Abstract
After lung resection, it is recognized that reduction of the pulmonay vascular bed increases right ventricular afterload and influence right ventricular function. Therefore, we investigated how right ventricular function changes after lobectomy and pneumonectomy, measuring hemodynamics including right ventricular ejection fraction (RVEF) and right ventricular end-diastolic volume index (RVEDVI). 35 patients who had received lobectomy and 16 patients who had received pneumonectomy for lung cancer were examined.
After lobectomy, right ventriclar afterload increased slightly, as stroke volume decreased but cardiac index increased. The decrease of RVEDVI might reduce stroke volume. However, the increase of heart rate increased the cardiac index as compared to the preoperative value. Right ventricular function was tolerant of the stress after lobectomy.
After pneumonectomy, right ventriclar afterload increased significantly. Not only stroke volume decreased but cardiac index was also not stable. The decrease of RVEF might reduce stroke volume. Heart rate increased but cardiac index was not stable. This suggests that the increase of heart rate can not compensate for the decrease of stroke volume and the tendency of right ventricular failure after pneumonectomy.
The change of RVEDVI was not correlated with that of mean right atrial pressure. Therefore, investigation of RVEDVI was useful for evaluating the right ventricular preload.
Investigating hemodynamics including RVEF and RVEDVI is a reliable means to evaluate the right ventricular load and compensation influenced by the right ventricular afterload.
