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Results for “Ventricular Function, Right”

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At least 55 records · Page 3Linked to original sources

PubMed2002

Post-resuscitation right ventricular dysfunction: delineation and treatment with dobutamine.

BACKGROUND: Left ventricular dysfunction after resuscitation from cardiac arrest has been well described. Treatment with dobutamine improves post-resuscitation left ventricular function. Right ventricular function following resuscitation has not been investigated. The purposes of this study were to examine right ventricular function following resuscitation and determine whether dobutamine would improve post-resuscitation right ventricular function. METHODS AND RESULTS: Right ventricular function was measured in 28 swine (29+/-1 kg) before and after resuscitation from 15 min of untreated ventricular fibrillation. Twelve animals received dobutamine at 10 mcg/kg/min while 16 animals served as untreated controls. Among controls, right ventricular dysfunction post-resuscitation was demonstrated by a decrease in right ventricular ejection fraction and an increase in right ventricular end-diastolic pressure. Among animals treated with dobutamine, there was a significant improvement in right ventricular function post-resuscitation compared to untreated controls. CONCLUSIONS: This study establishes that right ventricular systolic and diastolic dysfunction does occur after prolonged cardiac arrest from ventricular fibrillation. Dobutamine can ameliorate post-resuscitation right ventricular dysfunction.

Animals↗

PubMed2000

Improved right ventricular function after intracoronary administration of a C1 esterase inhibitor in a right heart transplantation model.

OBJECTIVE: Myocardial injury from ischemia can be augmented after reperfusion due to proinflammatory events including complement activation, leukocyte adhesion, and release of various chemical mediators. It has been shown that intracoronary administration of a C1 esterase inhibitor (C1 INH) significantly reduces myocardial necrosis in an experimental model of ischemia. Our study addresses the question whether the most susceptible region of the heart for ischemic injury, the right ventricle (RV), can benefit from the protective effects of C1 esterase inhibition after transplantation. METHODS: To precisely control RV volume in vivo an isovolumic model was used in which the RV volume was regulated using an intracavity high compliance balloon inserted into donor hearts of domestic pigs (34+/-4 kg). After 4 h of ischemia, donor hearts were transplanted into recipient pigs (44+/-4 kg). Treatment groups, each with six animals, consisted of C1 INH treatment or control. After opening the cross clamp, the C1 INH group animals received 20 IU/kg body weight of C1 INH intracoronary over a 5 min period. The control animals received no drug therapy. The hearts were reperfused for 60 min, and thereafter the RV balloon volume was increased in 10 ml increments until RV failure occurred. These measurements were repeated after 120 min of reperfusion. RESULTS: There was no significant difference in maximal RV developed pressure between the two groups (after 1 h, 35.7+/-5.9 vs. 40.6+/-12.7 mm Hg; after 2 h, 41.5+/-10.7 vs. 46.3+/-15.2 mm Hg; for C1 INH and control animals, respectively). However, the RV could be loaded with a significantly higher volume after both 1 h (60.0+/-20.0 ml (C1 INH) vs. 46.7+/-13.7 ml (control) balloon volume, P<0.05), and 2 h of reperfusion (70.0+/-8.9 ml vs. 60.0+/-6.3 ml; C1 INH and control animals, respectively; P<0.05). CONCLUSIONS: Intracoronary administration of a C1 INH significantly improves right ventricular function in an experimental transplant model. Thus, inhibition of the classic complement cascade may be a promising therapeutic approach for effective protection of myocardium from reperfusion injury after transplantation.

Animals↗

PubMed2005

[Evaluation of right ventricular function by tissue Doppler echocardiography and Tei index in right ventricular myocardial infarction].

