PubMed Health⌕ Search

Biomedical subjects

I E Rodrigus

Publications and source records attributed to I E Rodrigus.

At least 19 recordsLinked to original sources
PubMed2002

Effects of phosphodiesterase III inhibition on length-dependent regulation of myocardial function in coronary surgery patients.

BACKGROUND: Phosphodiesterase III inhibitors increase myocardial contractility and decrease left ventricular (LV) afterload. We studied whether these effects altered LV response to an increase in cardiac load and affected length-dependent regulation of myocardial function. METHODS: Before the start of cardiopulmonary bypass, a high-fidelity pressure catheter was positioned in the left ventricle and the left atrium in 10 coronary surgery patients. LV response to an increased cardiac load, caused by leg elevation, was assessed during baseline conditions and after administration of milrinone at a dose of 20 micrograms kg-1 over 15 min. Effects on contraction were measured by changes in maximal rate of pressure development (dP/dtmax). Effects on relaxation were assessed by analysis of changes in maximum rate of pressure decrease and by analysis of the load dependency of myocardial relaxation (R = slope of the relation between the time constant of isovolumic relaxation and end systolic pressure). RESULTS: Milrinone increased dP/dtmax but measures of relaxation were unaltered. Leg elevation had more effect on measures of contraction and relaxation after milrinone than at baseline. The relationship between R and changes in dP/dtmax shifted downwards and to the right with milrinone, whereas the relationship between R and changes in end diastolic pressure (EDP) shifted downwards and to the left. CONCLUSIONS: This suggests that milrinone improved contraction, reduced the load dependency of LV pressure decrease, and reduced the change in EDP after leg elevation.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2001

The effects of the pericardium on length-dependent regulation of left ventricular function in coronary artery surgery patients.

OBJECTIVE: To analyze the effects of the pericardium on the length-dependent regulation of myocardial function in coronary artery surgery patients. DESIGN: Prospective. SETTING: University hospital. PARTICIPANTS: Patients scheduled for elective coronary artery surgery. INTERVENTIONS: In 10 patients, a combined micromanometer transducer conductance catheter was inserted into the left ventricle for measurement of left ventricular pressures and volumes. MEASUREMENTS AND MAIN RESULTS: Consecutive data were obtained during a progressive increase in left ventricular pressures and volumes obtained by leg elevation in closed chest-closed pericardium and open chest-open pericardium conditions. Pericardiotomy did not alter baseline left ventricular hemodynamics. The effects of leg elevation were different, however. In closed chest-closed pericardium conditions, stroke volume and stroke work remained unchanged, whereas these parameters increased in open chest-open pericardium conditions. This increase was related to the increase in end-diastolic volume that was observed in open chest-open pericardium conditions and not in closed chest-closed pericardium conditions. CONCLUSIONS: In coronary artery surgery patients, pericardiotomy does not alter baseline left ventricular function. When cardiac load is increased by leg elevation, however, use of the Frank-Starling mechanism is enhanced in open chest-open pericardium conditions.

Coronary Vessels↗
PubMed2001

Effects of desflurane and sevoflurane on length-dependent regulation of myocardial function in coronary surgery patients.

BACKGROUND: Desflurane and sevoflurane have negative inotropic effects. The current study investigated whether these effects resulted in an altered left ventricular response to increased cardiac load and affected length-dependent regulation of myocardial function. Length-dependent regulation of myocardial function refers to the ability of the heart to improve its performance when preload is increased. METHODS: A high-fidelity pressure catheter was positioned in the left ventricle and left atrium in 20 coronary surgery patients with a preoperative ejection fraction greater than 40%. Studies were performed before the initiation of cardiopulmonary bypass. Left ventricular response to increased cardiac load, obtained by leg elevation, was assessed during control conditions and during increasing concentrations of desflurane (2, 4, and 6% end tidal; n = 10) or sevoflurane (1, 2, and 3% end tidal; n = 10). Effects on contraction were evaluated by analysis of changes in maximal rate of pressure development. Effects on relaxation were assessed by analysis of changes in minimum rate of pressure development and by analysis of the load dependence of myocardial relaxation (R = slope of the relation between time constant tau of isovolumic relaxation and end-systolic pressure). Peak left atrial-left ventricular pressure gradients were analyzed during early left ventricular filling. RESULTS: With both desflurane and sevoflurane, maximal and minimum rates of pressure development decreased while tau increased. Peak left atrial-left ventricular pressure gradients remained unchanged. The hemodynamic effects of leg elevation were similar at the different concentrations. Changes in parameters of contraction and relaxation during leg elevation were coupled and were not altered by desflurane or sevoflurane. CONCLUSIONS: Despite their negative inotropic and lusitropic effects, neither desflurane nor sevoflurane adversely affect length-dependent regulation of left ventricular function. In the conditions of our study, the ability of the left ventricular to respond to increased cardiac load is not altered by the use of desflurane or sevoflurane.

