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PubMed1992

Evaluation of right ventricular function by regional wall motion analysis in patients after correction of tetralogy of Fallot. Comparison of transventricular and nontransventricular repairs.

Right ventricular function was assessed by regional wall motion analysis and by global function in 62 patients after repair for tetralogy of Fallot. Its relation to surgical procedures, with special attention to right ventriculotomy, was investigated. Patients were classified as follows: group Ia (n = 17), transpulmonary-transatrial repair without right ventriculotomy; group Ib (n = 22), transpulmonary-transatrial repair with minimal right ventriculotomy and small transannular patch; and group II (n = 23), transventricular repair with or without transannular patch. For regional wall motion analysis, fractional area change was used for three anterior parts obtained from hemiaxis area analysis of the lateral right ventriculogram. Ejection fractions were used for global right ventricular function. Functional assessment was done both at rest and during isoproterenol infusion, which is a stress test to evaluate cardiac functional reserve. At rest, group Ia showed better right ventricular anterior wall motion as well as global ejection fraction than did group II. Group Ib showed a global ejection fraction comparable to group Ia, with better regional wall motion in the middle anterior part of the right ventricle despite the depressed upper and lower anterior parts of the right ventricle. Group II showed depressed wall motion of the middle anterior part and the resultant impaired global ejection fraction. During isoproterenol infusion, group Ia showed significant increase in fractional area change of all anterior parts and in global ejection fraction. Group Ib showed significant increases in fractional area change at the middle and lower parts and in global ejection fraction comparable with group Ia. Otherwise, group II showed no significant change in fractional area change, or in global ejection fraction, at the upper and middle parts. These results indicated that transpulmonary-transatrial repair for tetralogy of Fallot provided better postoperative global right ventricular function and its reserve, with less impaired regional wall motion, than did the transventricular repair.

Cardiac Catheterization↗
PubMed1990

Myocardial temperature during cardiac operations: influence on right ventricular function.

Maintenance of right heart integrity is frequently neglected during coronary operations. Right ventricular dysfunction sometimes limits the success of the surgical procedure, however. In addition to the use of cardioplegic solutions, myocardial hypothermia during ischemic cardiac arrest seems to be an important factor for guaranteeing right ventricular performance thereafter. This study was designed to measure myocardial temperature in patients with coronary artery disease who have significant stenosis of the right coronary artery in comparison with those who do not have stenosis of the right coronary artery and to evaluate the influence of myocardial temperature on right ventricular hemodynamics after cardiopulmonary bypass. Right ventricular function was assessed by thermodilution technique, which allows measurement of right ventricular ejection fraction, right ventricular end-diastolic volume, and right ventricular end-systolic volume. Right ventricular temperature differed significantly between the two groups, with the lowest value of 15.1 degrees +/- 1.8 degrees C in the group without stenosis of the right coronary artery and a value of 22.2 degrees +/- 2.1 degrees C in the group with stenosis of the right coronary artery. Left ventricular and septal temperatures were without group differences within the investigation period. Right ventricular hemodynamics were impaired only in the group with stenosis of the right coronary artery with a decrease in right ventricular ejection fraction from 44.2% to 34.1% immediately after termination of bypass and an increase in right ventricular end-diastolic volume index (+38%) and right ventricular end-systolic volume index (+70%). Cardiac index decreased only in this group, too (-22.5%). Analysis of covariance revealed a significant correlation only between changes in right ventricular ejection fraction, right ventricular end-diastolic volume, and right ventricular end-systolic volume and the course of right myocardial temperature. It is concluded that right ventricular hypothermia is more difficult to achieve in patients with a diseased right coronary artery. Constant myocardial hypothermia, however, seems to be important in guaranteeing right ventricular function, which easily can be evaluated by the thermodilution technique.

Body Temperature↗
PubMed1985

[Left ventricular function in essential hypertension during isoproterenol infusion].

