Construction of right ventricular pulmonary artery coupling model in patients with pulmonary hypertension / 中国介入心脏病学杂志

ABSTRACT

Objective To study the mechanism of right ventricular pulmonary artery coupling by fitting the pressure volume loop of pulmonary arterial hypertension patients and calculating the related parameters.Methods During January of 2015 to December of 2015,34 patients with pulmonary hypertension and 5 patients with patent oval foramen(PFO)were admitted in Wuhan Asian Heart Hospital,. Inclusion criteria for the pulmonary hypertension group were in accordance with the newest European guidelines for pulmonary hypertension . All of the patients were conducted invasive pressure catheter intervention and MRI. All the pressure data were digitized by GetData software and the CMR tools3D was used to derive right ventricular volume data, fitting the pressure volume loop and calculate the Pmax, Ees, Ea and other related parameters. 5 patients with PFO and 34 patients with pulmonary hypertension were divided into three groupswhich includedthe control group (i.e. the patients with PFO), patients with pulmonary artery mean pressure less than 50 mmHg as group A and pulmonary artery mean pressure greater than or equal to 50 mmHg as group B. The pressure volume loop of the three groups were compared and the related parameters were calculated.Results The right ventricular Pmax were(53.05±12.87) mmHg, (134.73±26.38) mmHg, (207.88±65.67) mmHg, in the control group, group A and B respectively. There were significant differences when compared among the 3 groups. There was no statistical difference in Ees between the control group and group A(P>0.05). The Ees of group B was significantly higher than the control group[(1.53±0.97)vs.(0.60±0.28),P<0.05]. The Ea of group B was higher than the control[(1.34±0.74) vs.(0.39±0.15),P<0.05]. The overall ratio of Ees/Ea was lower in group B as compared to the control group [(1.12±0.47)vs.(1.62±0.51),P<0.05].Conclusions In the early stage of pulmonary hypertension, right ventricular contractility preserves and can overcome the slightly elevated afterload .The right ventricle and pulmonary artery coupled with good work. With the increasing mean pulmonary artery,the afterload of right ventricular increases and right ventricular contractility needs further increase to fight against the elevated afterload. The elevation of contractility cannot overcome the change of afterload, resulting in the off paired of mechanical efflciency, causing the right ventricle- pulmonary artery coupling decreases.