This report describes an unusual case of secondary nocturnal enuresis presumptively secondary to progressive bradycardia from complete heart block. Congenital complete heart block occurs in approximately 1 of 22 000 livebirths and is typically associated with structural congenital heart disease or maternal collagen vascular diseases.6 It can be entirely asymptomatic during infancy and childhood, depending in part on the escape rate and rhythm and other hemodynamic variables. The case described above was not diagnosed until the patient coincidentally underwent cardiac monitoring. The picture was confusing initially, as a tricyclic antidepressant medication had been ingested. Heart block is one of the known cardiovascular effects of tricyclic antidepressant overdose.7 However, the conduction disturbance should have resolved as the drug was excreted from the body. As children with congenital complete heart block get older, the ventricular escape rate typically decreases. In addition, as activity increases with age, more demand is placed for cardiac output. The resting end-diastolic volume is increased to elevate stroke volume in compensation for lower heart rate. As the escape rate decreases and the metabolic demand increases, patients with congenital complete heart block then may begin to develop symptoms. Typical symptoms in children include dizzyness, Stokes-Adams syncopal attacks, fatigue, daytime somnolence, and other somatic complaints.8 Bed-wetting has not been reported as an initial symptom, but in this case is likely secondary to the excessive somnolence and difficulty with arousal. Although congenital complete heart block is not the first diagnosis to consider in the patient with secondary nocturnal enuresis, and cardiac pacemaker implantation is generally not the treatment of choice for bed-wetting, in this particular patient, we felt that imipramine would not have been a wise choice for therapy of enuresis.
- Received December 17, 1992.
- Accepted February 17, 1993.
- Copyright © 1993 by the American Academy of Pediatrics