Preliminary Study On Cardiopulmonary Bypass Early Hemodynamic Mitral Valve Replacement

Objective:To evaluate the differences of the cardiac index (CI) between transmitral and transascending arota estimated by transesophageal echocardiography (TEE) undergoing mitral valve replacement (MVR).Methods:Sixteen patients with age<70yr, male or female, preoperatively ASA Ⅱ-Ⅲ, NYHAⅡ-Ⅲ and EF≥45%, scheduled for mitral valve replacement are studied. Complete intravenous general anesthesia was used in anesthesia induction and during intraoperative anesthesia.After anesthesia induction we put the TEE probe into the esophagus. Measurements were made after cardiopulmonary bypass (T1), after cardiopulmonary bypass thirty minutes (T2) and after cardiopulmonary bypass sixty minutes (T3). Statistical analysis was made with Bland and Altman method.Results:Ninety-six measurements were compared. The CIMV values ranged from1.2to5.5L·min-1·m-2(mean2.6±0.9).The Values of CIAA ranged from2.7to8.8L·min-1·m-2(mean4.8±1.7).Bias was-2.3L-min-1·m-2and limits of agreement-5.6to1.0L·min-1·m-2.Conclusion:During mitral valve replacement, clinically good correlations and feasibility were observed between values of CI measured through mitral valve and ascending arota used transesophageal echocardiography. However, compared with clinical standard, the CI values were more practical. Objective:To observe the early effects of dopamine on patients undergoing mitral valve replacement (MVR) after cardiac pulmonary bypass (CPB) on left ventricular contraction, hemodynamics and urine volume, so as to revaluate the clinical effects of dopamine on patients undergoing open heart operation.Methods:Eighteen patients with American Society of age<70yr, male or female, preoperatively Anesthesiologists status (ASA) Ⅱ～Ⅲ, NYHAⅡ～Ⅲ,EF≥45%and without using cardiotonic agents, scheduled for pure mitral valve replacement were studied. Complete intravenous general anesthesia was used in anesthesia induction and during intraoperative anesthesia. The patients were divided into two groups:D group (n=8) and F group (n=10). D group:after cardiac pulmonary bypass with continuous infusion dopamine intravenously; F group:without receiving dopamine intravenously. With controlling the coincidence of ventricular rate by pacemaker, cardiac index(CI), left ventricular ejection fraction(LVEF), central venous pressure(CVP), mean arterial pressure(MAP), systemic vascular resistance index(SVRI), the value of lactic acid, urine volume and phenylephrine dosage were compared between two groups after cardiac pulmonary bypass.Results:Within group D and F, the values of the examinations had no statistical significance(p>0.05). There was no differences in the levels of CI, LVEF, CVP, MAP, SVRI, lactic acid value, urine volume and phenylephrine dosage between two groups at the same points(p>0.05). However, the urine volume of groups D and F had statistical significance (p<0.05). Conclusion:In this study, the result suggests that it isn’t necessary for the normal heart function of the patients undergoing mitral valve replacement after cardiac pulmonary bypass to receive prophylactic dopamine, but obviously increasing urine output. Objective:To evaluate the whole and local systolic and diastolic function before and after cardiopulmonary bypass (CBP) by tissue Doppler echocardiography (TDI) during mitral valve replacement (MVR).Methods:Twenty patients with male or female (8men,12women, age<70yr, male or female, preoperatively ASA Ⅱ～Ⅲ, NYHA Ⅱ～Ⅲand EF≥45%,), scheduled for mitral valve replacement with cardiopulmonary bypass are studied. The cardiac systolic and diastolic parameters were determined at three periods by practical TEE and TDI following MVR:To after anesthesia induction and before sternotomy, T3030minutes after cessation of bypass, T9090minutes after cessation of bypass. We determined the parameters as follows:1) the early diastolic transmitral velocity (E);2) the early diastolic tissue velocity (Ea) and calculated the ratio(E/Ea);3)the average velocity of anterior and posterior wall of left ventricle in isovolumetric contraction (Sm1) and ejection period (Sm2); and calculation the ratio (Em/Am); the average velocity of anterior and posterior wall of left ventricle in early (Em) and later diastolic period (Am) and calculation the ratio (Em/Am);4) the left ventricular ejection fraction (LVEF). During three periods, we determined heart rate (HR), mean arterial blood pressure (MAP), cardiac index (CI) and central venous pressure (CVP).Results:The basic hemodynamic parameters(HR、MAP、CVP、CI、LVEF) had no statistical significance(P>0.05). Compared with Sm2, Sml increased at To (9.2±3.0cm/s vs7.3±1.8cm/s, P<0.01) and at T90(7.4±1.9cm/s vs6.7±1.9cm/s, P<.05). Among two groups, there was no statistical significance at T30(P>0.05). The other examinations had no statistical significance (P>0.05).Conclusion:In this study, the whole and local systolic and diastolic function of the early left ventricular had not been obviously damaged after CBP by TDI. But we must still pay attention on the diastolic function after mitral valve replacement.