Effects of lidoflazine on left ventricular function in patients

A

Propofol preservation of myocardial function in patients undergoing coronary surgery using cardiopulmonary bypass is dose dependent [6] (multiple letters)

link_to_subscribed_fulltex

Inotropic effects of sodium nitroprusside: A clinical study on coronary surgery patients

OBJECTIVE: Sodium nitroprusside (SNP) induces release of nitric oxide and is widely used as a vasoactive drug. Recent research analyzed effects of SNP on cardiac muscle and described variable inotropic effects. The present study evaluated effects of SNP on left ventricular (LV) function in patients undergoing coronary artery surgery. METHODS: The study was performed in 100 patients with a preoperative ejection fraction > 40%. LV pressures were measured with a fluid-filled catheter in the LV cavity. Hearts were placed in AV sequential mode at a rate of 90 beats/min. Measurements were obtained at end-expiration and consisted of a control tracing and a tracing obtained after a 5 min infusion of SNP 0.5 microgram.kg-1.min-1. These measurements were obtained before and after cardiopulmonary bypass (CPB). An average of 5 consecutive beats was obtained for analysis. Ventricular function was assessed with LV pressure and dP/dt. Data were analyzed using two factor analysis of variance for repeated measurements. RESULTS: 1. Baseline patient data (n = 80). Before CPB, a variable inotropic response to SNP was observed. The direction of the inotropic response was related to preoperative beta-blocking medication. LVP and dP/dtmax increased with SNP in patients without preoperative beta-blocking medication. In patients on preoperative beta-blocking medication, SNP did not alter LVP and dP/dtmax. After CPB, a positive inotropic response was not observed in any of the patients. 2. Postoperative patient data under dobutamine (n = 20). Data of these separate observations were similar to baseline data before CPB. After CPB and under dobutamine administration (5 micrograms.kg-1.min-1) all 20 patients developed a positive inotropic response to SNP. CONCLUSIONS: In coronary surgery patients, SNP induced variable inotropic effect. The direction of the inotropic response appeared to be modulated by the beta-adrenergic driv

Contraction-relaxation coupling and impaired left ventricular performance in coronary surgery patients

BACKGROUND: Dependence of left ventricular (LV) relaxation on cardiac systolic load is a function of myocardial contractility. The authors hypothesized that, if a tight coupling would exist between LV contraction and relaxation, the changes in relaxation rate with an increase in cardiac systolic load would be related to the changes in LV contraction. METHODS: Coronary surgery patients (n = 120) with preoperative ejection fraction >40% were included. High-fidelity LV pressure tracings (n = 120) and transgastric transesophageal echocardiographic data (n = 40) were obtained. Hearts were paced at a fixed rate of 90 beats/min. Effects on contraction were evaluated by analysis of changes in dP/dt(max) and stroke area. Effects on relaxation were assessed by analysis of R (slope of the relation between tau and end-systolic pressure). Correlations were calculated with linear regression analysis using Pearson's coefficient r. RESULTS: Baseline LV end-diastolic pressure was 10+/-3 mm Hg (mean +/- SD). During leg raising, systolic LV pressure increased from 93+/-9 to 107+/-11 mm Hg. The change in dP/dt(max) was variable and ranged from -181 to +254 mm Hg/s. A similar variability was observed with the changes in stroke area, which ranged from -2.0 to +5.5 cm2. Changes in dP/dt(max) and in stroke area were closely related to individual R values (r = 0.87, P <0.001; and r = 0.81, P <0.001, respectively) and to corresponding changes in LV end-diastolic pressure (r = 0.81, P <0.001; and r = 0.74, P <0.001, respectively). CONCLUSIONS: A tight coupling was observed between contraction and relaxation. Leg raising identified patients who developed a load-dependent impairment of LV performance and increased load dependence of LV relaxatio