The combined effect of systemic hypertension and obesity on biventricular diastolic function

Left ventricular (LV) cardiomyopathy in hypertensive obese patients is a consequence of increased LV afterload due to systemic hypertension and increased LV pre-load subsequent to the augmentation of total blood volume in obese. However, little is known about right ventricular (RV) functional status and biventricular interaction in patients with systemic hypertension and concurrent obesity. The aim of our study was the echocardiographic assessment of left and right ventricular function and diastolic performance in hypertensive obese patients. The study group consisted of 31 subjects with BMI > 26 kg/m2 and mild to moderate systemic hypertension, patients with systemic hypertension and normal BMI served as a control group. M-mode echocardiographic measurements of left and right ventricles were performed. By pulsed Doppler echocardiography LV and RV recordings of diastolic filling and systolic flows in pulmonary artery were obtained. Hypertensive obese patients demonstrated significantly thicker posterior wall and enlarged left atrium, while no differences in RV structure were found between both groups. In obese subjects we showed significantly lower LV early to late filling wave velocity ratio and LV early to late filling wave velocity-time-integral ratio (p < 0.01). Only RV early to late filling wave velocity-time-integral ratio differentiated obese and lean subjects (p < 0.05). In obese subjects we demonstrated significantly increased mean pulmonary artery pressure. The results of our study indicate that RV is protected from the direct influence of hemodynamic changes observed in overweight/obesity better than the left ventricle and RV abnormalities in patients with systemic hypertension and obesity depend mainly on increased RV afterload, secondary to LV dysfunction.