OBJECTIVE: With tissue Doppler imaging and right ventricular Tei index, right ventricular function in patients with right ventricular myocardial infarction (RVMI) was assessed. METHOD: 51 patients admitted to coronary care units and diagnosed as acute inferior myocardial infarction were further studied with the ECG criterion of ST segment elevation >or= 1mm in V(4R) to establish the diagnosis of RVMI. 23 patients were thus diagnosed as RVMI and 28 patients not. 20 healthy subjects served as controls. Clinical and echocardiography index were recorded. Peak systolic and peak early and late diastolic velocities (Sm, Em, Am) and Em/Am were acquired from the apical four-chamber view at the lateralside of tricuspid annulus, the septal side of the tricuspid annulus and the RV free mid-wall using DTI. Interval between tricuspid closing and reopening and ejection time (ET) from parasternal short-axis view were recorded by pulse-wave Doppler. RV Tei index was calculated. RESULTS: Sm and Em at the lateral side of tricuspid annulus and the RV free mid-wall reduced significantly in patients with RVMI as compared with those without RVMI and healthy individuals (Sm at the lateral (7.0 +/- 2.0) cm/s vs (8.7 +/- 1.9) cm/s and (10.6 +/- 2.1) cm/s, P < 0.01; Em at the lateral (6.3 +/- 1.9) cm/s vs (7.9 +/- 1.8) cm/s and (9.6 +/- 1.9) cm/s, P < 0.01; Sm at the RV free mid-wall (6.4 +/- 1.9) cm/s vs (8.0 +/- 1.9) cm/s and (9.4 +/- 2.0) cm/s, P < 0.05; Em at the RV free mid-wall (6.1 +/- 2.0) cm/s vs (7.6 +/- 2.0) cm/s and (9.2 +/- 2.3) cm/s, P < 0.05). RV Tei index in patients with RVMI also increased as compared with that in the other two groups (0.65 +/- 0.19 vs 0.40 +/- 0.15 and 0.26 +/- 0.10; P < 0.01). CONCLUSIONS: The evaluation of velocities at the lateral side of tricuspid annulus and the RV free mid-wall using DTI and RV Tei index provides a noninvasive and rapid method for assessing right ventricular function in patients with RVMI.

Adult↗

PubMedDate not supplied

Chronic effect of left ventricular assist pumping on right ventricular function.

We evaluated right ventricular (RV) function during left ventricular assist device (LVAD) pumping during acute and chronic experiments in both normal hearts and hearts with left ventricular failure. An LVAD was implanted between the left atrium and the descending aorta of goats. The LVAD was pumped in a counterpulsation mode and at maximum bypass flow for 4-6 weeks in chronic experiments. The following results were obtained: 1) LVAD pumping itself did not affect RV function, even after 6 weeks of pumping, 2) the dimensions of the RV free-wall segments measured by sonomicrometers showed a gradual and small increase during the early postoperative days, which was due to an increase in volume returned to the RV and the deformity of the RV cavity derived from reduction in LV volume, and 3) the same tendencies were seen even with LV failure hearts. These results suggested that 1) LVADs can assist not only the LV but also the RV by reducing RV afterload, 2) excessive and prolonged assistance by an LVAD seems to dilate the RV free-wall, and 3) preexisting RV dysfunction is the main cause of signs of RV failure during LV pumping.

Animals↗

PubMed2004

Plasma B-type natriuretic peptide levels in systolic heart failure: importance of left ventricular diastolic function and right ventricular systolic function.

OBJECTIVES: This study was designed to characterize the importance of echocardiographic indexes, including newer indexes of diastolic function, as determinants of plasma B-type natriuretic peptide (BNP) levels in patients with systolic heart failure (SHF). BACKGROUND: Plasma BNP levels have utility for diagnosing and managing heart failure. However, there is significant heterogeneity in BNP levels that is not explained by left ventricular size and function alone. METHODS: In 106 patients with symptomatic SHF (left ventricular ejection fraction [LVEF] <0.35), we measured plasma BNP levels and performed comprehensive echocardiography with assessment of left ventricular diastolic function, including color M-mode (CMM) and tissue Doppler imaging (TDI), and of right ventricular (RV) function. RESULTS: Median plasma BNP levels were elevated and increased with greater severity of diastolic dysfunction. We found significant correlations (p < 0.001 for all) between BNP and indexes of myocardial relaxation (early diastolic velocity: r = -0.26), compliance (deceleration time: r = -0.55), and filling pressure (early transmitral to early annular diastolic velocity ratio: r = 0.51; early transmitral flow to the velocity of early left ventricular flow propagation ratio: r = 0.41). In multivariate analysis, overall diastolic stage, LVEF, RV systolic dysfunction, mitral regurgitation (MR) severity, age and creatinine clearance were independent predictors of BNP levels (model fit r = 0.8, p < 0.001). CONCLUSIONS: Plasma BNP levels are significantly related to newer diastolic indexes measured from TDI and CMM in SHF. Heterogeneity of BNP levels in patients with SHF reflects the severity of diastolic abnormality, RV dysfunction, and MR in addition to LVEF, age, and renal function. These findings may explain the powerful relationship of BNP to symptoms and prognosis in SHF.

