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PubMed1998

New modalities of regional and global left ventricular function analysis: state of the art.

Study of left ventricular (LV) regional and global function represents a main point of the cardiologic evaluation. This article presents an overview of the state of the art in quantitative analysis of ventricular wall motion and describes the different techniques available in clinical settings; we also present the personal experience of the authors in comparing conventional 2-dimensional (2D) echocardiography with other recently developed, more sophisticated techniques. Conventional 2D echocardiography mainly depends on the operator's ability. Moreover, the physiologic regional pattern of myocardial wall motion in different segments of left ventricle is still not completely known as well as the heart's rotational and translational movements. Qualitative and quantitative transesophageal echocardiography allows a better and more accurate evaluation of regional wall motion, and improves the on-line border detection feasibility even in patients with poor transthoracic echocardiographic window. The automated system for on-line endocardial border detection, color kinesis, and the power Doppler are, at the moment, promising techniques. Using magnetic resonance imaging as a "gold standard" for the study of global and regional left ventricular function, the investigators describe personal experiences with tissue Doppler imaging and a new computerized system for tissue Doppler images postprocessing analysis.

Adolescent↗
PubMed1996

Stretch-induced modifications of myocardial performance: from ventricular function to cellular and molecular mechanisms.

The purpose of this review is to give an integrative view of the effect of stretch on the myocardium from ventricular function changes to cellular and molecular mechanisms. The general approach will be to discuss the cellular and molecular events which can explain the findings obtained in the whole ventricle. Following the historical development, the classical analysis of the Starling mechanism and the basis of the length-dependent process are rapidly reviewed. We then analyze in greater detail the recent findings on the mechanisms of length-dependent activation changes in contractile protein affinity for calcium, changes in intracellular calcium release, action potential changes and stretch-activated ion channels and discuss the opposite effects of stretch on ventricular contraction (mainly deactivation shortening and viscoelastic properties of the myocardium). Besides the short-term contractile response to stretch, the longer-term effects of myocardial stretch which lead to ventricular hypertrophy will be also rapidly reviewed.

Animals↗
PubMed1995

The relationship of left ventricular geometry and hypertrophy to left ventricular function in valvular heart disease.

Valvular heart disease imposes a hemodynamic load on the left or right ventricle. This load is compensated by the development of ventricular hypertrophy. The pattern of hypertrophy which develops is characteristic of each type of valvular lesion with concentric hypertrophy compensating the pressure overload of aortic stenosis, eccentric hypertrophy compensating the volume overload of mitral regurgitation and both concentric and eccentric hypertrophy compensating the combined pressure and volume overload of aortic regurgitation. While these patterns are characteristic, there is substantial variation in the geometric distribution of hypertrophy among individuals with the same valvular disease. This variability in turn produces variability in the amount of compensation from patient to patient. The geometric pattern of hypertrophy which develops primarily affects left ventricular function as it relates to the Laplace equation. An increase in the radius to thickness ratio increases wall stress while a decrease in this ratio decreases wall stress. Discussed below are the mechanisms by which the various geometries that develop in valvular heart disease affect loading to become adaptive or maladaptive or both.

Aortic Valve Insufficiency↗
PubMed1993

Acute intravenous cocaine causes transient depression followed by enhanced left ventricular function in conscious dogs.

