Precordial leads QRST time integrals for evaluation of right ventricular overload in children with congenital heart diseases

The poor performance of RSR' pattern on electrocardiogram lead V1 for detection of secundum atrial septal defects in children

OBJECTIVE

To assess the accuracy of RSR' patterns in lead V1 (RSR'-V1) in diagnosing atrial septal defects (ASDs) in children.

STUDY DESIGN

Children who underwent an electrocardiogram (ECG) during 2010 were divided into 2 ECG groups: RSR'-V1 and normal (no RSR'-V1). Children who underwent an echocardiogram during 2010 were also divided into an ASD group and a normal echocardiogram group. The 4 groups were matched in a 2 × 2 table format where the RSR'-V1 was the "test" and ASD was the "disease." Sensitivity, specificity, positive/negative predictive values, and pre/post-test probabilities were calculated.

RESULTS

There were 4658 ECG studies included in the analysis: 836 had RSR'-V1 and 3822 were normal without RSR'-V1. Of 4935 echocardiographic studies analyzed, 329 had an ASD and 4606 were normal; 1363 patients had both studies done during the study period. The ECG sensitivity for diagnosing an ASD was 36.1%, specificity was 80%, positive predictive value was 14.7%, and negative predictive value was 92.9% with an overall accuracy of 76.2%. Patients with ASD and RSR'-V1 were significantly older than patients with ASD and no RSR'-V1 pattern.

CONCLUSION

RSR'-V1 is a poor screening test for the detection of ASD. It should not change the clinical suspicion or the decision to obtain an echocardiogram. Older children without RSR'-V1 on ECG are unlikely to have an ASD.

Analysis of T wave changes by activation recovery interval in patients with atrial septal defect

We examined the distributions of the activation recovery interval (ARI), which is correlated with the local action potential duration (APD), to clarify the origin of the repolarization changes in ASD. The ECGs, QRST isointegral maps and ARI isochronal maps of 21 children with ASD from 3 to 5 years old in age were studied in comparison with 21 age-matched normal children. A conventional and 87 unipolar body surface ECG were simultaneously recorded. The ARIs were determined from the first derivatives of the ECG waveforms. Abnormal ST-T patterns were observed in 11 of 21 ASD, but only in two normal children. The QRST maps of a split positive area pattern were seen in 15 of ASD but none of the normal. In the ARI maps, all the normal children exhibited a short-ARI area on the left and a long-ARI area on the right side of the chest. In 19 of ASD, the ARI distribution revealed a leftward extension of the long-ARI area on the anterior chest, a relative shortening on the right anterior chest, and a localized prolonged ARI on the left anterior chest. The results suggest that right ventricular (RV) volume overload in ASD produces a localized prolongation of the APD on the RV epicardium.