Aged↗

PubMed1993

Effects of exercise or temporary coronary occlusion during angioplasty on right ventricular function with consideration of left-anterior-descending- and right-coronary-artery-related myocardial ischemia.

Whether exercise causes right ventricular ischemia severe enough to depress right ventricular function is still controversial. Therefore, right ventricular function was evaluated in 44 patients with isolated coronary artery disease of either the proximal left anterior descending or right coronary artery during exercise (n = 22) or balloon occlusion during percutaneous transluminal coronary angioplasty (PTCA) (n = 22). Central hemodynamics and right ventricular volumes were determined using a new thermodilution Swan-Ganz catheter. Exercise increased right ventricular end-diastolic volume index [from 89 (66-127) to 101 (70-130) ml m-2, p = 0.00005; median (range)] and stroke volume index [from 44 (27-68) to 53 (36-75) ml m-2, p = 0.0005]. During PTCA, right ventricular end-diastolic volume index remained unchanged, while stroke volume index decreased from 49 (38-60) to 40 (26-49) ml m-2 (p = 0.00005). The decrease in right ventricular ejection fraction during exercise from 56 (41-64) to 52% (39-64) reached only borderline significance (p = 0.06) and was significantly (p = 0.02) smaller than during angioplasty [from 53 (44-62) to 41% (25-66; p = 0.0008)]. Right ventricular ejection fraction did not differ between left anterior descending or right coronary artery obstruction and did not depend on right ventricular afterload. In comparison to exercise angioplasty caused a decreased systolic pressure-volume ratio and a leftward shift of the diastolic pressure-volume curve. In conclusion, exercise has only little effect on right ventricular ejection fraction, whereas inadequate oxygen supply during balloon angioplasty induces severe depression of right ventricular function.

Adult↗

PubMed1994

Selective positive end-expiratory pressure and right ventricular function in dogs.

Differential ventilation with selective positive end-expiratory pressure (PEEP) has been shown to reduce cardiac output less than general PEEP. In previous studies we have demonstrated that during selective PEEP left ventricular preload is better maintained than during general PEEP. The present study was designed to determine whether the different haemodynamic responses to selective and general PEEP also might be due to different effects on RV preload. The study was performed on nine acutely instrumented dogs, in which extraventricular pressure was measured by pericardial balloon transducers. Measures of RV preload were obtained by the use of ultrasonic segment length transducers as well as end-diastolic transmural pressure (RVEDP). The study showed reductions in RVEDP during general and selective right (R) PEEP, accompanied by moderate reductions in RV inflow tract segment lengths. These changes were most marked with general PEEP. Selective LPEEP did not change RV preload significantly. Therefore, better maintained cardiac output with selective PEEP than with general PEEP is partly due to less impairment of right ventricular filling.

Animals↗

PubMed1991

Pulmonary vasodilatation and augmentation of right ventricular function following terbutaline infusion in severe chronic pulmonary disease.