Aged↗
PubMed2001

Should we use video-assisted endoscopic vein harvesting as a standard technique?

BACKGROUND: To investigate the feasability and results of endoscopic vein harvesting (EVH) using the Vasoview Uniport system (Guidant Corporation, Menlo Park,CA). Can this technique be used as a standard technique for vein harvesting in coronary artery bypass surgery (CABG) or is it too time consuming? Do smaller incisions result in less morbidity and discomfort? METHODS: From October 1998 to May 1999, 158 patients who underwent CABG with venous grafts, in addition to arterial grafts, formed the study population for EVH. In group A (n=131) the vein was harvested with the Vasoview Uniport System. In group B (n=27) the vein was harvested by a conventional open technique with interrupted incisions because of unavailability of the equipment. Recordings were made on vein length, harvest time, length of incision, and complications. RESULTS: In none of the patients in group A was a conversion to the open technique necessary. In 72/131, pure EVH was used. In 59/131 an additional incision below the knee was used for harvesting extra vein length. Mean harvested vein graft length (cm) was 35.9 (range 18-56) in group A and 30.6 (range 16-51) in group B, and mm of vein harvested/min was 77 and 71 in group A and B. Mean time for harvesting and closing (min) was 56.1 (range 14-120) SD 20.4 and 78.3 (range 37-129) SD 26 for a mean length of incision (cm) of six (range 2-19) and 27 (range 12-54). Wound complications at postoperative day three at discharge, and after six weeks were seen in 30 (23%), 27 (20%) and four (4%) patients of group A, and in five (18%), five (18%) and four (23%) of group B. CONCLUSIONS: Despite a learning curve in using endoscopic techniques, the total procedural time for EHV is acceptable and even shorter than open harvesting. Most of the time is gained in closure of the wound. Hematoma formation is the most common peroperative complication, but diminishes with experience. The absence of postoperative edema after EVH is striking. Despite the higher costs for disposable material, we have adopted EVH as a standard technique since patient and surgeon satisfaction have improved substantially.

Adult↗
PubMed2000

Assessment of length-dependent regulation of myocardial function in coronary surgery patients using transmitral flow velocity patterns.

BACKGROUND: In a subset of coronary surgery patients, a transient increase in cardiac load by leg elevation resulted in a decrease in maximal rate of pressure development (dP/dtmax) and a major increase in end-diastolic pressure (EDP). This impairment of left ventricular (LV) function appeared to be related to a deficient length-dependent regulation of myocardial function. The present study investigated whether analysis of transmitral flow patterns with transesophageal echocardiography constituted a noninvasive method to identify these patients. METHODS: High-fidelity LV pressure tracings and transmitral flow signals were obtained in 50 coronary surgery patients during an increase in cardiac load by leg elevation. Using linear regression analysis, changes in transmitral E-wave velocity and deceleration time (DT) were related to changes in dP/dtmax and EDP. RESULTS: Changes in dP/dtmax with leg elevation were closely related to corresponding changes in E-wave velocity (r = 0.81; P < 0. 001) and to changes in DT (r = 0.78; P < 0.001). Similarly, changes in EDP were related to changes in E-wave velocity (r = 0.83; P < 0. 001) and to changes in DT (r = 0.84; P < 0.001). The decrease in dP/dtmax and the major increase in EDP in some patients was associated with an increase in E-wave velocity and a decrease in DT, indicating development of a restrictive LV filling pattern. CONCLUSIONS: Impairment of LV function with leg elevation was associated with the development of a restrictive transmitral filling pattern. Analysis of transmitral flow patterns by means of transesophageal echocardiography therefore allowed noninvasive identification of a subset of coronary surgery patients with impaired length-dependent regulation of LV function.

Blood Flow Velocity↗
PubMed1999

The effects of beta-adrenergic stimulation on the length-dependent regulation of myocardial function in coronary surgery patients.

UNLABELLED: Increasing cardiac load by leg elevation identifies patients with load-dependent impairment of left ventricular (LV) function. This impairment is related to a deficient length-dependent regulation of LV function. We investigated the effects of dobutamine on length-dependent regulation of LV function in coronary surgery patients (n = 25). High-fidelity LV pressure tracings were obtained at end-expiration, while hearts were paced at a fixed rate of 90 bpm. Effects of leg elevation on contraction and relaxation were compared before and during dobutamine 5 microg x kg(-1) x min(-1). Effects on contraction were evaluated by analysis of changes in dP/dtmax. Effects on relaxation were assessed by analysis of R (slope of the relation between the time constant of isovolumic relaxation and end-systolic pressure). Correlations were calculated with linear regression analysis using Pearson's coefficient r. The effects of leg elevation on variables of contraction and relaxation were coupled. We found a close relationship between changes in dP/dtmax and individual values of R (r = 0.84; P < 0.001). Dobutamine improved myocardial function and accelerated LV pressure decrease. Under dobutamine, the increase in dP/dtmax with leg elevation was larger (P < 0.001) and load dependence of LV relaxation was reduced (P = 0.001). Dobutamine improved the effects of leg elevation on LV function, reflecting improved length-dependent regulation of LV function. IMPLICATIONS: This study demonstrated that beta-adrenoreceptor stimulation with dobutamine improved length-dependent regulation of myocardial function assessed during leg elevation in cardiac surgical patients.

