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PubMed1992

[Assessment with magnetic resonance tomography of anatomy and ventricular function after Mustard correction of transposition of the great arteries].

In order to evaluate postoperative sequelae and ventricular function after Mustard-operation in patients with transposition of the great arteries (TGA), 30 patients were assessed by magnetic resonance imaging in EKG-triggered spin-echo (SE) and gradient-echo (GE) technique. Twenty-three patients, aged 4.7 to 15.8 years, had transposition of the great arteries with intact ventricular septum with or without left-ventricular outflow tract obstruction (TGA+IVS +/- SPS). Seven patients aged 9.5 to 21.7 years had transposition of the great arteries with ventricular septal defect (TGA+VSD). Five patients showed a residual baffle leak, one had a pulmonary venous obstruction, five an obstruction at the caval veins, 13 a left-ventricular outflow tract obstruction, and 14 a tricuspid regurgitation. Right-ventricular enddiastolic volume in patients with TGA+VSD (77.0 +/- 25.5 ml/m2) was significantly higher than in patients with TGA+IVS +/- SPS (61.2 +/- 12.0 ml/m2). In TGA+VSD right-ventricular ejection fraction (47.6 +/- 13.0%) was significantly lower than in patients with TGA+IVS +/- SPS (56.7 +/- 10.7%). The ratio of muscle masses of right to left ventricle was 1.8:1 in patients with TGA+IVS +/- SPS and 2.5:1 in patients with TGA+VSD. In conclusion, after Mustard-operation in patients with transposition of the great arteries (TGA) magnetic resonance imaging provides a comprehensive and noninvasive assessment of postoperative sequelae, residuae, and ventricular function and will, therefore, become the method of choice for postoperative evaluation.

Child, Preschool↗
PubMed2006

[Assessment of global left ventricular function with multi-slice spiral computed tomography].

OBJECTIVE: To investigate the value of multi-slice spiral computed tomography (MSCT) in the determination of global left ventricular function. METHODS: Twenty-nine patients with confirmed or suspected coronary heart diseases were imaged with a contrast-enhanced retrospective electrocardiogram (ECG) -gated technique on a 64-slice spiral CT scanner. The data sets were reconstructed at both end-diastolic and end-systolic phases in order to measure left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular stroke volume (LVSV), and left ventricular ejection fraction (LVEF). The results were compared with corresponding values obtained from conventional left ventriculography (LVG). RESULTS: LVEDV, LVESV, LVSV, and LVEF obtained with 64-slice spiral CT were significantly correlated with the LVG data (r = 0. 887-0.956, P < 0.001). According to the Bland-Altman approach, the mean differences for LVEDV, LVESV, LVSV, and LVEF were -2.3 ml, 4.1 ml, -6.4 ml, and - 3.5%, respectively. The limits of agreement for LVEDV, LVESV, LVSV, and LVEF were -27.2-22.4 ml, -10.2-18.4 ml, -26.4-13.6 ml, and -9.8%-3.0%, respectively. CONCLUSION: MSCT has clinically acceptable agreement with LVG for the quantification of global left ventricular function.

Adult↗
PubMed1999

[Changes in left ventricular function during chemotherapy with doxorubicin].