BACKGROUND: Prior studies in experimental canine models have demonstrated that intravenous cocaine administration causes myocardial depression. The purpose of the present study was to establish the mechanisms of cocaine's actions on myocardial and left ventricular performance after single intravenous bolus doses in conscious, chronically instrumented dogs, in which the full autonomic influences of cocaine would be manifest. METHODS AND RESULTS: In the intact state, cocaine (1 mg/kg) caused a transient decrease in left ventricular dP/dt (baseline; 3,086 +/- 107 mm Hg/sec; 2.5 minutes, 2,649 +/- 114 mm Hg; p < 0.05) followed by a 25 +/- 4% increase in left ventricular dP/dt that peaked at 15 minutes (left ventricular dP/dt, 3,751 +/- 127 mm Hg/sec, p < 0.01) and remained elevated during the 30-minute period of observation. Both the initial depression and the sustained increase in left ventricular contractile response were dose related. The increase in left ventricular dP/dt persisted under circumstances in which the responses were normalized for changes in heart rate and preload that accompanied cocaine administration. The positive inotropic effects were abolished by full autonomic or selective beta-adrenergic blockades. Finally, both cardiac output (baseline, 2,461 +/- 142 min/mL; peak [5 minutes], 3,434 +/- 218 mL/min; p < 0.05) and left ventricular stroke work (baseline, 39 +/- 5 g.m; peak, 49 +/- 6 g.m; p < 0.05) were increased at all times after cocaine administration, suggesting that pump performance was enhanced, despite early reductions in myocardial contractility. Similarly, indexes of early diastolic filling were enhanced despite transient early prolongation in isovolumic relaxation. CONCLUSIONS: Acute intravenous cocaine administration (0.1-2 mg/kg) has a biphasic effect on myocardial and left ventricular function with a transient depression followed by significant sustained increases in left ventricular contractility. The results are in keeping with an early local effect followed by significant adrenergic stimulation, which may be obscured by anesthesia or masked by changes in loading conditions.

Animals↗
PubMed2001

[Diagnosis of right ventricular function by transesophageal echocardiography].

Transesophageal echocardiography allows the complex structure of the right ventricle to be adequately visualized. Image analysis with specially designed software provides qualitative and quantitative information on right ventricular function, whether during surgery or in the intensive care unit, where the technique has proven particularly useful for early diagnosis of right ventricular insufficiency in patients receiving assisted ventilation. Loading conditions and degree of dysfunction of the right ventricle can be monitored in real time under various clinical conditions, significantly facilitation management.

Cardiac Output↗
PubMed2005

Left ventricular function in children with sleep-disordered breathing.

Severe obstructive sleep apnea in children leads to congestive heart failure. We studied the early changes in left ventricular function across a range of severity of the disorder. A dose-dependent decrease in diastolic function with increased severity of obstructive apnea was demonstrated.

Adolescent↗
PubMed1981

Left ventricular function in uremia: echocardiographic assessment in patients on maintenance dialysis.

Echocardiographic assessment of left ventricular function was performed in twenty-two unselected patients on stable, chronic maintenance dialysis. The statistically significant abnormalities were enlargement of the left ventricular cavity (end diastolic internal dimension or "diameter" 5.4 +/- 0.2 cm, normal 4.4 +/- 0.3 cm), thickening of the left ventricular wall (end diastolic thickness 1.1 +/- 0.05 cm, normal 0.9 +/- 0.03 cm) and a reduction in myocardial contraction (fractional shortening 28.2 +/- 2.0%, normal 35.7 +/- 0.9%). Myocardial impairment could not be attributed to the effects of hypertension or to ischemic heart disease. There was, however, a significant negative correlation between fractional shortening and total plasma catecholamines (r = 0.45, P less than 0.05) suggesting that excessive catecholamines may contribute to the decreased myocardial contraction seen in uremic patients.

Adolescent↗
PubMed2004

[Effects of a novel recombinant polypeptide from the sea anemone Anthopleura sp. on left ventricular function in New Zealand rabbits with chronic congestive heart failure].

OBJECTIVE: To observe the effects of recombinant hk2a, a novel neurotoxin from the sea anemone Anthopleura sp. on the left ventricular function in New Zealand rabbits with chronic congestive heart failure(CCHF). METHODS: CHF model was established using New Zealand rabbits by abdominal aortic coarctation. The left ventricular ejection fraction (LVEF) was measured by Acuson ultrasound systems (Sequoia 512) at 0, 5, 15, 30, 45 and 60 min respectively after intravenous injection with a single dose of recombinant hk2a (20 microg/kg x b x w.). The response of the rabbits to hk2a treatment was observed in comparison with that of the control group. RESULTS: Recombinant hk2a immediately and significantly increased the left ventricular ejection fraction of the rabbit models of CCHF after intravenous injection (P<0.05), and its effects were maintained for more than 1 h without affecting the heart rate. CONCLUSION: recombinant hk2a significantly increases the left ventricular ejection fraction in New Zealand rabbits with CCHF.

