Isoflurane's Effect on Intraoperative Systolic Left Ventricular Performance in Cardiac Valve Surgery Patients.

BACKGROUND: Isoflurane, a common anesthetic for cardiac surgery, reduced myocardial contractility in many experimental studies, few studies have determined isoflurane's direct impact on the left ventricular (LV) contractile function during cardiac surgery. We determined whether isoflurane dose-dependently reduces the peak systolic velocity of the lateral mitral annulus in tissue Doppler imaging (S') in patients undergoing cardiac surgery. METHODS: During isoflurane-supplemented remifentanil-based anesthesia for patients undergoing cardiac surgery with preoperative LV ejection fraction greater than 50% (n = 20), we analyzed the changes of S' at each isoflurane dose increment (1.0, 1.5, and 2.0 minimum alveolar concentration [MAC]: T1, T2, and T3, respectively) with a fixed remifentanil dosage (1.0 µg/min/kg) by using transesophageal echocardiography. RESULTS: Mean S' values (95% confidence interval [CI]) at T1, T2, and T3 were 10.5 (8.8-12.2), 9.5 (8.3-10.8), and 8.4 (7.3-9.5) cm/s, respectively (P < 0.001 in multivariate analysis of variance test). Their mean differences at T1 vs. T2, T2 vs. T3, and T1 vs. T3 were -1.0 (-1.6, -0.3), -1.1 (-1.7, -0.6), and -2.1 (-3.1, -1.1) cm/s, respectively. Phenylephrine infusion rates were significantly increased (0.26, 0.22, and 0.47 µg/kg/min at T1, T2, and T3, respectively, P < 0.001). CONCLUSION: Isoflurane increments (1.0-2.0 MAC) dose-dependently reduced LV systolic long-axis performance during cardiac surgeries with a preserved preoperative systolic function.

Effects of sevoflurane increments on left ventricular systolic long-axis performance during sevoflurane-remifentanil anesthesia for cardiovascular surgery.

BACKGROUND: The direct impact of sevoflurane on intraoperative left ventricular (LV) systolic performance during cardiac surgery has not been fully elucidated. Peak systolic tissue Doppler velocities of the lateral mitral annulus (S') have been used to evaluate LV systolic long-axis performance. We hypothesized that incremental sevoflurane concentration (1.0-3.0 inspired-vol%) would dose-dependently reduce S' in patients undergoing cardiac surgery due to mitral or aortic insufficiency. METHODS: In 20 patients undergoing cardiac surgery in sevoflurane-remifentanil anesthesia, we analyzed intraoperative S' values which were determined after 10 min exposure to sevoflurane at 1.0, 2.0, and 3.0 inspired-vol% (T1, T2, and T3, respectively) with a fixed remifentanil dose (1.0 µg/kg/min) using transesophageal echocardiography. RESULTS: Linear mixed-effect modeling demonstrated dose-dependent declines in S' according to the end-tidal sevoflurane concentration increments (C(ET)-sevoflurane, p < 0.001): the mean value of S' reduction for each 1.0 vol%-increment of C(ET)-sevoflurane was 1.7 cm/s (95 % confidence interval 1.4-2.1 cm/s). Medians of S' at T1, T2, and T3 (9.6, 8.9, and 7.5 cm/s, respectively) also exhibited significant declines (by 6.6, 15.6, and 21.2 % for T1 vs. T2, T2 vs. T3, and T1 vs. T3, p < 0.001, =0.002, and <0.001 in Friedman pairwise comparisons, respectively). CONCLUSIONS: Administering sevoflurane as a part of a sevoflurane-remifentanil anesthesia regimen appears to dose-dependently reduce S', indicating LV systolic performance, in patients undergoing cardiac surgery. Further studies may be required to evaluate the clinical implications of these findings.

Usefulness of intraoperative real-time three-dimensional transesophageal echocardiography in preprocedural evaluation of cortriatriatum -a case report-.

Cortriatriatum is a rare congenital cardiac disorder with fibromuscular band (diaphragm) dividing the left atrium (LA) into the proximal and distal parts. Surgical correction of cortriatriatum requires full preoperative evaluation of the structural anomalies including the LA diaphragm and their pathophysiology. In the present case, a 44 year-old lady diagnosed as cortriatriatum underwent surgical correction. Intraoperative three-dimensional transesophageal echocardiography provided detailed information regarding the shape and extent of the LA diaphragm, which had been partially evaluated by preoperative two-dimensional transthoracic and transesophageal echocardiography, and facilitated the intraoperative patient management and surgical decision making.