Adrenergic beta-Agonists↗
PubMed1999

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 relaxation.

Aged↗
PubMed1999

Spontaneous dissection of three major coronary arteries subsequent to cystic medial necrosis.

This case report describes the devastating consequences of spontaneous coronary dissection in a 36-year-old female patient. Surgical revascularization was attempted, but diffuse myocardial infarction developed. The patient was bridged to heart transplantation but died secondary to multiple organ failure. To our knowledge, this is the only reported case of spontaneous dissection of the three main coronary arteries due to severe cystic medial necrosis.

Adult↗
PubMed1998

Primary repair of coronary sinus injury caused by direct cutdown.

We report on a iatrogenic perioperative injury to the coronary sinus. Although oversewing venous bleeding sites on the heart usually resolves the problem, this caused an enormous venous engorgement of the posterior and apical regions of the heart, which prompted us to direct primary suture of the coronary sinus incision. A brief literature review with possible suggestions for solving this problem is given.

Aged↗
PubMed1997

Effects of calcium on left ventricular function early after cardiopulmonary bypass.

OBJECTIVES: Evaluation of the effects of intravenous CaCl2 on systolic and diastolic function early after separation from cardiopulmonary bypass (CPB) DESIGN: Prospective study SETTING: University hospital PARTICIPANTS: Twenty patients scheduled for elective coronary artery surgery INTERVENTIONS: Left ventricular (LV) pressures were measured with fluid-filled catheters. Data were digitally recorded during pressure elevation induced by tilt-up of the legs. Transgastric short-axis echocardiographic views of the LV were simultaneously recorded on videotape. Measurements were obtained before the start of CPB, 10 minutes after termination of CPB, after intravenous administration of CaCl2, 5 mg/kg, and 10 minutes later. MEASUREMENTS AND MAIN RESULTS: Systolic function was evaluated with the slope (Ees, mmHg/mL) of the systolic pressure-volume relation. Diastolic function was evaluated with the chamber stiffness constant (Kc, mmHg/mL) of the diastolic pressure-volume relation. CaCl2 increased Ees from 2.62 +/- 0.46 to 5.58 +/- 0.61 (mean +/- SD), but induced diastolic dysfunction with an increase in Kc from 0.011 +/- 0.006 to 0.019 +/- 0.007. These changes were transient and had disappeared within 10 minutes after administration of CaCl2. CONCLUSIONS: CaCl2 early after CPB transiently improved systolic function at the expense of an increase in ventricular stiffness, suggesting temporary diastolic dysfunction.

Adult↗
PubMed1997

Effects of lidoflazine on left ventricular function in patients.

OBJECTIVE: The present study evaluated the effects of the nucleoside transport inhibitor, lidoflazine, at a dose of 1 mg/kg, on left ventricular function. DESIGN: Patients were randomly assigned to receive either lidoflazine or saline in a double-blind manner. SETTING: A university hospital. PARTICIPANTS: The study was performed in 32 patients scheduled for elective coronary artery bypass surgery. INTERVENTIONS: Left ventricular pressures were measured with fluid-filled catheters. Data were digitally recorded during pressure elevation induced by tilt-up of the legs. Transgastric short-axis echocardiographic views of the left ventricle were simultaneously recorded on videotape. Systolic function was evaluated with the slope (Ees, mmHg/mL) of the systolic pressure-volume relationship. Diastolic function was evaluated with the chamber stiffness constant (Kc, mmHg/mL) of the diastolic pressure-volume relationship. Cardiac function was assessed at baseline and after administration of either lidoflazine (group A [n = 16]) or placebo (group B [n = 16]). Data were compared using two-factor analysis of variance. MEASUREMENTS AND MAIN RESULTS: At baseline, diastolic and systolic function were comparable in both groups. Lidoflazine increased Kc from 0.079 +/- 0.015 to 0.125 +/- 0.017 mmHg/mL and decreased Ees from 2.481 +/- 0.213 to 1.217 +/- 0.211 mmHg/mL (p = 0.009 and p = 0.004, respectively). None of these changes occurred when placebo was administered. CONCLUSIONS: Administration of lidoflazine before the start of cardiopulmonary bypass impaired left ventricular systolic function but also increased diastolic stiffness.