Animals↗
PubMed1986

Effects of elevated coronary sinus pressure on left ventricular function after the Fontan operation. An experimental and clinical correlation.

An experimental model was devised to evaluate the effects of elevated coronary sinus pressure on left ventricular performance. Thirteen mongrel dogs were used. The coronary sinus was cannulated and its entire blood flow diverted into a reservoir. The pressure in the coronary sinus was increased from 5 to 25 torr by elevating the drainage reservoir in a stepwise fashion. Cardiac index, coronary arteriovenous difference, rate of rise of left ventricular pressure, left ventricular systolic time intervals, and coronary blood flow were measured. When the coronary sinus pressure reached 15 torr, there was a significant decrease in cardiac index (3.60 +/- 0.5 to 2.70 +/- 0.6 L/min/m2, p less than 0.001), coronary blood flow (13.7 +/- 3.1 to 7.0 +/- 2.1 ml/min, p less than 0.001), rate of rise of left ventricular pressure (1,567 +/- 275 to 1,331 +/- 314, p less than 0.05), and an increase in coronary arteriovenous difference (62.8% +/- 9.3% to 70.5% +/- 5.4% saturation, p less than 0.03). These experimental results were correlated with postoperative catheterization findings in 24 patients with the Fontan procedure. Patients with a mean right atrial pressure less than 15 torr had a left ventricular ejection fraction of 93% +/- 6% of predicted, whereas patients with a right atrial pressure of 15 torr or more had a left ventricular ejection fraction of 75% +/- 13% of predicted (p less than 0.001). These experimental and clinical data strongly suggest that elevated coronary sinus pressure has deleterious effects on ventricular function after the Fontan procedure. Modifications of the procedure, such as using the rudimentary right ventricle when feasible or diverting coronary sinus flow to the pulmonary venous atrium, might decrease coronary sinus hypertension and improve long-term results.

Animals↗
PubMed2005

Left ventricular function parameters obtained from gated myocardial perfusion SPECT imaging: a comparison of two data processing systems.

BACKGROUND AND AIM: The Cedars-Sinai Quantitative Gated Single Photon Emission Computed Tomography (SPECT) (QGS) program, used to quantify left ventricular function parameters from gated myocardial perfusion scintigraphy (MPS), has been extensively validated and compared with other methods of quantification. However, little is known about the reproducibility of QGS on different processing systems. This study compared the findings of QGS running on workstations provided by two different manufacturers. METHODS: Gated rest MPS studies of 50 patients were analysed retrospectively. Filtered back-projection (FBP) was performed using identical parameters on Philips Pegasys and Nuclear Diagnostics Hermes workstations to produce gated short-axis (SA) slices. In addition, the gated SA slices reconstructed on the Pegasys were transferred to the Hermes. QGS was used to calculate the end-diastolic volume (EDV), end-systolic volume (ESV) and left ventricular ejection fraction (LVEF) in each case. RESULTS: The mean+/-standard deviation differences between the Pegasys and Hermes function parameters were -7.06+/-3.91 ml (EDV), -5.54+/-3.21 ml (ESV) and +1.14%+/-1.43% (LVEF) when data were reconstructed on different systems, and -0.16+/-1.58 ml (EDV), -0.10+/-1.02 ml (ESV) and +0.14%+/-0.73% (LVEF) when data were reconstructed on the same system. Bland-Altman plots showed definite trends for EDV and ESV for data reconstructed on different systems, but no trends were seen for data reconstructed on the same system. CONCLUSIONS: When data were reconstructed on two separate systems, the difference between the function parameters obtained from Pegasys and Hermes could be ascribed to differences in the reconstruction process on each system despite the use of identical parameters (filters, etc). However, when the same reconstructed data were analysed on both systems, no significant difference in left ventricular function parameters was observed.