The left ventricular function of 23 patients with essential hypertension was investigated during infusion of isoproterenol (ISP). These patients consisted of 13 without cardiac hypertrophy (Group NH) and 10 with cardiac hypertrophy (Group HH). Ten normotensive subjects served as normal controls. To assess left ventricular functions, M-mode echocardiograms were recorded at rest and after ISP infusion for 5 minutes (0.005 and 0.01 microgram/kg/min). There were no significant differences in peak negative dD/dt in all groups at rest. But peak negative dD/dt of Group HH significantly decreased after an infusion of 0.005 microgram/kg/min ISP (Group N: 3.43 +/- 0.69, Group NH: 3.15 +/- 0.61, and Group HH: 2.49 +/- 0.48 cm/sec, respectively). The peak negative dD/dt of Group HH was also significantly decreased after a dose of 0.01 microgram/kg/min. Among all patients with hypertension, peak negative dD/dt correlated inversely with left ventricular mass (LVM) after the infusion of ISP (0.005 microgram/kg/min: r = -0.64, p less than 0.001, 0.01 microgram/kg/min: r = -0.68, p less than 0.001). The peak positive dD/dt of Group HH was significantly decreased only when compared with that of Group N at rest (Group N: 3.15 +/- 0.75, Group NH: 3.02 +/- 0.86, and Group HH: 1.92 +/- 0.68 cm/sec, respectively). The difference between the peak positive dD/dt of Group HH and that of Group N was more prominent after the infusion of ISP than at rest. Among all patients with hypertension, the peak positive dD/dt was inversely related to LVM at rest (r = -0.64, p less than 0.002). There was a similar relation between the two indexes after the infusion of ISP. Peak positive dD/dt was related to peak negative dD/dt after a dose of 0.01 microgram/kg/min in Group HH (r = 0.67, p less than 0.05). There was no significant difference in heart rate, change in blood pressure, or total peripheral vascular resistance after the infusion of ISP. It is concluded that diastolic left ventricular dysfunction and latent systolic left ventricular dysfunction are related to increased LVM in Group HH. It seems that after the infusion of ISP severe diastolic left ventricular dysfunction is related to latent systolic left ventricular dysfunction.

Adult↗
PubMed1996

Automatic Border Detection to Assess Right Ventricular Function Following Surgical Treatment of Thromboembolic Pulmonary Hypertension.

Automatic border detection (ABD) has been developed as a potentially useful means for evaluating ventricular function on line in an automatic fashion. Its success with tracking left ventricular function is established, but little is known about its ability to assess right ventricular (RV) function. Accordingly, 20 patients with severe pulmonary hypertension due to chronic thromboembolic disease underwent standard two-dimensional echocardiography and imaging with ABD before and after pulmonary thromboendarterectomy to correct pulmonary hypertension. ABD-derived results were compared to manually planimetered RV areas calculated from the apical four-chamber view. Doppler tricuspid regurgitant velocity fell significantly with surgery from 4.4 +/- 0.6 to 2.9 +/- 0.7 m/sec (P < 0.001). The mean values for RV areas derived by manual planimetry and ABD were similar, as was fractional area shortening, which improved significantly with surgery (manual 0.24 +/- 0.01 preoperative vs 0.31 +/- 0.11 postoperative, P < 0.05; and ABD 0.19 +/- 0.05 preoperative vs 0.32 +/- 0.15 postoperative, P < 0.001). There was, however, very little correlation between the individual values for ABD versus manually derived RV areas and fractional area shortening, with the best correlation being the RV end-diastolic areas after surgery (y = 0.684x + 7.9, r = 0.564, P = 0.01). These results demonstrate that both manually planimetered RV areas and those determined by ABD can adequately follow changes in ventricular function over time. However, variability within each technique may prevent direct comparison of the absolute values of the two techniques. (ECHOCARDIOGRAPHY, Volume 13, March 1996)

Journal Article↗
PubMed1997

Myocardial viability assessed with fluorodeoxyglucose and PET in patients with Q wave myocardial infarction receiving thrombolysis: relationship to coronary anatomy and ventricular function.