Aged↗
PubMed1997

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 drive.

Adrenergic beta-Agonists↗
PubMed1996

Biventricular assist for severe acute rheumatic pancarditis.

Severe heart failure in acute rheumatic myocarditis is rare. It may be rapidly reversible with treatment, so maximal medical treatment and, if necessary, mechanical support should be given before heart transplantation is considered.

Acute Disease↗
PubMed1996

Recovery of systolic and diastolic left ventricular function early after cardiopulmonary bypass.

BACKGROUND: Impairment of left ventricular function after cardiopulmonary bypass (CPB) is well recognized, but little is known about the time course of recovery of cardiac function early after separation from CPB. Therefore, recovery of left ventricular function was evaluated early after separation from CPB in patients undergoing coronary artery surgery. The authors tried to determine whether this recovery might be attributed to autoregulation of function by preload. METHODS: Left ventricular pressure was measured with fluid-filled catheters. Data were digitally recorded during increased pressure induced by elevating the legs. Transgastric short-axis echocardiographic views of the left ventricle were simultaneously recorded on videotape. Systolic function was evaluated with the slope (Ees, mmHg/ml) of the systolic pressure-volume relation. Diastolic function was evaluated with the chamber stiffness constant (Kc, ml-1) of the diastolic pressure-volume relation. Cardiac function was assessed before CPB, after termination of CPB, and 5, 10, and 15 min later. Two different separation procedures from CPB were compared: in protocol 1, left ventricular function was documented during the standard procedure (n = 24); in protocol 2, the heart was optimally filled 10 min before separation from CPB (n = 12). RESULTS: In protocol 1, Ees was 2.88 +/- 0.21 mmHg/ml (mean +/- SEM) and Kc was 0.012 +/- 0.001 ml-1 before CPB. Within 10 min after separation from CPB, Ees increased from 1.10 +/- 0.32 to 2.92 +/- 0.34 (P = 0.001) and Kc decreased from 0.022 +/- 0.002 to 0.011 +/- 0.001 (P = 0.001). The parameters remained stable thereafter. In protocol 2, Ees was 2.92 +/- 0.51 mmHg/ ml and Kc was 0.011 +/- 0.002 ml-1 before CPB. Depression of systolic and diastolic function was not observed in these patients. At time 0, Ees was 2.46 +/- 0.16 and Kc was 0.012 +/- 0.002. These values remained stable throughout the entire observation period. CONCLUSIONS: Significant functional recovery was observed early after separation from CPB, which was suggestive of time-dependent changes in both systolic and diastolic left ventricular function induced by preload restoration.

Anesthesia↗
PubMed1996

Efficacy and safety of aprotinin in aortocoronary bypass and valve replacement operations: a placebo-controlled randomized double-blind study.

To assess the efficacy and safety of the use of a high-dose regimen of aprotinin in routine cardiac operations, a placebo-controlled randomized double-blind study was conducted in 93 adult patients undergoing cardiopulmonary bypass. Aprotinin-treated patients (group A, n = 46) received 2 x 10(5) Kallikrein Inactivating Units (KIU) of aprotinin before incision, 2 x 10(6) KIU in the priming solution and 5 x 10(5) KIU/h during CPB. Control patients (group B, n = 47) received the same volume of normal saline. Mean postoperative blood loss in ml after six hours and in total until removal of thoracic drains decreased significantly from 752 and 1933 in controls, to 358 and 1051 in treated patients (p < 0.001). Mean total transfusion needs were 2.6 (A) and 4.8 (B) units per patient. Adverse events were evenly distributed between both groups and could not be attributed to aprotinin use. We, therefore, recommend the use of a high-dose regimen of aprotinin for routine cardiac operations despite its cost.

Adult↗
PubMed1995

Colour duplex scanning versus angiography: a retrospective assessment of carotid stenosis.

A retrospective study was performed to investigate the reliability of colour duplex scanning as a screening method in detecting carotid artery disease. The results of this technique and digital subtraction arteriography of 100 carotid bifurcations in 50 patients undergoing carotid endarterectomy were compared. In accordance with suggested standard reports dealing with cerebrovascular disease, the diameter reduction was classified in one of five categories: < 20%, 20-59%, 60-79%, 80-99% and total occlusion. In 78% the gradings determined using digital subtraction arteriography and duplex scanning correlated perfectly, and in 99% of the studied bifurcations the difference was not more than one grade. The sensitivity and specificity of colour duplex scanning in detecting a stenosis with a diameter reduction of more than 60% was 98% and 87.7%, respectively. The best non-invasive method to identify carotid bifurcation disease is duplex scanning. Although the role of duplex scanning as an alternative to angiography is currently evolving, the authors still advocate carotid angiography when surgery is considered.

Aged↗