The authors investigated by echocardiography changes of left ventricular function in 79 patients with non-Hodgkin lymphoma or Hodgkin's disease who were treated by chemotherapy containing doxorubicin. In 22% patients they diagnosed during treatment a significant gradual decline of the left ventricular ejection fraction (change > 10% or a drop of EF below 50%) after a cumulative dose of 185 +/- 52 mg/m2 doxorubicin (median 200 mg/m2). Changes of the ejection fraction were at the expense of an increasing endsystolic left ventricular volume. These changes correlated closely with the increase of endsystolic stress of the left ventricular wall (r = -0.87). After administration of a cumulative doxorubicin dose of 100 mg/m2 a significant deterioration of indicators of diastolic filling of the left ventricle occurred--of the isovolumic relaxation period (IRP) and deceleration time (DT). The contribution of these early changes of diastolic function of the left ventricle for assessment of the risk of development of systolic dysfunction is not unequivocal. Prolongation of IRP > 12% as compared with the baseline value and at the same time above 95 ms had a 50% sensitivity, 50% specificity, a 26% positive prediction value a 74% negative prediction value and 50% diagnostic accuracy, change of DT > 13%, and at the same time prolongation above 200 ms had a 47% sensitivity 55% specificity, a 22% positive prediction value, a 78% negative prediction value and a 53% diagnostic accuracy. The authors found a significant relationship between the assessed changes of left ventricular function and clinical and haemodynamic indicators. Only the patients' age correlated significantly with IRP and DT values. Changes of the left ventricular ejection fraction were not associated with clinical signs of cardiac failure, they did not call for cardiological intervention and did not affect the course of chemotherapy. Contrary to some statements in the literature, the authors did not consider the described functional changes as sufficient to justify interference with chemotherapy. On the other hand, their importance for the development of late sequelae of chemotherapy with anthracyclines in adult patients must be based on long-term prospective follow-up.

Adolescent↗
PubMedDate not supplied

Left ventricular function of heart allografts during acute rejection: an echocardiographic assessment.

Left ventricular function was evaluated in nine patients during biopsy proven acute rejection of heart allografts using computer-assisted analysis of echocardiograms. The results were compared with data obtained during their non-rejection state and with data obtained from 10 normal subjects. Left ventricular dimensions and parameters of diastolic and systolic function of non-rejecting hearts were similar to those of normals. Acute rejection was associated with increased left ventricular mural thickness and mass, and abnormal diastolic function characterized by a prolongation of the rapid filling period from 155 msec +/- 14 msec to 183 msec +/- 16 msec (p less than 0.05, mean +/- SE), and decreased normalized peak rates of left ventricular lengthening (from 5.3 sec-1 +/- 0.8 sec-1 to 3.9 sec-1 +/- 0.4 sec-1, less than 0.05) and posterior wall thinning (from 7.4 sec-1 +/- 1.0 sec-1 to 3.8 sec-1 +/- 0.6 sec-1, p less than 0.05). Parameters of systolic function as defined by fractional shortening, peak normalized rates of left ventricular shortening and posterior wall thinning were not altered by acute rejection. We conclude that the left ventricular function of non-rejecting hearts is similar to that of normals; however, acute rejection is associated with abnormal left ventricular diastolic dynamics without adverse effect on systolic function.

Adult↗
PubMed1975

Assessment of left ventricular function in secundum atrial septal defect: evaluation by determination of volume, pressure, and external systolic time indices.

Left ventricular function and volume data from 17 control subjects and 27 young patients with secundum atrial septal defect (ASD) without overt left or right ventricular failure were compared. ASD patients were subdivided in low shunt (Qp/Qs less than 2.0) and high shunt (Qp/Qs larger than or equal to 2.0) groups. Mean left ventricular (LV) stroke volume was significantly less in ASD patients (46 +/- 16 ml/m2 in the low shunt and 44 +/- 9 ml/m2 in high shunt group) compared with control patients (51 +/- 13 ml/m2, P less than 0.01 and P less than 0.02, respectively). There was no significant difference in mean left ventricular end-diastolic volume (LVEDV) between any group of patients (control subjects 67 +/- 17 ml/m2; low shunt ASD 66 +/- 17 Ml/m2, and high shunt ASD 62 +/- 12 ml/m2). High shunt ASD had a significantly lower cardiac index compared with control patients (5.0 liters/min/m2 vs. 5.9 liters/min/m2, P less than 0.02). Both low shunt and high shunt ASD showed significantly lower stroke work indices than control subjects (42 +/- 13 GmM/m2 and 37 +/- 8 GmM/m2 compared with 51 +/- 14 GmM/M2 , P less than 0.05 and P less than 0.001, respectively) but only the high shunt group had a significantly lower peak systolic pressure (94 +/- 12 mm Hg vs. 109 +/- 11 mm Hg for control patients, P less than 0.01). There was no significant difference between the control and ASD groups in LV end-diastolic, mean right atrial, right ventricular end-diastolic, and pulmonary pressures. External systolic time intervals were compared in 5 control and 12 ASD patients. There was no significant difference between the two groups of patients in absolute values or indices for pre-ejection period, ejection time, or electromechanical systole. However, the ratio of the pre-ejection period index to left ventricular ejection time index (PEPI/LVETI) was significantly higher in ASD patients (P less than 0.05). In young subjects with large shunt ASD, certain indicators of left ventricular function are depressed. Evaluation of PEPI/LVETI may allow noninvasive determination of LV function.