In previously thrombolysed patients, we analysed residual myocardial viability using the PET-FDG technique and correlated its presence and extent to the angiographic appearance of the infarct-related vessel and left ventricular function. Thirty-six patients who had undergone intravenous thromboloysis for acute myocardial infarction 4.8 +/- 7.2 months previously were studied. Coronary angiography, left ventriculography, and assessment of myocardial perfusion and metabolism were all performed within 1 week. All patients exhibited perfusion defects consistent with the clinically identified myocardial infarction site. Residual viability, as assessed by the PET-FDG technique, was present in 53% of cases. The infarct-related coronary artery was patent in 19 (53%) patients (TIMI grade 3, 79%); of the remaining 17 with occluded infarct-related arteries, 11 had collaterals to the infarct area. Significant FDG uptake was observed in 63% of patients with a patent infarct-related artery and in 41% of those with an occluded infarct-related artery. The same study protocol was adopted in a control group of 30 patients with myocardial infarction who did not receive thrombolysis. The number of infarct-related patent vessels was significantly lower in these patients (30 vs 53%) (TIMI grade 3, 56%), but the overall percentage of PET viability was again 53%. Qualitative analysis of the regional perfusion pattern showed that the magnitude and severity of the perfusion defect was similar in the two groups, regardless of the presence or absence of FDG uptake. Global left ventricular function was also similar in the two groups. However, regional wall motion was significantly better in the thrombolysed patients with a patent infarct-related artery than in those who had not received thrombolysis and whose culprit vessel was also patent. In conclusion, the results of our study support the notion that early recanalization of the infarct-related artery is critical for preserving left ventricular function. Although the number of patent infarct-related coronary arteries is greater and left ventricular function is better in successfully thrombolysed patients, the regional metabolic pattern does not apparently correlate with the patency of the infarct-related artery. This suggests that, in "chronic' myocardial infarction, residual tissue viability as assessed by fluorodeoxyglucose uptake does not necessarily correlate with coronary recanalization.

Blood Glucose↗
PubMed1997

Effect of high intensity exercise training on central hemodynamic responses to exercise in men with reduced left ventricular function.

OBJECTIVES: The aim of this study was to evaluate the effects of high intensity exercise training on left ventricular function and hemodynamic responses to exercise in patients with reduced ventricular function. BACKGROUND: Results of studies on central hemodynamic adaptations to exercise training in patients with chronic heart failure have been contradictory, and some research has suggested that training causes further myocardial damage in these patients after a myocardial infarction. METHODS: Twenty-five men with left ventricular dysfunction after a myocardial infarction or coronary artery bypass graft surgery were randomized to an exercise training group (mean age +/- SD 56 +/- 5 years, mean ejection fraction [EF] 32 +/- 7%, n = 12) or a control group (mean age 55 +/- 7 years, mean EF 33 +/- 6%, n = 13). Patients in the exercise group performed 2 h of walking daily and four weekly sessions of high intensity monitored stationary cycling (40 min at 70% to 80% peak capacity) at a residential rehabilitation center for a period of 2 months. Ventilatory gas exchange and upright hemodynamic measurements (rest and peak exercise cardiac output; pulmonary artery, wedge and mean arterial pressures; and systemic vascular resistance) were performed before and after the study period. RESULTS: Maximal oxygen uptake (VO2max) increased by 23% after 1 month of training, and by an additional 6% after month 2. The increase in VO2max in the trained group paralleled an increase in maximal cardiac output (12.0 +/- 1.8 liters/min before training vs. 13.7 +/- 2.5 liters/min after training, p < 0.05), but maximal cardiac output did not change in the control group. Neither stroke volume nor hemodynamic pressures at rest or during exercise differed within or between groups. Rest left ventricular mass, volumes and EF determined by magnetic resonance imaging were unchanged in both groups. CONCLUSIONS: High intensity exercise training in patients with reduced left ventricular function results in substantial increases in VO2max by way of an increase in maximal cardiac output combined with a widening of maximal arteriovenous oxygen difference, but not changes in contractility. Training did not worsen hemodynamic status or cause further myocardial damage.

Cardiac Output↗
PubMed1993

[Effect of dynamic cardiomyoplasty on the left ventricular function and hemodynamics in chronic canine models].