Twenty patients with a median age of 61 years and a median forced expired volume in 1 s (FEV1) after bronchodilating therapy of 0.55 l were studied in order to measure the effect of intravenous terbutaline on bronchial tone, cardiac function, pulmonary haemodynamics, gas exchange, and oxygen transport capacity during rest and in 10 patients during exercise. Terbutaline infusion during rest resulted in an increase in heart rate from 84 to 103 beats min-1 (P less than 0.01), a decrease in mean systemic arterial pressure from 95 to 80 mmHg (P less than 0.02), an unchanged mean pulmonary arterial pressure (18 mmHg), an increase in cardiac index from 2.89 to 3.86 l min-1 m-2 (P less than 0.01), an increase in right ventricular ejection fraction from 45 to 53% (P less than 0.01), an increase in left ventricular ejection fraction from 63 to 67% (NS), an unchanged arterial oxygen tension, and an increase in calculated oxygen delivery from 533 to 638 ml O2 min-1 m-2 (P less than 0.01). During exercise terbutaline infusion resulted in an increase in heart rate from 108 to 120 beats min-1 (P less than 0.05), a decrease in mean systemic arterial pressure from 117 to 106 mmHg (P less than 0.01), a decrease in mean pulmonary arterial pressure from 29 to 22 mmHg (P less than 0.01), an increase in cardiac index from 4.53 to 4.64 min-1 m-2 (NS), an unchanged arterial oxygen tension, and an increase in the calculated oxygen delivery from 834 to 856 ml O2 min-1 m-2 (NS). It was concluded that terbutaline augments right ventricular function: increases right ventricular ejection fraction and decreases right ventricular end-diastolic volume, and further decreases pulmonary vascular resistance without decreasing arterial oxygen tension, and increases oxygen delivery in patients with chronic pulmonary disease during rest and exercise.

Aged↗

PubMed1992

Clinical evaluation of right ventricular function in patients with left ventricular assist device (LVAD).

Right ventricular function (RVF) during LVAD support can be a threat for patient survival. Despite extensive research, RVF and its interference with left heart function is unclear. This study examines RVF in a retrospective analysis of 14 patients. Hemodynamic data were collected, including heart rate (HR), central venous pressure (CVP), mean pulmonary artery pressure (mPAP), total cardiac output (CO), calculated stroke volume index (SVI) and right ventricular stroke work index (RVSWI). In all patients, CO increased gradually throughout the study period; CVP showed no significant decrease; mPAP and PCWP decreased significantly over the time period; SVI improved and RVSWI increased from the starting level prior to implantation of the LVAD. We conclude that the CO improved with a lowering of the right ventricular afterload combined with a decrease in total circulating volume. The improvement of RVF with LV assist makes this device an option as a bridge to transplant.

Blood Pressure↗

PubMed1988

Echocardiographic assessment of cardiac function during respiratory syncytial virus infection.

Respiratory syncytial virus infection has been associated with increased morbidity and mortality in infants with underlying cardiac and pulmonary disease. To understand better the cardiopulmonary interaction in patients with acute respiratory syncytial virus bronchiolitis, we performed M-mode echocardiograms and pulsed Doppler assessment of pulmonary arterial flow in 19 patients with structurally normal hearts during acute illness. Studies were repeated in 11 of these patients following complete recovery. Based on severity of respiratory compromise, patients were grouped into those with severe illness (ten patients) or mild illness (nine patients). Left ventricular dimensions and shortening fraction were used to assess left ventricular function. Right ventricular systolic time intervals and specific Doppler flow velocity measurements were used to assess right ventricular function and elevation of pulmonary artery pressure. Comparisons were made between patients with severe and mild illness and between acute and follow-up studies. No statistically significant differences in left ventricular function, right ventricular systolic time intervals, or Doppler flow measurements were observed. We conclude that in patients with structurally normal hearts, respiratory syncytial virus bronchiolitis is not associated with significant depression of cardiac performance or elevation in pulmonary resistance.

Bronchiolitis, Viral↗

PubMed2006

Feasibility and accuracy of a routine echocardiographic assessment of right ventricular function.