Adolescent↗
PubMed2004

Effects of antiarrhythmic agents on left ventricular function during exercise in patients with chronic left ventricular dysfunction.

This study was designed to determine the effects of antiarrhythmic agents on global left ventricular (LV) function during exercise in patients with chronic LV dysfunction. Thirty-five patients with LV dysfunction [LV ejection fraction (LVEF) < 45%] and ventricular arrhythmias were studied. They were randomly classified into 3 groups: patients who received a single oral dose of 6 mg/kg disopyramide phosphate (n = 12), those who received a single oral dose of 4 mg/kg mexiletine hydrochloride (n = 12), and those who received a single oral dose of 4 mg/kg pilsicainide hydrochloride (n = 11). First, all patients were subjected to baseline rest and peak exercise, equilibrium-gated cardiac-pool scintigraphy with 99mTc-human serous albumin of 740 MBq (baseline data). Second, on a separate day, they were given drugs once, and were subsequently subjected to rest and peak exercise equilibrium-gated cardiac-pool scintigraphy. Exercise LVEF and peak ejection rate (PER) after administration were significantly lower in the disopyramide and pilsicainide groups than in the mexiletine group (p < 0.05, respectively). The changes in LVEF and PER from rest to peak exercise after administration were significantly less than the baseline changes in those in the disopyramide and pilsicainide groups (p < 0.05, respectively). However, no significant changes in functional parameters were recognized in the mexiletine group. Due care should be taken when disopyramide and pilsicainide are administered to patients with chronic LV dysfunction since they reduce systolic LV function during exercise.

Aged↗
PubMed1991

Comparative effects of APSAC and rt-PA on infarct size and left ventricular function in acute myocardial infarction. A multicenter randomized study.

BACKGROUND: Recombinant tissue-type plasminogen activator (rt-PA or alteplase) and anisoylated plasminogen streptokinase activator complex (APSAC or anistreplase) have been demonstrated to limit infarct size significantly and to preserve left ventricular function when injected soon after acute myocardial infarction. However, as yet, the efficacy and safety of these two thrombolytic agents have not been directly compared in one trial; this was the aim of this study. METHODS AND RESULTS: One hundred eighty-three patients suffering from a first acute myocardial infarction were randomly allocated to either APSAC (30 units over 5 minutes) or single-chain rt-PA (100 mg over a 3-hour period) within 4 hours of the onset of symptoms. Global and regional left ventricular function were assessed from contrast angiography an average of 5.3 +/- 2.3 days after initial therapy. Radionuclide angiography and thallium-201 single-photon emission computerized tomography were performed before hospital discharge. Infarct size was assessed by single-photon emission computerized tomography and expressed in percentage of the total myocardial volume. Ninety patients received APSAC and 93 received rt-PA within a mean period of 172 +/- 52 minutes after the onset of symptoms. The two groups were similar in age, location of the acute myocardial infarction, Killip class, and time of randomization. The patency rate of the infarct-related artery was 72% in the APSAC group and 76% in the rt-PA group (NS). Initial and predischarge left ventricular ejection fraction as well as infarct size were similar in both therapeutic groups (0.50 +/- 0.14 versus 0.52 +/- 0.12 for initial and 0.48 +/- 0.10 versus 0.47 +/- 0.10 for predischarge ejection fraction, 11 +/- 7% versus 9 +/- 7% for infarct size, respectively, for APSAC- and rt-PA-treated patients). Bleeding complications requiring blood transfusion occurred in one APSAC patient and in two rt-PA patients. One patient in the rt-PA group died of a massive intracranial hemorrhage. At the end of the 3-week follow-up period, five APSAC patients (5.5%) and seven rt-PA patients (7.5%) had died. CONCLUSIONS: The early infusion of APSAC or rt-PA in acute myocardial infarction produced a similar patency rate, limitation of infarct size, and preservation of left ventricular systolic function with an equivalent rate of bleeding complications.

