Pathophysiology of impaired right and left ventricular function in chronicembolic pulmonary hypertension - Changes after pulmonary thromboendarterectomy

Study objectives: This study sought to evaluate the pathophysiology of left and right heart failure in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who were hospitalized to undergo pulmonary thromboenda rterectomy (PTE). Design: Thirty-nine patients (16 women and 23 men; mean /- SD age, 55 +/- 12 years) with severe CTEPH were examined before and 13 /- 8 days after PTE by way of transthoracic echocardiography and right hear t catheterization. Measurements ana results: Examination results confirmed in all cases that b efore surgery the right ventricles were enlarged and systolic function was impaired. Moderate to severe tricuspid valve regurgitation was observed. Le ft ventricular eccentricity indexes reflected a leftward displacement of th e interventricular septum. End-diastolic left ventricular size and systolic function had decreased, and the left ventricular filling pattern showed im paired diastolic function. After surgery, mean pulmonary artery pressure wa s significantly lower (48 +/- 10 mm Hg vs 25 +/- 7 mm Hg; p < 0.05). The ca lculated end-diastolic and end-systolic right ventricular areas had decreas ed: 30 +/- 7 cm(2) vs 21 +/- 5 cm(2) (p < 0.05) and 24 +/- 6 cm(2) vs 14 +/ - 4 cm(2) (p < 0.05), respectively. Right ventricular fractional area chang e had increased (20 +/- 7% vs 33 +/- 8%; p < 0.05). Most of the patients ex hibited a marked decrease in the severity of tricuspid regurgitation. Septa l motion, left ventricular systolic function, and diastolic filling pattern returned to normal values (early to late diastolic left ventricular inflow ratio, 0.70 +/- 0.33 vs 1.35 +/- 0.51; p < 0.05). The mean cardiac index a lso improved (2.7 +/- 0.6 L/min/m(2) vs 3.7 +/- 0.8 L/min/m(2)). Conclusions: In CTEPH, functions are impaired in the right as well as the l eft ventricles of the heart. Improved lung perfusion and the reduction of r ight ventricular pressure overload are direct results of PTE, which in turn bring a profound reduction of right ventricular size and a recovery of sys tolic function. Normalization of interventricular septal motion as well as improved venous return to the left atrium lead to a normalization of left v entricular diastolic and systolic function, and the cardiac index improves.