Role of electrocardiographic changes in discriminating acute or chronic right ventricular pressure overload

Objective: Pulmonary embolism (PE) and severe pulmonary stenosis (PS) are two distinct conditions accompanied by increased pressure load of the right ventricle (RV). Despite major advances in our understanding of the mechanisms of RV adaptation to the increased pressure, substantial gaps in our knowledge remain unsettled. One much less known aspect of pressure overload of RV is its impact on electrocardiographic (ECG) changes. In this study, we aimed to study whether acute and chronic RV overload are accompanied by different ECG patterns. Methods: Thirty-eight patients with PE underwent ECG monitoring and were compared with 20 matched patients with PS. ECG abnormalities suggestive of RV overload were recorded and analyzed in both groups. Results: Among the ECG changes studied, premature atrial contraction (p = 0.008), right axis deviation (p < 0.001), indeterminate axis (p = 0.001), incomplete right bundle branch block (p = 0.02), late R in aVR (p = 0.001), qR in V1 (p = 0.02), and P pulmonale (p = 0.03) were significantly more common in patients with PS than in those with acute PE. Conclusion: Our data indicate that the ECG changes that attributed to the acute RV pressure loading states may be more prevalent in chronic RV overload as compared with acute RV overload.