Anistreplase↗
PubMed1991

[Right ventricular function before and 6 months after aortocoronary bypass. A radioisotope angiographic study].

The aim of the present paper is the study of the changes induced on right ventricular function after myocardial revascularization with aortocoronary bypass graft. Two-three days before and 6 months after operation gated radionuclide ventriculography has been performed in 25 patients with previous myocardial infarction (MI), anterior in 16 patients and inferior in 9. At postoperative examination, right ventricular ejection fraction (EF) was slightly but significantly reduced (p less than 0.01), while peak ejection and filling rates were unchanged. Symmetric parameters of left ventricular function did not show changes at post-operative control, except a clear-cut rise of left ventricular peak filling rate (p less than 0.05). Before operation, in patients with previous anterior MI, left ventricular EF was slightly less and right ventricular EF slightly more than in patients with previous inferior MI; after operation right ventricular EF significantly decreased (p less than 0.01) only in patients with previous anterior MI. No correlation has been demonstrated in pre- postoperative changes of the observed parameters, neither between the two groups of previous MI nor between right and left ventricular cavity. Six months after myocardial revascularization, left ventricular performance, as examined with radionuclide angiography, was practically unchanged except for improvement of diastolic function, while right ventricular performance was moderately impaired, more in patients with previous anterior MI than in those with previous inferior MI.

Adult↗
PubMed1997

Evaluation of the effects of mivacurium chloride on hemodynamics and left ventricular function in patients with coronary artery disease undergoing abdominal aortic surgery.

OBJECTIVE: To determine the effects of two doses of mivacurium chloride on hemodynamics and left ventricular function in patients with documented coronary artery disease undergoing aortic surgery. DESIGN: A prospective study with the dose of mivacurium determined by randomization. SETTING: Induction area at a university hospital. PARTICIPANTS: Twenty consecutive patients undergoing aortic surgery with clinically and/or angiographically documented coronary artery disease. INTERVENTIONS: Intravenous administration of mivacurium chloride. MEASUREMENTS AND MAIN RESULTS: Induction of anesthesia was performed with midazolam and fentanyl. Two different doses of mivacurium chloride, 0.15 mg/kg (n = 10) and 0.2 mg/kg (n = 10; 2 and 2.5 ED95; respectively), were administered as a single bolus injection over a 60-second period in the absence of any surgical stimulation. In addition to standard hemodynamic monitoring, pulmonary artery catheterization and transesophageal echocardiography were used. The occurrence of myocardial ischemia was monitored using both a computerized three-lead ST-segment analysis system and the echocardiographic assessment of regional wall motion. No change in heart rate, mean arterial pressure, pulmonary capillary wedge pressure, cardiac output, and global left ventricular function was noted after administration of mivacurium with the two doses studied. No ST-segment change or new segmental wall motion abnormality was noted in either group. CONCLUSION: Mivacurium chloride, when injected over a 60-second period, preserves global and regional myocardial function in patients with documented coronary artery disease undergoing noncardiac surgery.

Adult↗
PubMed1984

Right and left ventricular function at rest and with exercise after the Mustard operation for transposition of the great arteries.

