1 Department of Pediatric Cardiology, Cook County Hospital and the Department of Pediatrics, University of Illinois College of Medicine, Chicago
Acceleration of the nodal pacemaker can occur in children as a result of inflammation, drug toxicity, or trauma. The rapid nodal rate leads to A-V dissociation which may persist for days. In acute rheumatic fever a persistent nodal rate in excess of 80 per minute seems to be a highly specific indication of carditis often preceding other evidence of cardiac involvement. This arrhythmia is frequently seen after cardiac surgery, particularly when the atrial or the ventricular septum is the site of the operation. An accelerated nodal pacemaker can also occur due to digitalis toxicity. Hypokalemia appears to make children with congenital heart disease more susceptible to this arrhythmia. The A-V dissociation caused by an accelerated nodal pacemaker must be differentiated from the A-V dissociation seen in normal children with sinus arrhythmia. The cardiac surgeon should recognize that, although there may be complete A-V dissociation, he can separate this entity from surgically induced heart block because the nodal rate is over 80 per minute.
Submitted on July 1, 1968