Electrocardiogram and left atrial abnormality: Design of an observational study to clarify diagnostic criteria

Background The criteria applied for diagnosis of left atrial (LA) abnormality using electrocardiogram (ECG) have high specificity but low sensitivity. In fact, some authors have suggested classifying P-wave anomalies associated with LA abnormality and interatrial block as "atrial abnormalities." The most widely known ECG criteria for LA abnormality include P-wave duration, morphology and voltage of P wave in inferior leads, presence of P-wave terminal force in V-1 (PtfV(1)), and P-wave axis and area. PtfV(1) has also been reported to vary according to misplacement of the V-1 and V-2 electrodes. Methods The objective of this observational cohort study is to determine the degree of correlation between ECG criteria for LA abnormality and left atrium volume and functionality, as determined by speckle tracking echocardiography. The study also aims to investigate the correlation between these echocardiographic parameters and PtfV(1) value by placing the V-1 and V-2 electrodes in the second, third, and fourth intercostal spaces. Results and Conclusions Our results could help to clarify whether the decrease in left atrial deformity, which is currently considered a surrogate target of fibrosis, correlates better with ECG criteria for LA abnormality than atrial volumes.