Right and left ventricular function was assessed in 25 children (mean age at study 12.2 years and at operation 2.6 years) after a Mustard repair for transposition of the great arteries. Gated first pass and gated equilibrium radionuclide ventriculography was performed on all patients at rest and during supine bicycle exercise. The mean right ventricular ejection fraction did not increase with exercise by either technique. Individual results for right ventricular ejection fraction showed that with the gated equilibrium technique 71% had an abnormal exercise response (normal response being an increase in ejection fraction greater than 5%) and with the gated first pass technique 61% had abnormal results. Although the mean left ventricular ejection fraction increased significantly with exercise, 35% of patients had an abnormal exercise response with the equilibrium technique and 41% with the first pass technique. There was no evidence of a predictive relation between ventricular function and any clinical or haemodynamic variable examined. Covert right and left ventricular dysfunction can frequently be detected by exercise radionuclide ventriculography in long term survivors of repair for transposition of the great arteries. The prognostic consequences of these findings are unclear at present.

Adolescent↗
PubMedDate not supplied

Right ventricular function after coronary surgery with or without bypass.

BACKGROUND AND OBJECTIVE: Myocardial protection during aortic clamp period may sometimes be inadequate, especially for the right. The aim of this study was to compare right ventricle function after cardiac surgery with or without bypass. METHODS: Patients undergoing multivessel coronary surgery with proximal severe right coronary lesion were included in a prospective observational cohort study including 29 patients undergoing coronary surgery with or without bypass. All patients were monitored with a pulmonary artery catheter with continuous right ventricular function. Right ventricular ejection fraction was measured at the arrival in ICU, 1, 3, 6, and 18 hours later. RESULTS: The number of grafts that was higher in the bypass group (4.0 +/- 1.3) than in the off-pump group (2.6 +/- 0.6, p = 0.001). In the on-pump group, the right ventricular ejection fraction significantly decreased from 32.9 +/- 2.8 at arrival in ICU to 26.1 +/- 2.4, 6 hours later whereas in the off-pump group, it did not significantly change (32.4 +/- 1.8 to 31.9 +/- 2.3). Meanwhile, at the same time intervals, CVP was significantly lower in the off-pump group. CONCLUSIONS: In patients with severe right coronary stenosis, off-pump cardiac surgery seemed to provide better right ventricular protection.

Adult↗
PubMed1990

Simultaneous measurement of myocardial perfusion and ventricular function during exercise from a single injection of technetium-99m sestamibi in coronary artery disease.

New radiopharmaceuticals permit simultaneous assessment of myocardial perfusion and left ventricular function using a single tracer injection. The purpose of this study was to quantitate the relation between myocardial perfusion and function at rest and during exercise in patients with documented coronary artery disease (CAD). A rest first-pass radionuclide angiocardiogram (RNA) was recorded in 51 patients with CAD during injection of 10 mCi of technetium-99m (Tc-99m) sestamibi, and tomographic perfusion images were obtained 60 minutes later. A treadmill test was then performed, and on attainment of an exercise end point a second first-pass RNA was recorded with 30 mCi of Tc-99m sestamibi. Tomographic images reflecting myocardial perfusion during exercise were obtained 1 hour later. Tomographic perfusion defect size, quantified using modifications of the Cedars-Sinai program, correlated directly with end-systolic volume and inversely with ejection fraction at rest and during exercise. However, perfusion defect size often varied widely in patients with similar left ventricular function. This independence between measurements of perfusion and function suggests that simultaneous assessment of the 2 physiologic variables could improve the diagnostic and prognostic information of radionuclide tests.

Coronary Disease↗
PubMed2005

Intraatrial repair of transposition of the great arteries: use of MR imaging after exercise to evaluate regional systemic right ventricular function.

