Left Atrial size assessment on ECG in patients with Mitral Stenosis using P Wave parameters and taking Transthoracic Echo as Gold Standard

Abstract

BACKGROUND:  Left atrial enlargement (LAE) is a key indicator of cardiovascular risk, including atrial fibrillation and stroke. While transthoracic echocardiography (TTE) is the gold standard for measuring LA size, electrocardiography (ECG) provides a simpler, non-invasive screening option. So, aim of the study is to evaluate the diagnostic accuracy and correlation between left atrial enlargement characteristics on ECG (P-wave) and the severity of mitral stenosis, as assessed by left atrial diameter measurements obtained through transthoracic echocardiography (TTE).

Objective: To assess the Left Atrial size assessment on ECG in patients with Mitral Stenosis using P Wave parameters and taking Transthoracic Echo as Gold Standard

MATERIAL AND METHODS: This cross-sectional study was conducted over six months at People’s University of Medical and Health Sciences for Women, Nawabshah. A total of 132 patients with suspected or diagnosed rheumatic mitral stenosis, aged 18–65 years, were enrolled based on predefined inclusion and exclusion criteria. A 12-lead ECG, focusing on lead II, were used to measure P-wave duration, amplitude, and area calculated as ½ × P-wave duration × amplitude, averaged over three cardiac cycles. Transthoracic echocardiography (TTE) was performed in the left lateral decubitus position, and LA diameter was measured at end-systole from the apical four-chamber view. LA enlargement was defined as a diameter ?40 mm.

RESULTS: The study included 132 patients (56.1% males, 43.9% females) with a mean age of 50 ± 3.06 years and average LV ejection fraction of 53.03 ± 6.61%. A strong correlation was found between P-wave area on ECG and LA diameter (r = 0.987, R² = 0.975), indicating that P-wave area explains 97.5% of LA size variability. A P-wave area ?4 ms·mV showed 85.42% sensitivity and 66.67% specificity, while amplitude >2.5 mm had 71.9% sensitivity and 63.9% specificity. P-wave duration >120 ms offered 76% sensitivity and 69.4% specificity. These results suggest ECG is a useful adjunct but not a standalone tool for detecting LA enlargement.

CONCLUSION

ECG-derived P-wave indices, particularly P-wave area, show a strong correlation with LA diameter and offer moderate diagnostic accuracy for detecting LA enlargement. While not definitive alone, ECG can serve as a valuable non-invasive screening tool in clinical practice.