Dilated cardiomyopathy masquerading as long QT syndrome.
Atrioventricular block has been described in association with cases of long QT syndrome and mortality is increased in this subgroup. We describe an infant with congenital QT prolongation and atrioventricular block with normal cardiac function, leading to the initial diagnosis of long QT syndrome. She subsequently developed dilated cardiomyopathy requiring cardiac transplantation. We postulate that the presenting electrocardiograph abnormalities were early manifestations of the myocardial disease, preceding the development of myocardial dysfunction by several months. The need for heightened surveillance in cases of QT prolongation with atrioventricular block is amplified by the possibility of an evolving cardiomyopathy.
Walls
J
J
Division of Cardiology, British Columibia Children's Hospital, Children's Heart Centre, 4480 Oak Street Vancouver, British Columbia, V6H 3V4, Canada.
Dipchand
A
A
Division of Cardiology, The Hospital for Sick Children, 555 University Ave, Toronto, ON, M5G 1X8, Canada.
Sanatani
S
S
Division of Cardiology, British Columibia Children's Hospital, Children's Heart Centre, 4480 Oak Street Vancouver, British Columbia, V6H 3V4, Canada. ssanatani@cw.bc.ca.
D000328:Adult; D001919:Bradycardia / Q000151:congenital / Q000175:diagnosis / Q000628:therapy; D002311:Cardiomyopathy, Dilated / Q000151:congenital* / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D004452:Echocardiography; D004719:Endomyocardial Fibrosis / Q000151:congenital / Q000175:diagnosis / Q000473:pathology; D004868:Equipment Failure; D005260:Female; D006327:Heart Block / Q000151:congenital* / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D006333:Heart Failure / Q000151:congenital / Q000175:diagnosis / Q000473:pathology / Q000628:therapy; D006340:Heart Rate, Fetal / Q000502:physiology; D016027:Heart Transplantation; D006801:Humans; D007231:Infant, Newborn; D008133:Long QT Syndrome / Q000151:congenital* / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D009206:Myocardium / Q000473:pathology; D010138:Pacemaker, Artificial; D011247:Pregnancy; D011296:Prenatal Diagnosis; D016171:Torsades de Pointes / Q000151:congenital / Q000175:diagnosis / Q000473:pathology / Q000628:therapy