PURPOSE: To prospectively assess regional systemic right ventricular (RV) function at rest and in response to exercise by using magnetic resonance (MR) imaging in patients who have undergone surgical correction at the atrial level for transposition of the great arteries (TGA). MATERIALS AND METHODS: Informed consent was obtained, and the medical review board approved this study. In 25 adult patients (mean age, 25.8 years +/- 4.7 [standard deviation]; 13 men) who had undergone correction for TGA (23.4 years +/- 4.9 after surgery) and 11 healthy volunteers (mean age, 27.4 years +/- 2.7; six men), systemic ventricular function was assessed with MR imaging (turbo field echo-planar imaging) at rest and during supine bicycle exercise. Regional wall thickness and wall thickening of the systemic RV were assessed and compared with those of the left ventricle in healthy volunteers by two investigators working together. Regional wall parameters were calculated by using the three-dimensional centerline method. Independent-samples t test and paired-samples t test were used for statistical analysis. RESULTS: Ejection fraction of the systemic RV did not increase after exercise (56% +/- 8 at rest to 55% +/- 7 after exercise, P = .196). Mean RV wall thickening was impaired in patients with TGA at all levels both at rest and in response to exercise (P < .05). Moreover, the free wall and the anterior wall of the systemic RV had a smaller end-systolic thickness and a diminished thickening at rest and after exercise compared with findings in the normal left ventricle (P < .05). CONCLUSION: The systemic RV of patients after intraatrial correction for TGA reveals regional functional disturbances at rest and in response to exercise.

Adult↗
PubMed1987

Monitoring effects of alpha-human atrial natriuretic polypeptide (alpha-hANP) on left ventricular function in patients with essential hypertension with a cardiac probe.

The effects of alpha-hANP on left ventricular function were studied with a cardiac probe in ten patients with essential hypertension. Our data showed that intravenous administration of alpha-hANP significantly elevated left ventricular function. At 5 min, the elevation of EF, RCO, ER, RSV, PFR were 13.23% (P less than 0.02), 12.7 (P less than 0.02), 0.618 (P less than 0.02), 0.133 (P less than 0.05), 0.283 (P less than 0.01), respectively. At 10 min, the increase of EF, ER, were 11.07% (P less than 0.02) and 0.233 (P less than 0.01), respectively. Atriopeptin significantly reduced systolic and diastolic blood pressure from 2 min to 20 min (P less than 0.001-0.05).

Adult↗
PubMed2006

Effect of cilnidipine on left ventricular function in hypertensive patients as assessed by tissue Doppler Tei index.

Tissue Doppler Tei index is pointed to be more effective in the evaluation of global cardiac function than systolic and diastolic measurements alone in various heart diseases. This study was designed to assess the effect of cilnidipine on left ventricular function in hypertensive patients by using this index. A group of 40 hypertensives (mean age 55+/-8 years, range: 35-65) and 16 controls (mean age 52+/-9 years, range: 36-65) were included. Hypertensives were classified into non-left ventricular hypertrophy (NLVH) group (25 patients) and left ventricular hypertrophy (LVH) group (15 patients), and treated with cilnidipine for 2 months. Before and after treatment, the participants were examined by echocardiography. Tissue Doppler Tei index was calculated as diastolic time interval measured from end of late diastole to origin of early diastole (a') minus systolic Sm duration (b') divided by b', that is Tei index = (a'-b')/b'. Thirty-seven hypertensive patients finished the treatment. Tei index was significantly higher in NLVH and LVH groups than in control group, and in LVH group than in NLVH group (0.44+/-0.07 vs 0.28+/-0.06, P < 0.001; 0.51+/-0.13 vs 0.28+/-0.06, P < 0.001; 0.51+/-0.13 vs 0.44+/-0.07, P < 0.05). After treatment, Tei index was significantly decreased (0.40+/-0.11 vs 0.46+/-0.10, P < 0.0001); systolic blood pressure and diastolic blood pressure were also decreased significantly. In conclusion, Tei index is impaired in hypertensives before development of ventricular hypertrophy and impairment is more prominent in hypertrophy. Cilnidipine can improve left ventricular function. Tissue Doppler Tei index is gaining importance in evaluating LV function after drug intervention in hypertensive patients.

Calcium Channel Blockers↗
PubMed1999

Left ventricular function at rest and during bicycle exercise in normal subjects: assessment by ECG-gated myocardial perfusion SPET with 99Tcm-tetrofosmin.

