Role of electrocardiogram in detecting congenital heart disease:prevalence and diagnostic accuracy of pathognomonic features

Background and aims: Congenital heart diseases (CHD) account for a major portion of congenital anomalies. Certain electrocardiogram (ECG) features have been described as pathognomonic for some CHDs, over years. If ECG can be used as a screening tool, it would prompt detection of CHDs in resource-limited areas. However, comprehensive research on ECG's diagnostic accuracy is required before embarking on such a venture. Methods: This study, conducted in a tertiary care centre of Eastern India, aims to find out actual percentage prevalence of classical ECG features in different CHDs, and therefore, to assess diagnostic accuracy of the said ECG pointers (Fig. 1: graphical abstract). Results: Significant variation in ECG findings was noted across different CHDs; some like right axis deviation in TOF showed 100% prevalence and sensitivity, while others, like leftward P axis in sinus venosus ASD, were much less common. Many ECG features were highly specific, such as 100% specific Katz-Wachtel phenomenon in post-tricuspid shunts. Also, high diagnostic accuracy of ECG was demonstrated across several CHDs; 100% accuracy for tall monophasic R in V1 in severe PS, and high accuracy (> 95%) for PR prolongation and extreme axis deviations in AVSD and Ebstein’s anomaly. Overall, ECG parameters had high specificity and accuracy but varied in sensitivity, with combinations of specific and sensitive features proving effective for diagnosis in specific CHDs. Conclusions: A combination of specific ECG features, along with simple clinical tools can effectively screen for common CHDs, guiding early referral to cardiology service, especially in areas with limited access to advanced diagnostic tools like echocardiography.