Preoperative plasma brain natriuretic peptide level is an independent predictor of postoperative atrial fibrillation following off-pump coronary artery bypass surgery.

PURPOSE: Atrial fibrillation (AF) is a frequent complication after coronary artery bypass surgery. Postoperative AF can lead to thromboembolic events, prolonged hospital stay, and increased costs. Recent reports have shown that an elevated plasma brain natriuretic peptide (BNP) level is associated with AF. The purpose of this prospective study was to test the hypothesis that preoperative BNP level is a predictor of postoperative AF following off-pump coronary artery bypass surgery (OPCAB). METHODS: One hundred and fifty patients without a history of AF undergoing elective isolated OPCAB were enrolled. Plasma BNP level was measured preoperatively. Heart rate and rhythm were continuously monitored during the first 72 h after surgery. RESULTS: Twenty-six patients (17.3%) exhibited postoperative AF. This proportion is similar to those reported in earlier studies. Univariate analysis demonstrated that age (odds ratio [OR], 1.060; 95% confidence interval [CI], 1.008 to 1.114; P = 0.023), previous myocardial infarction (MI; OR, 2.628; 95% CI, 1.031 to 6.697; P = 0.043), and BNP level (OR, 7.336; 95% CI, 2.401 to 22.409 / log BNP level; P < 0.001) were accurate predictors of postoperative AF. Stepwise multivariate regression analysis indicated age (OR, 1.059; 95% CI, 1.002 to 1.120; P = 0.043) and BNP level (OR, 6.272; 95% CI, 1.980 to 19.861/log BNP level; P = 0.002) as the only independent predictors of postoperative AF. CONCLUSION: Preoperative BNP level is an independent predictor of postoperative AF following OPCAB. Our findings permit us to stratify the risk of AF and to plan prophylactic strategies in high-risk patients.

The degree of newly emerging mitral regurgitation during off-pump coronary artery bypass is predicted by preoperative left ventricular function.

PURPOSE: During off-pump coronary artery bypass (OPCAB), the displacement of the heart causes mitral regurgitation. We hypothesized that patients with impaired left ventricle (LV) function would be more prone to develop mitral regurgitation, due to further LV end-diastolic pressure elevation and mitral annulus distortion. Therefore, in this study, we examined the relationship between LV function and the severity of mitral regurgitation. METHODS: We studied 41 patients undergoing elective OPCAB. LV function was evaluated by LV ejection fraction (LVEF), serum brain natriuretic peptide (BNP) levels, the Tei index (myocardial performance index) and mitral inflow propagation velocity (Vp). RESULTS: Among all of the anastomoses performed mitral regurgitation was most severe during anastomosis of the left circumflex artery (LCX) territory (P < 0.001). Twenty-five patients (61%) had no to mild mitral regurgitation during anastomosis of the LCX territory (M-MR group) and 16 patients (39%) had moderate to severe mitral regurgitation during anastomosis of the LCX territory (S-MR group). There were significant differences between these groups in preoperative serum BNP levels (median, 26 pg.ml(-1) interquartile range [IQR, 14 to 75 pg.ml(-1)] versus median, 173 pg.ml(-1) [IQR, 91 to 296 pg.ml(-1)]; P < 0.001), Tei index values (median, 0.35; [IQR, 0.27 to 0.41] versus median, 0.53 [IQR, 0.47 to 0.57]; P < 0.001), and Vp (median, 63 cm.s(-1); [IQR, 57 to 72 cm.s(-1)] versus median, 47 cm.s(-1); [IQR, 40 to 57 cm.c(-1)]; P = 0.008), while there was no significant difference in LVEF between the patients in the M-MR group and those in the S-MR group. CONCLUSION: Preoperative LV dysfunction is a predictor of severe mitral regurgitation during OPCAB. When poor LV function is suggested, it is necessary to be prepared for further hemodynamic deterioration caused by mitral regurgitation.

[Time course of thoracic epidural pressure and saphenous venous pressure changes with oxytocics after fetus delivery in parturients undergoing cesarean section].

BACKGROUND: We examined the effects of oxytotics administered after fetus delivery on epidural and venous pressures in 40 parturients undergoing cesarean section under spinal anesthesia. METHODS: The subjects received 0.5% isobaric bupivacaine for spinal anesthesia. An epidural catheter placed at T11-12 and a venous catheter placed at left saphenous vein, were connected to pressure transducers to monitor each pressure. The subjects received intravenous methylergometrine 0.2 mg (methylergometrine group: n=20) or oxytocin 10 IU (oxytocin group: n=20) immediately after fetus delivery. Intramyometrial PGF2alpha was additionally administered from 5 minutes after fetus delivery in case of low uterine tone. Statistic analysis was performed with ANOVA. RESULTS: Epidural pressure in the methylergometrine group increased at placental delivery and the increase continued until 15 minutes after delivery (P<0.05). Epidural pressure in the oxytocin group increased at placental delivery and began to decrease at 5 minutes after delivery (P<0.05). Saphenous venous pressure began to increase at 10 minutes after delivery in the methylergometrine group (P<0.05). CONCLUSIONS: The increase in epidural pressure within 5 minutes after fetus delivery would be caused by uterine contraction in both groups. The vasoconstrictive effect in the methylergometrine group is likely to cause the epidural pressure increase after delivery.