The evaluation of right ventricular (RV) systolic function is important for its clinical and prognostic value but difficult to obtain due to RV complex anatomy. Aims of this study were to evaluate the feasibility of a routine use of RV fractional shortening area (FSA), systolic excursion (TAPSE) and peak systolic velocity (PSV) of tricuspidal annular motion in a large series of cases (900 pts), to determine the values in normal subjects (150) and in patients (750) with different pathologies and to correlate these indexes to clinical and echo-Doppler variables. FSA (50.3+/-10% vs 54.6+/-9% p<0.01), TAPSE (20.2+/-5 vs 24.7+/-4 mm, p<0.01) and PSV (16.2+/-4 vs 20+/-4 cm/s, p<0.01) were lower in patients than in normals, correlated positively to left ventricular ejection fraction and negatively to the pulmonary pressure. The values of 17 mm for TAPSE, 12 cm/s for PSV and 37% for FSA identified patients with high specificity. The values in subgroups of pathological patients were evaluated and compared.

Echocardiography, Doppler↗

PubMed1997

Myocardial cooling and right ventricular function in patients with right coronary artery disease: antegrade vs. retrograde cardioplegia.

BACKGROUND: Protection of the right ventricular (RV) myocardium during ischaemia in cardiac surgery is difficult, especially in patients with severe right coronary artery (RCA) disease. Retrograde coronary sinus cardioplegia is thought to distribute uniformly, but doubts still remain as to its adequacy in RV preservation. This study evaluated distribution of antegrade vs. exclusively retrograde coronary sinus cold blood cardioplegia by assessing myocardial cooling and compared the effects on RV function. METHODS: Fifty-eight patients scheduled for elective coronary artery surgery-29 patients with significant RCA disease and another 29 with no significant RCA stenosis (controls)-were randomised to receive either antegrade or retrograde cold blood cardioplegia through either aortic root or conventional self-inflating coronary sinus catheter (RCA-ante, RCA-retro, C-ante and C-retro groups). RV function was assessed by fast-response thermodilution. Myocardial temperatures were measured in the anterior and posterior wall of the right and left ventricle. RESULTS: Cooling of the posterior wall of the RV was effective only in the control patients given antegrade cardioplegia (14.7 degrees C), whereas in the other groups the lowest myocardial temperatures there remained above 20 degrees C (P < 0.001). In patients with obstructed RCA both antegrade and retrograde cold cardioplegia led to uneven cooling of the myocardium. After cardiopulmonary bypass the RV ejection fraction (RVEF), RV stroke work index (RVSWI) and cardiac index (CI) were significantly reduced in the RCA-retro group, and RVSWI and CI in the C-retro group, too. Regression analysis showed an inverse relationship between the temperatures of the posterior walls of the ventricles and changes in the RVEF and CI. CONCLUSIONS: Retrograde and antegrade cardioplegia alone were not effective in reducing the temperature of the posterior wall of the RV in the patients with obstructed RCA, in whom with retrograde cardioplegia RV haemodynamics were impaired for 1 hour following bypass. Neither retrograde nor antegrade cardioplegia alone can be relied on to protect the posterior wall of the RV in the patients with obstructed RCA.

Anesthesia↗

PubMedDate not supplied

The use of gated radionuclide ventriculography as a noninvasive method of evaluating right ventricular function in dogs with experimentally induced congestive heart failure.

Gated radionuclide ventriculography was evaluated as a noninvasive method of quantifying right ventricular function in dogs with experimentally induced congestive heart failure. Gated radionuclide ventriculography measurements of right ventricular function (right ventricular ejection fraction, right ventricular average emptying rate, and right ventricular average filling rate) were related to standard hemodynamic and echocardiographic measurements. Congestive heart failure was induced by rapid ventricular pacing in eight normal dogs. Hemodynamic, echocardiographic, and gated radionuclide ventriculography measurements were obtained before and after development of biventricular failure. Congestive heart failure resulted in significant changes in all hemodynamic, echocardiographic, and gated radionuclide ventriculography measurements with the exception of systemic arterial pressure. Right ventricular ejection fraction was inversely related to pulmonary artery systolic, diastolic, and mean pressure, and right ventricular average emptying rate was inversely related to the pulmonary artery systolic, diastolic, and mean pressure. Right ventricular ejection fraction was inversely related to left ventricular filling pressure, (pulmonary capillary wedge pressure). Neither the echocardiographic measurements of right ventricular size (right ventricular internal diastolic dimension) nor the right ventricular end-diastolic pressure were related to right ventricular ejection fraction and right ventricular average emptying rate. However, echocardiographic measurements of right ventricular dimension were related to right ventricular filling pressure. The gated radionuclide ventriculography indexes of right ventricular function, right ventricular ejection fraction and right ventricular average emptying rate, are affected by afterload but unaffected by preload, whereas the echocardiographic measurement of right ventricular dimension is related to preload. Gated radionuclide ventriculography provides right ventricular data which is unique from that obtained by standard echocardiographic imaging. Also, gated radionuclide ventriculography has potential value as a noninvasive means of estimating a change in pulmonary artery pressure.