Aged↗
PubMed2000

Predictive factors of ventricular fibrillation triggered by pause-dependent torsades de pointes associated with acquired long QT interval: role of QT dispersion and left ventricular function.

INTRODUCTION: Death due to acquired torsades de pointes usually is caused by ventricular fibrillation (VF), but the contributing factors to VF triggered by pause-dependent torsades de pointes are not understood. METHODS AND RESULTS: We evaluated 91 patients who fulfilled four criteria: (1) pause-dependent torsades de pointes; (2) prolonged QT interval and/or corrected QT (QTc) (>0.44 sec); (3) long-short initiation sequence; and (4) conditions known to induce pause-dependent torsades de pointes. There were 38 patients with a documented VF (group I) and 53 without VF (group II). Absolute and relative dispersions of QT and QTc were calculated based on the 12-lead standard ECG. Group I differed from group II with regard to myocardial infarction history (32% vs 13%; P = 0.035), left ventricular ejection fraction (44% +/- 14% vs 65% +/- 9%; P < 0.0001), presence of structural heart disease (100% vs 20.8%; P < 0.0001), QT mean (591 +/- 73 msec vs 514 +/- 78 msec; P < 0.0001), QTc mean (563 +/- 76 msec vs 508 +/- 90 msec; P = 0.002), absolute QT dispersion (166 +/- 56 msec vs 84 +/- 49 msec; P < 0.0001), relative QT dispersion (9.9% +/- 3.5% vs 6.3% +/- 3.2%; P < 0.0001), absolute QTc dispersion (158 +/- 57 msec vs 81 +/- 44 msec; P < 0.0001), and relative QTc dispersion (9.9% +/- 3.6% vs 6.2% +/- 3%; P < 0.0001). Multiple regression analysis showed that ejection fraction (P = 0.0001), presence of structural heart disease (P < 0.0001), and relative QTc dispersion (P = 0.038) were the only independent predictors of VF. CONCLUSION: Left ventricular function, presence of structural heart disease, and QTc relative dispersion should be evaluated carefully in patients with conditions susceptible to inducing torsades de pointes.

Aged↗
PubMed1986

Assessment of regional left ventricular function by magnetic resonance.

The ability of magnetic resonance to determine regional left ventricular function was investigated in 18 patients--13 with coronary artery disease (nine with previous infarction), one with congestive cardiomyopathy, one with mitral stenosis, one with an atrial septal defect, and two without detectable cardiac abnormality. Coronal magnetic resonance images were acquired through the aortic valve and sagittal images were acquired in the plane of widest diameter of the left ventricle seen in the coronal image, both at end diastole and end systole. Regional wall motion assessed by magnetic resonance was compared with the results of anteroposterior and left lateral x ray ventriculograms by two independent observers. The left ventricular wall was divided into three segments in each plane and the motion of the segments was classified as normal, hypokinetic, akinetic, or dyskinetic. Muscle thickness was measured in each segment of the magnetic resonance images and was considered to be abnormal if in the systolic images it was less than 75% of that in neighbouring segments or if it failed to increase by at least 25% between diastole and systole. Wall motion assessments by the two methods agreed in 68 of 105 segments analysed, but differed by one class in 32 segments and by two classes in five segments. The differences can be explained by the conditions under which the investigations were performed and by the disparity between a tomographic section and an x ray projection. Magnetic resonance showed 25 segments to have abnormal wall thickness. Only one patient with infarction did not have an area of wall thinning and no patient without infarction had an area of thinning. It is concluded that magnetic resonance allows an accurate non-invasive assessment of left ventricular wall motion and thickness.

