Study on the late effect of pneumonectomy on right heart pressures using Doppler echocardiography.

OBJECTIVE Changes in the pulmonary artery systolic pressure (PASP) and the dimensions of the right ventricle (RV) of the heart, six months after pneumonectomy, were evaluated in order to detect the influence of pneumonectomy on right heart function. METHODS 35 patients undergoing pneumonectomy (Group A) and 17 patients undergoing lobectomy or bilobectomy (Group B) were evaluated prospectively with spirometry, arterial blood gases determination and Doppler echocardiography at rest, preoperatively and six months postoperatively. Patients of both groups had normal preoperative PASP, RV dimensions and left ventricular ejection fraction. PASP was calculated using the equation: PASP=4x(maximal velocity of the tricuspid regurgitant jet)2+10 mmHg. FEV1, FVC, partial pressures of oxygen (pO2) and carbon dioxide in the arterial blood were considered as the main determinants of postoperative lung function. RESULTS PASP increased significantly six months postoperatively in both groups (P<0.05). Mean PASP in Group A (40.51+/-12.52 mmHg) was significantly higher (P=0.012) than in Group B (32.88+/-5.25 mmHg). Mean PASP after right pneumonectomy (48.33+/-10.61 mmHg) was significantly higher (P=0.002) than after left pneumonectomy (35.26+/-10.83 mmHg). The incidence of RV dilatation was higher in Group A (60%) than in Group B (23.52%). RV dilatation was related with elevated PASP values in both groups (P<0.001 and P=0.034, respectively). Increased age (P<0.001), significant percent FVC reduction from preoperative values (P=0.012) and low pO2 values (P=0.001) were detected as strong predisposing factors for postpneumonectomy PASP elevation. CONCLUSIONS Pneumonectomy is related with postoperative elevation of PASP and RV dilatation, especially right pneumonectomy. Significant percent FVC reduction, increased age and low pO2 values are the main responsible factors for elevation of the 6-month postoperative PASP values.