99Tcm-labelled myocardial perfusion tracers allow simultaneous assessment of myocardial perfusion and left ventricular function using ECG-gated SPET. The aim of this study was to evaluate left ventricular performance during exercise by means of ECG-gated myocardial perfusion SPET. After the administration of 99Tcm-tetrofosmin (555-740 MBq), eight healthy volunteers aged 27-49 years underwent ECG-gated myocardial perfusion SPET at rest and during supine submaximal exercise (75 and 125 W), for 3 min each. Using ECG-gated SPET data, left ventricular end-diastolic volume (LVEDV) demonstrated a biphasic response during exercise (from 106.4 +/- 17.5 to 119.9 +/- 19.9 to 108.1 +/- 19.2 ml). In contrast, left ventricular end-systolic volume decreased gradually and significantly during exercise (from 47.1 +/- 11.9 to 41.5 +/- 8.9 to 36.1 +/- 10.1 ml; P < 0.05), and left ventricular ejection fraction continued to increase at higher workloads (from 56.1 +/- 6.0 to 63.0 +/- 2.7 to 67.0 +/- 4.3; P < 0.01) despite a fall in LVEDV. There was a progressive increase in cardiac output during exercise, which reached a peak of 7.2 +/- 0.9 l.min-1. We conclude that ECG-gated myocardial perfusion SPET can assess left ventricular function during exercise and may provide useful information for the evaluation of patients with ischaemic heart disease.

Adult↗
PubMed1990

Assessment of ventricular function in infants and children. Response to dobutamine infusion.

A method to assess ventricular functional reserve in infants and children unable to perform dynamic exercise was evaluated. Left ventricular ejection fraction was measured by radionuclide angiocardiography at rest and during infusion of dobutamine in 5-15 micrograms/kg/min dosages. The only side effects noted were arrhythmias in two patients, who had similar ectopy documented previously. Group left ventricular ejection fraction increased from 0.40 +/- 0.21 to a maximum of 0.49 +/- 0.24 (P less than 0.001). Left ventricular ejection fraction at 5 micrograms/kg/min (0.44 +/- 0.23) was not statistically different from that measured during infusion of dobutamine at 10 micrograms/kg/min (0.48 +/- 0.24). The six patients receiving anthracyclines, who had relatively low function at rest and increased function during dobutamine administration, were continued on their anticancer regimen without deteriorating in condition. Absolute values of left ventricular ejection fraction correlated best with the prognosis in patients with idiopathic dilated cardiomyopathy or structural abnormalities; six out of ten patients whose left ventricular ejection fraction never rose above 0.40 have either died or are in transplant protocols. Thus, study of left ventricular function can be performed easily during dobutamine infusion, generating valuable prognostic information.

Antineoplastic Agents↗
PubMed1997

Relationships between myocardial bioenergetic and left ventricular function in hearts with volume-overload hypertrophy.

BACKGROUND: Left ventricular (LV) hypertrophy secondary to volume overload can result in alterations in myocardial bioenergetics and LV dysfunction. This study examined whether bioenergetic abnormalities contribute to the pump dysfunction. METHODS AND RESULTS: Severe mitral regurgitation (MR) was produced in 10 dogs by disruption of the chordal apparatus. Hemodynamics and ventricular function were examined 11.7 months later under baseline conditions and during treadmill exercise. Myocardial high-energy phosphates were measured by using magnetic resonance spectroscopy at rest, during coronary vasodilation with adenosine, and during oxidative stress induced by rapid pacing and dobutamine. Chronic MR caused a 30% increase in LV mass and a 65% increase in LV volume. In MR animals, the hemodynamic and LV function were normal at rest, but abnormalities developed during beta-blockade and exercise. Myocardial creatine phosphate-to-ATP ratios were significantly lower in each layer across the LV wall in MR hearts than normal hearts. Myocardial blood flow and coronary reserve were normal in MR hearts. Moreover, hyperperfusion did not correct the abnormal bioenergetics. Despite altered bioenergetics at rest, the MR hearts tolerated rapid pacing and dobutamine infusion well. CONCLUSIONS: In volume-overloaded LV hypertrophied hearts, alterations in myocardial high-energy phosphate levels do not induce abnormal mechanical performance at rest but may be related to a decreased contractile reserve during exercise.

Adenosine Triphosphate↗