This study was undertaken to examine the effect of cardiac assist and left ventricular function after dynamic cardiomyoplasty (DCMP). In the first group (GI) of 10 mongrel dogs DCMP was drived immediately after wrapping both ventricles by latissmus dorsi muscle flap (LDMF). In the second group (GII) of 10 mongrel dogs DCMP was derived over 6 weeks after production of DCMP for achievement of complete adhesion between LDMF and myocardium. In the both groups, aortic pressure, cardiac output, left ventricular systolic pressure, and ejection fraction of the left ventricle were significantly increased by DCMP driving (p < 0.001). But left ventricular systolic pressure was remarkably increased in GII compared with that of GI (21.2 +/- 10.2% versus 14.0 +/- 9.6%, p < 0.001), and end diastolic pressure of the left ventricle was apparently decreased in GII (61.6 +/- 42.3% p < 0.05). Thus, satisfactory results were recognized that cardiac assist for left ventricular function was enhanced after completion of adhesion between myocardium and LDMF. Echocardiography in GII demonstrated that left ventricular systolic dimention was significantly decreased from 33.8 +/- 1.0 mm to 27.6 +/- 1.2 mm (p < 0.001). Thus, left ventricular fractional shortening was significantly increased from 24.0 +/- 2.4% to 38.0 +/- 2.6% (p < 0.001). However, left ventricle end-diastolic dimention was not changed even during DCMP driving. So disturbance in left ventricular function during diastole could not be recognized. In conclusion, especially after adhesion of both muscles of LDMF and myocardium, effect of cardiac assist was remarkably enhanced, and disturbance of diastolic function of the left ventricle could not be observed.

Animals↗
PubMed1987

Acute haemodynamic effects of a specific bradycardic agent in patients with coronary heart disease and impaired left ventricular function.

Alinidine is a bradycardic agent, which appears to be of potential value in the therapy of coronary heart disease. It might be useful in patients with impaired left ventricular function, where use of other bradycardic agents such as beta-blockers is limited due to their negative inotropy. To assess if alinidine has the potential to worsen haemodynamics in patients with strongly reduced left ventricular function we have examined acute haemodynamic changes after alinidine (0.5 mg kg-1 i.v.) both in a group of patients with mildly and in a group with strongly reduced left ventricular function. A significant reduction of resting heart rate and cardiac index was observed in both groups. All other haemodynamic parameters, especially left ventricular filling pressures (LVEDP, PC) and enddiastolic volume index did not show any significant change; dp/dtmax was not significantly influenced by alkinidine, when the influence of heart rate lowering was eliminated by pacing. We conclude that administration of alinidine in the dosage used does not lead to a significant deterioration even in patients with strongly impaired left ventricular function.

Anti-Arrhythmia Agents↗
PubMed2003

Inter-hospital transport for primary angioplasty does not compromise left ventricular function: six-month echocardiographic follow-up of the PRAGUE 1 Study.

The main aim of the present study was to investigate whether long distance interhospital transport for primary angioplasty (delayed mechanical reperfusion) influences the resulting left ventricular function after myocardial infarction as compared with thrombolysis at the nearest hospital (immediate pharmacological reperfusion). Primary coronary angioplasty is more effective than thrombolysis in restoring coronary flow in patients with acute myocardial infarction. It is not known whether a delay in reperfusion due to transport to an angioplasty centre compromises left ventricular function, and whether combination therapy (ie, thrombolysis during transport to an angioplasty centre) would help preserve ejection fraction. The "PRAGUE-1" Study randomised 300 patients with myocardial infarction admitted to community hospitals without a cath-lab into 3 groups: group A (thrombolysis, no transport, n = 99), group B (thrombolysis during transport to an angioplasty centre, n = 100), and group C (transport for primary angioplasty, n = 101). Transport distances were below 75 kilometres, and mean transport time was 38 minutes. This paper presents for the first time the echocardiographic data from the early (discharge, day 30) and mid-term (6 months) follow-up. Only patients who survived until discharge (A: 85, B: 88, C: 94) could be analysed. Ejection fraction improved between discharge and 6 months (P < 0.01) in all three groups: from 47% to 51% in group A, from 47% to 52% in group B, and from 48% to 52% in group C. The differences between the groups were not significant. The same differences were found for the wall motion score index. Left ventricular end-diastolic diameter did not differ between the groups/examinations. Greater improvement was documented in the period between hospital discharge and day 30, compared to the period between day 30 and 6 months. The time delay associated with an inter-hospital transport strategy for primary angioplasty did not compromise left ventricular function. The strategy of thrombolysis during transport did not further improve left ventricular function compared to transport for primary angioplasty alone.

