Changes of Brain Natriuretic Peptide Levels according to Right Ventricular HemodynaMics after a Pulmonary Resection / 대한흉부외과학회지

BACKGROUND: The correlation between levels of brain natriuretic peptide (BNP) and the effect of pulmonary resection on the right ventricle of the heart is not yet widely known. This study aims to assess the relationship between the change in hemodynamic values of the right ventricle and increased BNP levels as a compensatory mechanism for right heart failure following pulmonary resection and to evaluate the role of the BNP level as an index of right heart failure after pulmonary resection. MATERIAL AND METHOD: In 12 non small cell lung cancer patients that had received a lobectomy or pnemonectomy, the level of NT-proBNP was measured using the immunochemical method (Elecsys 1010(R), Roche, Germany) which was compared with hemodynamic variables determined through the use of a Swan-Ganz catheter prior to and following the surgery. Echocardiography was performed prior to and following the surgery, to measure changes in right ventricular and left ventricular pressures. For statistical analysis, the Wilcoxon rank sum test and linear regression analysis were conducted using SPSSWIN (version 11.5). RESULT: The level of postoperative NT-proBNP (pg/mL) significantly increased for 6 hours, then for 1 day, 2 days, 3 days and 7 days after the surgery (p=0.003, 0.002, 0.002, 0.006, 0.004). Of the hemodynamic variables measured using the Swan-Ganz catheter, the mean pulmonary artery pressure after the surgery when compared with the pressure prior to surgery significantly increased at 0 hours, 6 hours, then 1 day, 2 days, and 3 days after the surgery (p=0.002, 0.002, 0.006, 0.007, 0.008). The right ventricular pressure significantly increased at 0 hours, 6 hours, then 1 day, and 3 days after the surgery (p=0.006, 0.009, 0.044, 0.032). The pulmonary vascular resistance index [pulmonary vascular resistance index=(mean pulmonary artery pressure-mean pulmonary capillary wedge pressure)/cardiac output index] significantly increased at 6 hours, then 2 days after the surgery (p=0.008, 0.028). When a regression analysis was conducted for changes in the mean pulmonary artery pressure and NT-proBNP levels after the surgery, significance was evident after 6 hours (r=0.602, p=0.038) and there was no significance thereafter. Echocardiography displayed no significant changes after the surgery. CONCLUSION: There was a significant correlation between changes in the mean pulmonary artery pressure and the NT-proBNP level 6 hours after a pulmonary resection. Therefore, it can be concluded that changes in NT-proBNP level after a pulmonary resection can serve as an index that reflects early hemodynamic changes in the right ventricle after a pulmonary resection.

Cardiac Function Changes According to the Type of Operation for Mitral Regurgitation / 대한흉부외과학회지

BACKGROUND: Before the development of an ideal artificial valve, repairing of native valves was considered the best choice and clinicians have been reported that valvuloplasty was much better than valve replacement, when possible with the respect to clinical outcomes. This study was conducted under the hypothesis that in some cases, the surgical and clinical outcomes could be better in patients with valve replacement and it may be influenced by left ventricular function. MATERIAL AND METHOD: This study included 40 patients who received pure mitral valve regurgitation. We divided the patients into three groups(Group I: classical valve replacement in 12 patients, Group II: preserving posterior leaflet in 18 patients, Group III: valvuloplasty in 10 patients) and compared the patient`s clinical findings, echocardiographical indexes obtained at admission and 4 weeks after operation. RESULT: After operation, Group II and III showed the better clinical condition changes than Group I but there was no statistical significance. According to NYHA classification, favorable results were achieved but there are no statistical significances in these three patient groups. The left ventricular function was worsened in Group I and in the Groups II and III, the left ventricular function showed no changes postoperatively. In Groups II and III, there were improvements in the postoperative clinical findings but the left ventricular ejection fraction revealed no statistical differences in these two groups. CONCLUSION: Due to different left ventricular functions, repair is considered a better method for the mitral regurgitation. If there the deformity is impossible to repair, preserving a portion of the leaflet is the preferred surgical method.

Influence of Prosthesis Size on Change in Left Ventricular Hypertrophy Following Aortic Valve Replacement / 대한흉부외과학회지

BACKGROUND: Aortic valve stenosis induces left ventricular hypertrophy as an adaptive response to the chronic overload caused by the valve disease. Despite the fact that aortic valve replacement may lead to regression of the left ventricular hypertrophy, there is a controversy on the change of the left ventricular muscle after use of small prostheses. MATERIAL AND METHOD: We reviewed 20 patients who had undergone aortic valve replacement for aortic stenosis. There were 13 males and 7 females with a mean age of 61+/-13.8 years. A retrospective analysis of Doppler echocardiography was undertaken in preoperatively, early postoperatively(mean 10.4days), and late postoperatively(mean 29.9 months). They were divided into two groups according to the size of prosthesis used(group 1; 21 mm or smaller, group 2; 23 mm or larger). RESULT: Significant improvement of NYHA Functional class was detected in all groups. Ejection fraction was not significantly different in the group 1 between preoperative and postoperative period, however it increased significantly in the group 2 over time. But preoperative ejection fraction of the group 2 was significantly lower than that in the group 1(p=0.044). Left ventricular muscle mass index(g/m2) was not reduced significantly in the group 1 at the early postoperative period, but it was reduced significantly at the late postoperative period. In the group 2 it was reduced significantly over time. CONCLUSION: Both groups showed clinical improvement. However, the number of patients in whom 19 mm size prosthesis was used was only two. Thus, we suggest that more attention to age, BSA, and exercise should be paid in patients who will undergo aortic valve.

Early Results of Coronary Bypass Surgery in Patients with Severe Left Ventricular Dysfunction / 대한흉부외과학회지

From March, 1992 to March, 1996, a total of 279 patients underwent coronary bypass surgery at the Sejong General Hospital, Puchon. We selected 22 patients with severe left ventricular(LV) dysfunction from them. The criteria were the presence of global or segmental abnormalities of left ventricular contraction and LV ejection fraction(EF) less than 35% based on biplane LV angiography by planimetry method. The mean age of 17 male and 5 female patients was 60+/-5.6years(range:47~73 years). All had the anginas, which were Canadian class II in 6, class III in 12 and class IV in 4. All patients except one had the history of previous myocardial infarction more than once. Seven of them had the symptoms and signs of congestive heart failure, such as dyspnea on excertion and increased pulmonary vascular markings. Their mean LVEF was 29.4+/-4 5%(range : 18~35%) and mean LV end-diastolic pressure was 18.7 +/-8. 2mmHg(range:10~42mmHg). 21 patients had 3 vessel-disease and 1 had 2 vessel-disease. Complete revascularization was tried with the use of 16 internal mammary arteries and 60 sapheuous veins and 3 radial arteries grafts. The mean number of distal anastomosis was 3.5+/-1.1. Concomitantly, one mitral valvuloplasty and annuloplasty was performed in the patient with moderate mitral regurtigation. The hospital mortality was 4.5%. During the follow-up, there were 3 late deaths. Of 18 survivors, 2 patients were lost in follow-up 24 and 27 month respectively after operation and the remaining 16 patients have bcen followed up with an average of 30.4 +/-13.4 months.15 patients had improvement with respect to angina but 8 patients still have the continuing or progressing heart failure. The 1-year, 2-year and 3-year actuarial survival rate was 85.2, 69.1, 46.1%, respectively. This study indicates that coronary artery bypass sur ery can be performed in the patients with severe LV dysfunction at acceptable risk but does not greatly contribute to the improvement of congestive heart failure.