A regular, wide QRS tachycardia was electrocardiographically documented in 32 patients aged 1 month to 18 years. The mechanisms of the tachycardia were evaluated using standard multicatheter electrophysiologic techniques. These mechanisms included (1) orthodromic reciprocating tachycardia with bundle branch aberration (seven patients), (2) antidromic reciprocating tachycardia using single (three patients), or multiple (three patients) atrioventricular connections (Kent bundles), (3) atrial flutter with ventricular preexcitation over accessory connections (eight patients), (4) reciprocating tachycardia using a nodoventricular connection (Mahaim fiber) (five patients), and (5) ventricular tachycardia (six patients). Regular, wide QRS tachycardias are not rare in pediatric patients. Their mechanisms can be quite complex, and electrocardiographic analysis with respect to QRS configuration, heart rate, or the presence or absence of ventriculoatrial dissociation is not sufficient for diagnostic purposes. Our results show that considerable understanding of the mechanism of regular, wide QRS tachycardias can be obtained by multicatheter electrophysiologic study. Understanding the mechanism is essential in order to make rational use of available therapeutic options.
Bibliographical noteFunding Information:
From the Departments of Pediatrics and Medicine, Duke University Medical Center, Durham, North Carolina. This study was supported in part by U.S. Public Health Service Grants HL-11307, HL-15190, HL-05716 and HL-07101. Dr. Gallagher is the recipient of an Established Investigatorship Award from the American Heart Association, Dallas, Texas. Manuscript received July 8, 1972; revised manuscript received November 16, 1981, accepted November 24, 1981.
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