subjects with bicuspid than tricuspid aortic valves.
