ABSTRACT
<p><b>BACKGROUND</b>Incomplete right bundle branch block (ICRBBB) is commonly associated with atrial septal defect (ASD), but lacks sufficient diagnostic test characteristics. An abnormal T wave is also often observed in ASD, with horizontal or inverted displacement of the proximal T wave limb in the right precordial leads, termed "defective T wave" (DTW).</p><p><b>METHODS</b>We examined the diagnostic test characteristics of combining ICRBBB with DTW as a new index to diagnose ASD. A total of 132 consecutive patients with ASD and 132 cases of age/gender-matched controls without ASD were enrolled.</p><p><b>RESULTS</b>Sensitivities of DTW, ICRBBB, and both were 87.1% - 87.9%. Specificities were 97.0%, 96.2%, and 100%, respectively. Positive predictive values were 1.3%, 1.1%, and 100.0% respectively, while negative predictive values were 99.9% for each.</p><p><b>CONCLUSION</b>Combining ICRBBB with DTW in electrocardiogram (ECG) as a new index significantly increased the specificity and positive predictive values while maintaining a high sensitivity in diagnosing ASD.</p>