Animals↗

PubMed1983

Right ventricular function in Chagas disease.

To study right ventricular function, we performed cardiac catheterization, and right and left cineventriculograms in 60 chagasic patients and 15 non-chagasic, non-heart disease patients. Chagasic patients with normal electrocardiograms and left cineventriculograms also had normal right ventricular function. Nine of 14 chagasic patients with normal Ecg's and early left ventricular damage had right ventricular dilatation and/or segmental inferior-apical asynergy. Fourteen of 19 chagasic patients with abnormal Ecg's and advanced left ventricular damage, but without signs of congestive heart failure, and all chagasic patients with congestive heart failure, had marked right ventricular dilatation, severe right contractility depression and abnormal right apical or para-apical motion. These findings indicate that Chagas disease is a diffuse cardiomyopathy in which the left ventricle seems to be affected earlier and to a greater extent than the right ventricle. Since segmental abnormalities were predominantly observed in apical and para-apical areas of the ventricles, performance of right and left cineventriculograms is recommended before implantation of cardiac pacemakers.

Adult↗

PubMed1992

Effects of acute, transient coronary occlusion on global and regional right ventricular function in humans.

OBJECTIVES: The aim of this study was to investigate the changes in right ventricular function during acute coronary occlusion produced by inflating a coronary angioplasty balloon catheter. BACKGROUND: Alterations in right ventricular function are well known to occur in patients with acute myocardial infarction or ischemic cardiomyopathy. However, the changes in right ventricular function resulting from acute, transient coronary occlusion of each of the major coronary arteries have been scantily studied, perhaps because of serious limitations of currently available technology. METHODS: A newly designed, mobile, multiwire gamma camera, in combination with generator-produced tantalum-178, affords high count rate first-pass radionuclide angiography and is thus ideal for studying right ventricular function at the bedside. Accordingly, 46 patients underwent first-pass radionuclide angiography at baseline and during transient coronary occlusion induced by a coronary angioplasty balloon catheter. RESULTS: A significant, albeit modest, decrease in global right ventricular ejection fraction occurred during occlusion of the left anterior descending (from 42.9 +/- 9.3% to 39 +/- 8.7%, p < 0.05) and left circumflex (from 44 +/- 9.1% to 38.8 +/- 7.9%, p = 0.03) coronary arteries, but diagonal artery occlusion caused no significant change in right ventricular ejection fraction. Occlusion of the right coronary artery proximal (but not distal) to the acute marginal branch caused a significant decrease in right ventricular ejection fraction (from 42.6 +/- 4.7% to 35.7 +/- 7.2%, p < 0.01). Although occlusion of the left anterior descending, left circumflex and proximal right coronary arteries all caused significant deterioration in regional right ventricular function, only proximal right coronary occlusion caused right ventricular dilation (p < 0.005). CONCLUSIONS: Significant impairment of right ventricular function occurs during transient occlusion of the left anterior descending, left circumflex and proximal right coronary arteries, but only occlusion of the latter causes acute right ventricular dilation, probably as a result of ischemia.

Adult↗

PubMed1995

Right ventricular function after coronary artery bypass grafting in patients with and without revascularization of the right coronary artery.