Aged↗
PubMed1978

Left ventricular function in exercise-induced hypertrophy in dogs.

Indexes of left ventricular function and diastolic compliance were studied in 10 awake exercise-trained greyhounds with left ventricular hypertrophy. Mean left ventricular to body weight ratio and mean myocardial cell diameter were significantly greater than in normal dogs (8.73 +/- 2.7 [standard error of the mean] versus 4.63 +/- 0.24 g/kg, P less than 0.01; and 18.3 +/- 0.67 versus 12.5 +/- 0.71 mu, P less than 0.01, respectively). In awake resting animals, 7 to 50 days after implantation of a high fidelity micromanometer and sonomicrometer crystals, left ventricular contractility indexes were similar to those measured previously in normal dogs (maximal derivative of left ventricular pressure [dP/dt] 3,800 +/- 250 versus 3,810 +/- 330 mm Hg/sec, difference not significant; and mean rate of circumferential fiber shortening 1.54 +/- 0.12 versus 1.43 +/- 0.12 sec-1, difference not significant). During volume loading sufficient to produce a left ventricular end-diastolic pressure of 20 mm Hg, changes in contractility indexes were similar to those in normal dogs; however, heart rate increased significantly (74 percent, P less than 0.005) in the trained greyhounds but not in normal dogs. Left ventricular diastolic stiffness did not differ from normal (51.6 +/- 3.0 versus 45.9 +/- 5.9 mm Hg/cm, P less than 0.01). These findings suggest that left ventricular function in exercise-induced left ventricular hypertrophy is substantially normal.

Animals↗
PubMed2004

Regional right and left ventricular function after the Senning operation: an ultrasonic study of strain rate and strain.

BACKGROUND: Systemic right ventricular dysfunction is a major concern in the follow-up of patients who underwent an atrial redirection procedure for transposition (concordant atrio-ventricular and discordant ventriculo-arterial connections). No good non-invasive method is currently available for quantifying right ventricular function. AIMS: We have used ultrasonically based imaging of strain rate and strain to quantify regional deformation in the right ventricle after the Senning operation, comparing properties of regional deformation of the right ventricle with right ventricular ejection fraction as measured using magnetic resonance imaging. METHODS: In 20 asymptomatic patients who had undergone the Senning procedure, we measured peak systolic strain rate and systolic strain values in the right ventricular free wall, the septum and the left ventricular lateral wall using colour Doppler myocardial imaging, comparing the data with findings obtained in 30 healthy subjects. Global right ventricular ejection fraction was assessed using magnetic resonance imaging. RESULTS: Properties of deformation of the right ventricular free wall were reduced and homogeneous after the Senning procedure compared to normals, with significantly lower values for peak systolic strain rate and systolic strain (-1.1 +/- 0.4 vs. -2.5 +/- 0.9 s(-1); p < 0.05 and -16 +/- 7% vs. -38 +/- 13%; p < 0.05, respectively). There was a significant correlation between regional longitudinal right ventricular systolic strain values and right ventricular ejection fraction (r = -0.87, p < 0.001). In the septum, peak systolic strain rate was again reduced and homogeneous (-1.2 +/- 0.4 vs. -1.8 +/- 0.5 s(-1); p < 0.05 vs. normals). Also in the left ventricle, the lateral wall peak systolic strain rate and systolic strain values were reduced (-1.5 +/- 0.5 vs. -2.1 +/- 0.9 s(-1); p < 0.05 and -20 +/- 6% vs.-25 +/- 9%; p < 0.05, vs. normals, respectively). CONCLUSIONS: Properties of regional longitudinal deformation of the systemic right ventricle are reduced after the Senning procedure compared to normal controls, and correlate well with global right ventricular performance. These findings suggest that ultrasonic strain rate and strain imaging could be used in the non-invasive follow-up of ventricular function in these patients.