Adult↗
PubMed2005

Comparison of segmental and global systemic ventricular function at rest and during dobutamine stress between patients with transposition and congenitally corrected transposition.

The aim of the study was to evaluate segmental and global right ventricular function at rest and during stress in patients having a systemic morphologically right ventricle. We studied 17 patients after atrial correction for transposition, 13 with congenitally corrected transposition, and 11 age-matched controls using cardiovascular magnetic resonance at rest and during stress with dobutamine given at 15 micrograms per kilogram per minute. Blood was drawn to obtain levels of brain natriuretic peptide. Right ventricular ejection fraction was calculated, and wall-motion and wall-thickening were assessed, in 4 segments of a midventricular slice. The findings for the systemic right ventricle were compared to the left ventricle in controls. Patients with transposition showed a decreased ejection fraction at rest (57 percent versus 69 percent, p equal to 0.005), decreased wall motion of the anterior, lateral and septal wall (p less than 0.01, p less than 0.01, and p less than 0.01) and decreased thickening of the lateral wall (p less than 0.01). Patients with congenitally corrected transposition showed normal ejection fraction, wall thickening, and wall motion at rest. During dobutamine stress, we found no significant differences in wall motion and thickening between the two groups. Ejection fraction, also increased to comparable values during stress, at 67 percent versus 66 percent, p not being significant. In both groups, we observed similarly increased levels of brain natriuretic peptide (p equal to 0.02 and 0.03, respectively). We conclude that only patients with transposition showed segmental wall motion and wall thickening abnormalities at rest. After dobutamine stress, however, segmental and global right ventricular dysfunction was similar in both groups.

Adolescent↗
PubMed2003

Left ventricular function and cardiovascular events following adjuvant therapy with adenosine in acute myocardial infarction treated with thrombolysis, results of the ATTenuation by Adenosine of Cardiac Complications (ATTACC) study.

BACKGROUND: Reperfusion therapy for acute myocardial infarction (AMI) reduces mortality but is also associated with reperfusion injury. The present study tested the hypothesis that adjuvant therapy with a low anti-inflammatory dose of adenosine might prevent reperfusion injury and preserve left ventricular function. METHODS: Six hundred and eight patients with ST-elevation AMI were randomised to receive infusions of adenosine (10 microg x kg(-1) x min(-1)) or placebo (saline) to be started with thrombolysis and maintained for 6 h. The primary endpoint was global and regional left ventricular systolic and diastolic function, as assessed by two-dimensional and Doppler echocardiography before hospital discharge. The secondary end-point was all cause and cardiovascular mortality, and non-fatal myocardial infarction during 12 months of follow-up. RESULTS: No beneficial effect of adenosine was found regarding echocardiographic indices of left ventricular systolic or diastolic function. Recruitment was stopped due to this apparent lack of effect after an interim analysis. However, after 12 months of follow-up, cardiovascular mortality was 8.9% with adenosine and 12.1% with placebo treatment [odds ratio (OR) 0.71, 95% confidence interval (C.I.) 0.4-1.2, P=0.2] among all patients and 8.4% vs 14.6% (OR 0.53, 95% C.I. 0.23-1.24, P=0.09) among patients with anterior AMI. All cause mortality differed similarly. Non-fatal AMI was not reduced similarly by adenosine treatment. Survival curves indicate that possible survival benefits are maintained after the first year of follow-up. CONCLUSIONS: Adenosine, given as adjunctive treatment with thrombolysis, did not provide detectable improvement of echocardiographic indices of left ventricular function when assessed before hospital discharge. Cardiovascular and all cause mortality appear to have been reduced by low-dose adenosine treatment, and the size of the effect appears to be clinically relevant (absolute risk reductions of approximately 4%). The power of the study regarding morbidity and mortality was, however, limited. The results are compatible with a beneficial anti-inflammatory effect of adenosine treatment on reperfusion injury after thrombolysis, which may be mediated by inhibition of leukocytes in peripheral blood. A larger trial is warranted to possibly establish beneficial effects of low-dose adenosine on survival after thrombolysis.

