Cardiac conduction disturbance detected in a pediatric population.

OBJECTIVE: To delineate the prevalence and clinical implications of cardiac conduction disturbance (CCD) in school-age children. STUDY DESIGN: Between 1999 and 2001, a citywide survey of 432,166 elementary and high school students had been performed in Taipei by questionnaire, electrocardiography, phonocardiography, and physical examination. Patients with any abnormalities on this survey were referred for final diagnosis. RESULTS: After excluding those with congenital heart disease (CHD), the prevalence of CCD was 0.75%, higher in males than in females (0.78% vs 0.71%). Incomplete right bundle branch block (IRBBB; 0.32%), complete right bundle branch block (CRBBB; 0.11%), ventricular premature contraction (0.11%), and Wolff-Parkinson-White syndrome (0.067 %) were the most common diagnoses. Second-degree atrioventricular block, IRBBB, CRBBB, and intraventricular conduction delay were more common in males; and atrial premature contraction was more common in females. The prevalence of CCD increased with age, from 0.48% in elementary school students to 0.97% in high school students. After detection of CCD, 39 patients with previously undiagnosed atrial septal defect (ASD) and 15 high-risk patients were found. The sensitivity of IRBBB in screening for ASD was 34.67%. CONCLUSIONS: The prevalence of CCD in children without CHD was 0.75%. Detection of CCD helped identify patients with unrecognized ASD and high-risk cardiac patients.

Noninvasive diagnosis of aortic coarctation in neonates with patent ductus arteriosus.

OBJECTIVES: To find a noninvasive method to detect coarctation of the aorta (CoA) in the presence of a patent ductus arteriosus (PDA) in neonates. STUDY DESIGN: From 1994 to 1998, 36 neonates with CoA and PDA confirmed by surgery or cardiac catheterization were studied; another 19 neonates with isolated PDA served as control patients. The prospective study was conducted from 2001 to 2002 on 162 neonates. RESULTS: Among the 36 neonates in the CoA group, 14 patients (39%) had blood pressure discrepancy, 26 patients (72%) had a visualized posterior shelf by echocardiogram, and the ratio of isthmus/descending aorta diameters (I/D ratio) was below 0.64 in 32 patients (89%). None of the control patients had these features. A diagnostic approach was subsequently proposed, according to which a neonate with PDA who fulfilled any of the above features was diagnosed as CoA plus PDA. In the prospective study, the sensitivity and positive predictive values of this method were both 91.7%, whereas the specificity and negative predictive values were both 99.3%. CONCLUSIONS: Echocardiographic measurements of I/D ratio along with the delineation of posterior shelf and a BP discrepancy can satisfactorily identify CoA in the presence of PDA in neonates.