The value of echocardiographic left ventricular rotational body volume analysis in the assessment of patients with pulmonary hypertension.

Background: In patients with pulmonary hypertension (PH), subjective ventricular septal flattening is often used for qualitative grading when tricuspid regurgitation cannot be used to quantify pulmonary artery systolic pressure. The eccentricity index and septal curvature analysis in the left ventricular short-axis view may underestimate the afterload caused by post-systolic septal flattening in patients. In this study, the actual volume of the left ventricle of patients with PH was calculated from the two-dimensional apical four-chamber heart section using the mathematical method of volume calculus for rotating bodies. The changes in the morphology of the left ventricle were analyzed, and the severity of the disease and risk stratification of the patients were further evaluated. Additionally, its usefulness was examined compared to tricuspid regurgitation. Methods: In this study, 98 patients with PH diagnosed via right heart catheterization (RHC) and 35 normal controls were included. The end-systolic and end-diastolic standard volumes of the left ventricle were derived from the apical four-chamber view (A4C) of echocardiography (Echo) via mathematical rotation volume calculus and compared with the actual volume after compression. Furthermore, changes in the left ventricle area were assessed via a short-axis view. Results: Compared with those in the control group, the left ventricle morphological indicators in the PH group were significantly lower. An end-systolic left ventricle volume ratio of 0.925 was optimal for identifying the presence of PH. When this ratio decreased to 0.805 and 0.725, moderate and severe PH, respectively, were effectively distinguished. Furthermore, a short-axis end-diastolic left ventricle area ratio of 0.805 provided the best diagnostic performance for defining severe PH. Additionally, the end-diastolic volume ratio proved most effective in differentiating risk stratification for PH: patients were classified as low risk, with values between 0.925 and 0.795; moderate risk, with values from 0.794 to 0.715; and high risk, with values less than 0.715. Conclusions: A new sonographic measure of left ventricular volume change using mathematical rotational volume calculus, particularly the ratio of left ventricular end-systolic volume, could be a useful additional tool for assessing severity and risk stratification in patients with PH. When accurate estimation of pulmonary artery pressure via tricuspid regurgitation pressure gradients is challenging, the addition of this information improves the utility of Echo in the assessment of PH patients.