Adolescent↗
PubMed1968

Left ventricular function in patients with chronic obstructive pulmonary disease.

Left ventricular function was assessed in six patients with essentially normal cardiopulmonary function, in five patients with primary myocardial disease, and in 16 patients with chronic obstructive pulmonary disease by determining the response of the ventricle to an increased resistance to ejection. Studies were performed at the time of cardiac catheterization and increased resistance to left ventricular ejection was produced by the intravenous infusion of methoxamine. In the control patients, methoxamine produced an increase in stroke volume index (SVI), in stroke work index (SWI), and stroke power index (SPI), whereas left ventricular end-diastolic pressure (LVEDP) increased only moderately. In contrast SVI, SWI, and SPI fell, whereas LVEDP increased inordinately in the patients with myocardiopathy. The patients with chronic obstructive pulmonary disease responded to the infusion with an increase in SVI, SWI, SPI, and LVEDP comparable to the control patients. Furthermore, in this latter group of patients, a quantitatively similar response was observed in those with essentially normal resting hemodynamics, in those with resting pulmonary hypertension, and in those whose disease had progressed to the stage of right ventricular failure. This study provides no evidence that chronic obstructive pulmonary disease results in chronic impairment of left ventricular function, but on the contrary, has demonstrated that the left ventricle responds normally to an increased pressure load in these patients.

Adult↗
PubMed1990

[Evaluation of systolic and diastolic left ventricular function in acute myocardial infarction by aortic echogram].

A noninvasive method for the measurement of the cardiac output and diastolic ventricular function was evaluated by aortic echogram in a group of patients with acute myocardial infarction (AMI). The following parameters were employed: average of initial and late aortic cusp separation (ACS), left ventricular ejection time (EP) and amplitude of aortic posterior wall during ejection (AA). The following formula was used: cardiac output (CO) = (ACS x EP) x 100 + AA x HR. Diastolic ventricular function was evaluated by the left auricle emptying index (LAEI) described by Strunk et al. This last relationship X/OA where X is the movement of the aortic posterior wall (AP) at the first third of passive diastole, and OA is the total aortic movement during the passive diastole. All patients were followed by cardiac output measurements by thermodilution and pulmonary capillary pressure (PCP). Twenty measurements were made in fourteen subjects; for CO a good lineal correlation was found (r = 0.81). As for diastolic ventricular function, LAEI reached a value of 0.49 (+/- 0.23); normal value was 0.82 (p less than 0.01); it was significantly diminished showing the stiffness of the chamber. The utilization of aortic echogram and the analysis of movement of APW result in a non invasive reliable procedure that can be repeated to evaluate the hemodynamic situation in AMI.

Aged↗
PubMed1991

[Prognostic significance of radionuclide-assessed right ventricular function in dilated cardiomyopathy].

To assess the prognostic significance of right ventricular function in dilated cardiomyopathy (DCM), we studied consecutive 57 DCM patients. There were 41 men and 16 women, whose mean age was 48 ys. (range 3-68 ys.). The mean LVEF in all patients was 29 +/- 11%, and the mean interval from the onset of symptom of cardiac failure (CHF history) was 4 ys. (range 0-33 ys.). With follow-up of 3.8 ys., five patients had died until the first year, and 14 had died until the third year. By using multivariate regression analysis, there were no prognostic significance in clinical parameters such as age, CHF history, sex, atrial fibrillation, except for NYHA class, and medication at the third year. In survival curves according to Kaplan-Meier method, RVEF and mean PA had predictive value (p less than 0.05), while LVEF did not. The patients with RVEF less than 45% had poor survival rate compared to those with RVEF greater than or equal to 45%. The patients with RVEF less than 45% showed lower LVEF and LVESVI. RVEF may offer prognostic predictive value through the effect of not only mean PA but also left ventricular parameter. In conclusion, radionuclide assessment of right ventricular function should be valuable for the prognostic evaluation of DCM patients.

Adolescent↗
PubMed1989

The effect of acute hypoxaemia on ventricular function during beta-adrenergic and cholinergic blockade in the fetal sheep.

