The crochetage pattern in electrocardiograms of pediatric atrial septal defect patients

OBJECTIVES: To test the sensitivity and specificity of the crochetage patte rn (a notch near the apex of the R wave in electrocardiographic inferior li mb leads) in the pediatric electrocardiogram for detecting patients with a secundum atrial septal defect. PATIENTS AND METHODS: Electrocardiograms from 82 consecutive preoperative p ediatric patients with a secundum atrial septal defect confirmed by two-dim ensional echocardiography were reviewed for evidence of right ventricular h ypertrophy and the crochetage pattern. These electrocardiograms were compar ed with 244 consecutive preoperative controls consisting of patients with e chocardiographically proven patent foramen ovale, ventricular septal defect , pulmonary stenosis, tetralogy of Fallot and patients with normal echocard iogram studies. RESULTS: The electrocardiographic crochetage pattern was observed in 31.7% of preoperative patients with a secundum atrial septal defect in at least o ne inferior limb lead. The specificity of the crochetage pattern for the de tection of a secundum atrial septal defect was high when present in all thr ee inferior limb leads (greater than 92%). The crochetage pattern in at lea st one lead in secundum atrial septal defects shows no association with inc omplete right bundle branch block (chi (2)(1)=0.80, not significant), and t hus these two findings together do not improve the detection of an atrial s eptal defect. CONCLUSIONS: The sensitivity and specificity of the electrocardiographic cr ochetage patterns in at least one inferior limb lead in echocardiographical ly proven secundum atrial septal defects are 31.7% and 86.1%, respectively. The electrocardiographic crochetage or notching pattern in inferior limb l eads has a high specificity for atrial septal defects in the pediatric popu lation.