The Value of P-Pulmonale as an Electrocardiographic Criterion for Detection of Right Atrial Dilatation

Background and objectives: There are many electrocardiographic (ECG) criteria for detection of right atrial dilatation (maximum diameter of more than 5.3 mm), the most common one is P- pulmonale which is manifested by a tall P- wave in the inferior leads mainly lead II (P- wave equal or more than 2.5 mm), although this criteria is subjected to criticism regarding its sensitivity, specificity and predictive values, but it is still regarded as a main criteria. This study was designed to estimate the sensitivity, specificity, predictive values and accuracy of P- pulmonale in the detection of right atrial dilatation. Methods: Two hundred patients with different pathologies that can lead to right atrial dilatation had been included in the study from 2013-7-1 to 2015-9-1. ECG and two dimensional chocardiography had been performed for all patients, P- wave in lead II of 2.5 mm or more had been regarded as P- pulmonale, right atrial maximum dimension in apical four chamber view transthoracic two dimensional echocardiography of more than 5.3 mm had been regarded as dilated right atrium. The patients accordingly were divided into four groups (true positive, true negative, false positive and false negative). Results: The study included patients of different ages, male to female ratio was 3:2, and the patients had different pathologies that could lead to dilated right atrium. Sensitivity of P-pulmonale was %49, specificity %79, positive predictive value of %51, negative predictive value of 77 % and accuracy] of %70.5. Conclusions: P-pulmonale is a reliable criterion for the detection of right atrial dilatation although it has variable sensitivity. It is more specific than being sensitive. The negative predictive value of P-pulmonale is higher than its positive predictive value.