The effect of acute hypoxaemia on right and left ventricular function was investigated in 8 fetal sheep (137-140 days gestation). Fetuses were instrumented with electromagnetic flow sensors on the ascending aorta and the main pulmonary artery. After 8 days recovery, hypoxaemia was achieved by reducing the maternal ewe's inspired O2 concentration to 13.1 +/- 1.5%. Control and hypoxaemic arterial blood values were pH 7.37 +/- 0.04 (SD) and 7.35 +/- 0.06, PCO2 48.0 +/- 2.8 and 47.6 +/- 5.1 mmHg, PO2 19.9 +/- 2.2 and 11.4 +/- 1.5 mmHg, haematocrit 37.5 +/- 1.2 and 39.5 +/- 2.2, respectively. Arterial pressure increased insignificantly with acute hypoxaemia (50.2 +/- 3.9 to 53.6 +/- 8.1 mmHg). Left and right ventricular performance was assessed by generating biventricular function curves relating stroke volume to mean atrial pressure. All function curves were composed of steep ascending and plateau limbs that intersected at a breakpoint. Comparing control and hypoxaemia function curves, the left ventricular stroke volume breakpoints were 0.79 +/- 0.20 and 0.78 +/- 0.21 ml/kg, respectively, while the right ventricular stroke volume breakpoints were 0.99 +/- 0.11 and 0.88 +/- 0.21 ml/kg (n.s.). In 4 fetuses, acute hypoxaemia was associated with significant increases in arterial blood pressure (P less than 0.05). In these fetuses, the right ventricular function curve was shifted significantly downward compared to the control right ventricular curve. When nitroprusside was given to these hypertensive fetuses to return blood pressure to control levels, the right ventricular function curve returned to baseline. We conclude that even under conditions of extreme hypoxaemia, ventricular function is well preserved in the normotensive fetal sheep. However, when increases in arterial pressure also accompany hypoxaemia, detectable changes in right ventricular function can be accounted for by changes in arterial pressure.

Animals↗
PubMedDate not supplied

Effect of phenylephrine bolus administration on left ventricular function during postural hypotension in anesthetized patients.

STUDY OBJECTIVE: To investigate the effect of intravenous (IV) phenylephrine (PHE) bolus administration on left ventricular function in patients who developed postural hypotension during isoflurane anesthesia in the head-up tilt (reverse Trendelenburg) position. DESIGN: Prospective "before-after" trial. SETTING: Operation theater of a university medical center. PATIENTS: 15 ASA physical status I and II patients without cardiovascular disorders. INTERVENTIONS: The anesthetized patients were tilted from a supine horizontal to a 30-degree reverse-Trendelenburg position. Once a steady state was achieved, PHE 3 micrograms/kg was administered as an IV bolus dose. MEASUREMENTS AND MAIN RESULTS: Transesophageal echocardiography was used to assess left ventricular function. We measured blood pressure (BP); heart rate; left ventricular end-systolic and end-diastolic area, diameter, and wall thickness; and ejection time at baseline and after tilt, immediately before and for a period of 3 minutes after PHE injection. We calculated fractional area change (FAC), mean velocity of circumferential fiber shortening (mVcf), and end-systolic wall stress. Head-up tilt caused a reduction of mean arterial pressure [from 68 to 54 mmHg (mean)], end-systolic and end-diastolic left ventricular area (from 9.7 to 6.5 cm2 and from 19.2 to 13.1 cm2, respectively) and end-systolic wall stress (from 56 to 33 10(3).dyne/cm2). FAC and mVcf remained unaltered. PHE administration restored baseline values or overcompensated the changes caused by tilt. FAC slightly decreased in response to PHE (from 0.51 to 0.43), end-systolic wall stress increased to 83 10(3).dyne/cm2, and mVcf remained unchanged. CONCLUSION: PHE bolus administration effectively restored BP and cardiac filling, which were reduced after head-up tilt, without causing a relevant impairment of left ventricular function or an increase in end-systolic wall stress above the upper normal limit.