OBJECTIVES: To evaluate the influence of revascularization of a stenosis of the right coronary artery on right ventricular function. DESIGN: Prospective study. SETTING: Single institutional study in a university hospital. PARTICIPANTS: 20 patients with different degrees of stenosis of the right coronary artery undergoing elective coronary artery bypass grafting. INTERVENTIONS: In 10 patients, bypass surgery included revascularization of a significant stenosis of the right coronary artery (group 1). In 10 other patients, the pathology of the right coronary artery was judged to be not significant, without indication for revascularization (group 2). MEASUREMENTS AND MAIN RESULTS: Using the fast-response thermodilution pulmonary artery catheter, right ventricular function was estimated perioperatively. After termination of extracorporeal circulation, there was an increase in right ventricular volumes in group 2 (p < 0.05) and an initial decrease in group 1 (p < 0.05), with higher volumes in group 2 compared with group 1 (p < 0.05). The ejection fraction increased in group 1 (p < 0.05) and decreased in group 2 after operation (p < 0.05), with higher values in group 1 compared with group 2 (p < 0.05). In addition to these findings, the pressure-volume relationship showed a leftward and upward shift in group 1 and a rightward shift in group 2 postoperatively. CONCLUSIONS: These results indicate that right ventricular depression can occur after bypass grafting in patients with a moderate stenosis of the right coronary artery that is not revascularized. Revascularization of more severe stenosis of the right coronary artery appears to preserve postoperative right ventricular function.

Cardiac Volume↗

PubMed1995

Effects of dynamic cardiomyoplasty on right ventricular function.

This study was planned to document the right ventricular function immediately after cardiomyoplasty. Right ventricular volumes were calculated with the use of fast response thermistor. Right ventricular end-diastolic volume was reduced from 91 +/- 8 mL/M2 to 75 +/- 7 mL/M2 (p < 0.05) and right ventricular end-systolic volumes increased from 51 +/- 5 mL/M2 to 59 +/- 4 mL/M2 24 hours after the operation. Central venous pressure was raised from 2 +/- 1 to 9 +/- 3 mm H2O. These changes were interpreted as impairment of the right ventricular diastolic function. Cardiac index raised from 1.8 +/- 0.5 L/M2 per minute to 2.7 +/- 0.3 L/m2 per minute within a period of 7 days (p < 0.05). As a result of this study, we concluded that preoperatively normal right ventricular function deteriorates after the cardiomyoplasty. In the intensive care unit volume balance must be carefully monitored to avoid creating right ventricular dysfunction.

Adult↗

PubMed2002

Determinants of maximal right ventricular function: role of septal shift.

BACKGROUND: Right heart failure can occur after orthotopic heart transplantation and can complicate implantation of left ventricular assist devices. The functional codeterminants of right ventricular function are not fully understood. We investigated the effects of left ventricular preload and afterload, systemic pressure, and the contribution of the interventricular septum to right ventricular function. METHODS AND RESULTS: In vivo studies were conducted in 12 dogs by using a highly defined, isovolumic right heart preparation. At any given arterial pressure, maximal right ventricular developed pressure was not influenced by left heart output; however, right ventricular volumes at which peak right ventricular developed pressure occurred differed significantly between the volume-loaded versus the unloaded left ventricle (P <.05). A correlation was found between peak right ventricular developed pressure and mean arterial pressure. The shift of the interventricular septum toward the left ventricle is delayed under the influence of left ventricular volume load, but the maximal interventricular septal deformation does not differ at maximal right ventricular developed pressure. There was a substantial and significant decrease in peak right ventricular developed pressure when the interventricular septum was inactivated (P <.05). CONCLUSIONS: Right ventricular function has multiple determinants, including the right ventricular free wall, the left ventricle, and the interventricular septum. Changes in right ventricular performance caused by alterations in left ventricular volume load and mean arterial pressure are mediated partially through the interventricular septum, as well as through perfusion of the right ventricular free wall; inactivation of the interventricular septum leads to a significant decrease in right ventricular function. Maintaining left ventricular developed pressure and hence the contribution of the interventricular septum to right ventricular function may be important in the management of right ventricular failure.

Animals↗