Association Between Electrocardiographic Left Atrial Enlargement and Echocardiographic Left Atrial Indices Among Hypertensive Subjects in a Tertiary Hospital in South South Nigeria.

Introduction: Left atrial (LA) enlargement poses a clinically significant risk of adverse cardiovascular outcomes for patients. To maximize the utility of LA size in diagnosis, its accurate measurement using electrocardiogram (ECG) and echocardiogram (ECHO) to assess LA linear diameter and LA volumes is expedient. The LA volumes correlate better than LA linear diameter with diastolic function variables. It is therefore expedient to use LA volumes routinely in assessing LA size as they may detect early and subtle changes in LA size and function.

Methods: A descriptive cross-sectional study was conducted on 200 adult hypertensive patients attending the outpatient cardiology clinic at Delta State University Teaching Hospital, Oghara, Nigeria, irrespective of blood pressure control and duration of hypertension whether on antihypertensive medications or not. The SPSS version 22 (IBM Corp., Armonk, NY, USA) was used for data management and analysis.

Result: There was a significant association between electrocardiographic left atrial (ECG-LA) enlargement and echocardiographic left atrial (ECHO-LA) size (LA linear diameter and LA maximum volume) in the study. Logistic regression analysis showed a significant odds ratio for all associations. With LA linear diameter as standard for assessing LA enlargement, the ECG had a sensitivity of 19%, specificity of 92.4%, a positive predictive value of 51%, and a negative predictive value of 73% in detecting LA enlargement. Using ECHO-LA maximum volume as a standard for assessing LA enlargement, the ECG had a sensitivity of 57.3%, a specificity of 67.7%, a positive predictive value of 42.9%, and a negative predictive value of 79% in detecting LA enlargement. The LA maximum volume showed relatively higher sensitivity and negative predictive values while LA linear diameter showed relatively higher specificity and positive predictive values.

Conclusion: A good association exists between ECG-LA enlargement and ECHO-LA enlargement. However, in ruling out LA enlargement on ECG, it is better to use LA maximum volume as a standard rather than the LA linear diameter.