Adenosine↗
PubMed1993

[Delayed angioplasty for residual stenosis following thrombolyzed infarction: arterial permeability and left ventricular function after 6 months].

At medium term, the results of delayed angioplasty (DA) following intravenous thrombolysis (IVT) in terms of arterial permeability but particularly of left ventricular function (LVF) is still poorly understood and is the subject of this prospective study. Over 18 months, 76 patients underwent DA for the residual stenosis on day 8 +/- 5 with complete and partial success rates of 88.2% and 11.8% respectively. Rapid reocclusion (< 48 hours) was documented in 9.2% of cases. After 6 months, there had been no deaths and no recurrence of infarction but a recurrence of angina in 23.7% of cases. Angiographic monitoring, carried out in 56 cases (73.7%) after 6 +/- 2.4 months identified 21 restenosis (37.5%) and 6 re-occlusions (10.7%). 12 of the restenosis were successfully re-dilated. The effect on LV function was investigated in 50 patients. In the absence of reocclusion, the ejection fraction and the kinetics of the infarcted territory were improved; significant restenosis (> 60% by digital densitometry) did not appear to offset these improvements. In addition to the maintenance of arterial permeability, the possibility of functional recovery appears to be conditioned by the degree of contractile abnormality observed during the initial ventriculography. Despite the absence of restenosis after 6 months, the occurrence on day 6 of akinesia or above all of dyskinesia reduces the chances of contractile improvement with as a corollary more marked LV changes.

Angiography↗
PubMed1993

Study of left and right ventricular function in Romano-Ward syndrome.

OBJECTIVE: To examine left and right ventricular contraction in Romano-Ward syndrome: does abnormal myocardium affect the predisposition to arrhythmia? DESIGN: Tomographic radionuclide ventriculography was performed after the red blood cells were labelled conventionally with stannous pyrophosphate and technetium-99m. SETTING: Department of Nuclear Medicine, Aberdeen Royal Infirmary. PATIENTS: Eight subjects from two families known to have Romano-Ward syndrome, four of whom (two from each family) had had symptoms. RESULTS: The five subjects from family 1 had normal left ventricular contraction; two had subtle abnormalities of right ventricular phase. in family 2 all three subjects had abnormal left ventricular contraction (reduced amplitude in three, abnormal phase in two). All had subtle abnormalities of right ventricular phase. CONCLUSION: Abnormal right or left ventricular myocardium may be partly or wholly responsible for the repolarisation changes seen on the electrocardiogram of these families or may act as an ectopic focus to start ventricular tachycardias in a susceptible heart.

Adult↗
PubMed2003

Comparison of left ventricular function by echocardiogram in patients with Wilms' tumor treated with anthracyclines versus those not so treated.

The aim of this report was to evaluate late left ventricular function in survivors of Wilms' tumor and to compare patients treated with anthracyclines with those treated without anthracycline and with normal subjects. Wilms' tumor survivors treated without anthracycline had no myocardial abnormalities. A large percentage of patients treated with anthracycline presented with increased end-systolic wall stress. Results indicate that there is a high incidence of subclinical cardiovascular abnormalities in such patients.

Adolescent↗
PubMed2006

No incremental clinical information of NT Pro BNP at peak exercise over resting levels in patients with impaired left ventricular function.

There is an increasing tension to use NT Pro BNP blood levels at peak exercise testing. Their possible superiority over resting levels in congestive heart failure or factors associated with their increase have not been adequately studied. We studied 65 patients, 51 males and 14 females with impaired left ventricular function. Mean left ventricular ejection fraction (LVEF) was 35+/-9%. Our findings suggest that in patients with heart failure NT Pro BNP plasma levels at peak exercise do not provide incremental clinical information over resting levels. Baseline NT Pro BNP alone can provide sufficient clinical information.

Biomarkers↗