Which Type of Right Ventricular Pressure Overload is Worse? An Echocardiographic Comparison between Pulmonary Stenosis and Pulmonary Arterial Hypertension

Background: Some studies have evaluated the right ventricular (RV) function in volume-overload and pressure-overload conditions and have always categorized pulmonary arterial hypertension (PAH) in the latter group. However, PAH and pulmonary stenosis (PS) are two frequent diseases, both resulting in the RV pressure overload. Objectives: The aim of this study was to evaluate the RV response to two causes of the RV pressure overload: severe PAH and PS. Patients and Methods: Eighteen patients with PAH at a mean age of 43 ± 12 years (66.6% female) and 16 patients with PS at a mean age of 33 ± 17 years (56.35% female) were enrolled. Standard echocardiography, tissue Doppler, and longitudinal strain imaging at the base, mid, and apical levels of the RV free wall were done. Results: Significant tricuspid regurgitation was more prevalent in the PAH group than in the PS group (61% vs. 18.5%; P < 0.001). The abnormalities in the RV myocardial performance index, RV areas, and RV fractional area change were significantly more robust in the PAH group (all Ps < 0.05) despite the higher net RV systolic pressure in the PS group as compared to the PAH group (121 ± 39 vs. 88 ± 26 mmHg; P < 0.001). Conclusions: It seems that severe PAH aggravates the RV function more severely.