Adult↗
PubMed1992

Ventricular function by radionuclide ventriculography in malignant hypertension.

Malignant hypertension is a unique and natural model for the study of abnormalities of left ventricular function due to arterial hypertension, because the development and regression of these abnormalities can be observed in a short period. Studies of ventricular function by radionuclide ventriculography, either before or after therapy, have not been previously reported in malignant hypertensive patients. We used this methodology to study left ventricular function in 17 malignant/accelerated hypertensive patients at the time of admission to the hospital and 3, 6, and 9 months after discharge. Seventy percent of patients (12 of 17) had symptoms of congestive heart failure at admission. We compared these data with those obtained in 12 normotensive subjects and 13 mild-to-moderate untreated hypertensive patients. Blood pressure of malignant hypertensive patients was 213 +/- 26/140 +/- 17 mm Hg at admission and 165 +/- 23/101 +/- 15 after 9 months of therapy. Radionuclide ventriculography at admission showed that peak filling rates of malignant hypertensive patients (2.13 +/- 0.21 end-diastolic volume [counts] [EDV]/sec) were significantly lower than those in normotensive subjects (2.40 +/- 0.41) and in mild-to-moderate hypertensive patients (2.46 +/- 0.21). In contrast, peak ejection rates were significantly higher in malignant hypertensive patients (3.44 +/- 0.38 EDV/sec) than in the two control groups (3.01 +/- 0.32 and 3.10 +/- 0.43, respectively). Ejection fractions were similar in the three groups of patients. After 9 months of therapy, peak filling rates of malignant hypertensive patients increased to 2.38 +/- 0.35 EDV/sec, whereas peak ejection rates decreased to 2.89 +/- 0.43 EDV/sec, both not significantly different from data in controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2000

Head to head comparison of dobutamine-transoesophageal echocardiography and dobutamine-magnetic resonance imaging for the prediction of left ventricular functional recovery in patients with chronic coronary artery disease.

AIMS: A substantial number of patients with dysfunctional but potentially viable myocardium cannot be accurately evaluated by transthoracic echocardiography due to a poor acoustic window. This study compares the diagnostic value of alternative functional imaging techniques, such as dobutamine-transoesophageal echocardiography (dobutamine-TEE) and dobutamine magnetic resonance imaging (dobutamine-MRI) for the detection of viable myocardium and the prediction of left ventricular functional recovery in patients with chronic coronary artery disease following successful revascularization procedures. METHODS AND RESULTS: Rest and low-dose (5, 10 microg dobutamine x min(-1) x kg(-1)) multiplane dobutamine-TEE and ultrafast cine-MRI studies were performed in 103 patients. Contractile recovery of an infarct region was predicted if a dobutamine contraction reserve could be assessed visually by TEE or MRI in > or =50% of infarct-related a- or dyskinetic segments. Revascularization of the infarct-related vessel was successful in 88 patients, and 4.9 +/- 0.7 months later 52 patients still had an angiographically controlled open target vessel. These patients underwent another rest MRI study to assess left ventricular functional recovery. A dobutamine contraction reserve was observed in 27/52 (52%) patients by TEE and in 26/52 (50%) patients by MRI. Functional improvement of the infarct region was diagnosed in 28/52 (54%) patients. The positive and negative predictive accuracy of dobutamine-TEE and dobutamine-MRI for the prediction of left ventricular functional recovery was not significantly different (85% vs 92%, ns and 80% vs 85%, ns). Diagnosis of a predominantly viable infarct region by TEE and MRI predicted a significant increase in left ventricular ejection fraction (TEE: 12 +/- 8% vs 2 +/- 7% P<0.001, MRI: 13 +/- 7% vs 2 +/- 7%, P<0.001) compared to infarct regions graded as scar. CONCLUSION: A qualitative visual analysis of TEE and MRI viability studies is highly accurate for the prediction of left ventricular functional recovery in patients with dysfunctional myocardium and proved to be a clinically valuable alternative if transthoracic dobutamine-echocardiography is unsuitable. To date, TEE is cardiologists' preferred choice for the assessment of myocardial viability but MRI may become significantly more attractive with increasing local availability and experience.

Aged↗