Consultation withthe Specialist

Abstract

The pediatrician often is challenged to diagnose a child who has either an abnormally fast or slow heart rate. The initial investigation and management of supraventricular and ventricular dysrhythmias in childhood should be the domain of the primary pediatrician. However, the pediatrician must be aware of the etiologies, benign and malignant, and the potential dangers associated with various medical and electrical therapies. Presentation The presentation of dysrhythmia can vary from asymptomatic to congestive heart failure or even complete cardiovascular collapse. At times, the diagnosis is straightforward and readily obtained from the electrocardiogram (ECG). However, investigation involving 24-hour electrocardiographic recording or event monitoring may be required. The infant who presents for evaluation following 1 or 2 days of decreased feeding, irritability, and abnormal breathing accompanied by a documented heart rate in the office of 280 beats/min usually is not a diagnostic dilemma. When supraventricular tachycardia (SVT) persists for more than 24 hours, there may be associated physical findings, including hepatomegaly, pulmonary rales, and facial or sacral edema. On the other hand, an infant may present having a similar heart rate without symptoms, especially when the SVT has been intermittent or of relatively short duration. Toddlers and younger children may have a change in behavior during the event.