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Simultaneous assessment of myocardial perfusion and left ventricular function during transient coronary occlusion.

OBJECTIVES: We used technetium-99m sestamibi imaging to evaluate the magnitude of changes in left ventricular function and perfusion and to investigate their interdependence during transient coronary occlusion. BACKGROUND: Transient coronary occlusion during coronary angioplasty provides a unique opportunity for examining the effects of acute myocardial ischemia on left ventricular function and perfusion. METHODS: Thirty-five patients with normal left ventricular function underwent first-pass radionuclide angiography with technetium-99m sestamibi using a multicrystal gamma camera during balloon occlusion of a coronary artery. Single-photon tomography was performed 2.1 +/- 1.7 h later. Subsequently, all scans were repeated at rest. RESULTS: The mean size +/- SD of the perfusion defect during coronary occlusion was 23 +/- 18%, with significantly larger defects observed for occlusions of the left anterior descending coronary artery (39 +/- 20%) than for occlusions of the left circumflex (15 +/- 11%) or right (15 +/- 9%) coronary artery (p < 0.05). The mean change in ejection fraction from recovery to occlusion was -17 +/- 17% and was significantly larger for left anterior descending (-26 +/- 21%) and left circumflex (-15 +/- 11%) than for right (-8 +/- 10%) coronary artery occlusions (p < 0.05). For the entire group, ejection fraction during occlusion correlated significantly with perfusion defect size (r = 0.63, p = 0.0004), whereas the extent of ischemic myocardium correlated with the decrease in ejection fraction (r = 0.69, p = 0.0001). The defects present during occlusion reversed within a few hours. CONCLUSIONS: Changes in left ventricular function and perfusion develop pari passu during coronary occlusion and are more severe when the left anterior descending artery is occluded. Although a significant correlation exists between the extent of the perfusion defect and the severity of the decrease in ejection fraction, there is a substantial individual variation with respect to changes in both myocardial perfusion and ventricular function during acute coronary occlusion.

Angina Pectoris↗

Exercise radionuclide assessment of left ventricular function before and after coronary bypass surgery.

The effects of elective saphenous vein coronary artery bypass surgery on left ventricular ejection fraction were assessed by using exercise first-pass radionuclide angiography in 66 consecutive patients. All patients with left main coronary artery or concomitant valvular disease were eliminated from the study. Before surgery, 7 patients had normal postexercise left ventricular function (Group 1), 33 had normal resting left ventricular function with an abnormal response to exercise (Group 2), and 26 had an abnormal resting left ventricular ejection fraction with an abnormal response to exercise (Group 3). Following surgery, patients in all three groups had no change in mean resting left ventricular ejection fraction; however, patients in Groups 2 and 3 had significant improvement in mean postexercise left ventricular ejection fraction (p less than 0.0001 and p less than 0.0054 respectively), whereas patients in Group 1 did not. Previous studies reported improvement in postexercise ejection fraction in patients with reduced resting left ventricular function and with an ischemic response to exercise (Group 3). But this is the first study to confirm improvement in postexercise function in patients with normal resting function and an ischemic response to exercise (Group 2).

Adult↗

Early beneficial effect of streptokinase on left ventricular function in acute myocardial infarction.

The effect of intravenous streptokinase therapy on the time course of functional recovery was investigated in a controlled study of 64 patients randomized within 3 hours after the onset of acute myocardial infarction (AMI). Contrast ventriculography was performed 1 to 4 days after AMI and repeated 5 weeks later. Wall motion was analyzed by the centerline method in the central infarct, peripheral infarct and noninfarct regions. In patients with ventriculographic data at the early catheterization, streptokinase-treated patients had less severe hypokinesia in the central infarct region than control patients (-2.9 +/- 0.9 [n = 29] vs -3.4 +/- 0.7 standard deviations below normal [n = 21], p less than 0.05). The benefit of streptokinase was more marked in the peripheral infarct region (-1.5 +/- 0.7 vs -2.1 +/- 0.6, p less than 0.001). As a result, the ejection fraction was slightly higher in treated versus control groups (46 +/- 10 vs 43 +/- 7%, respectively; difference not significant). At 5 weeks, function in the streptokinase and control groups had diverged further because of continued improvement in the streptokinase-treated patients. This study shows that streptokinase benefits left ventricular (LV) function by 1 to 4 days after AMI, earlier than previously reported. The benefit was not limited to the peripheral infarct region, where ischemia might have been less severe, but was also seen in the central infarct region. The implication is that thrombolytic therapy can improve LV function during the period of myocardial stunning, while myocardial function is still recovering.

Adult↗

Prediction of improvement in regional left ventricular function after coronary artery bypass grafting: quantitative stress-redistribution 201Tl imaging in detection of myocardial viability.

BACKGROUND: This study investigated the usefulness of quantitative assessment of Thallium-201 stress redistribution myocardial scintigraphy combined with quantitative assessment of regional left ventricular function using the centerline method for predicting of recovery regional left ventricular function following myocardial revascularization. METHODS: Twenty patients with chronic total obstruction of the proximal portion of left anterior descending artery and/or right coronary artery were studied. Percent Tl-uptake method was used to evaluate myocardial viability before CABG. Regional LV function was evaluated before and after CABG with the centerline method. The territory of LAD was defined by chords 10 to 58 and that of RCA was defined by chords 59 to 80 in the centerline method. The parameter of regional left ventricular function was the mean (SF-Av.)/SD of each LAD and RCA territory. RESULTS: In cases showing a % uptake value under 50%, the preoperative value of (SF-Av.)/SD was -3.18+/-0.74 and postoperative value was -2.63+/-0.8 1. The difference between these values was not significant. When the %uptake value over 50%, the preoperative value of (SF-Av.)/SD was -2.80+/-0.49 and the postoperative value was -2.27+/-0.28. The postoperative value was significantly higher than the preoperative value(p=0.007). CONCLUSIONS: Even in cases of severe left ventricular dysfunction, regional left ventricular function improved if the value of % uptake in the redistribution Thallium imaging was 50% or over. Quantitative analysis of myocardial scintigraphy combined with quantitative analysis of left ventriculography is a useful method for predicting recovery of regional left ventricular function following myocardial revascularization.

Aged↗

Efficient model-based quantification of left ventricular function in 3-D echocardiography.

Quantitative functional analysis of the left ventricle plays a very important role in the diagnosis of heart diseases. While in standard two-dimensional echocardiography this quantification is limited to rather crude volume estimation, three-dimensional (3-D) echocardiography not only significantly improves its accuracy but also makes it possible to derive valuable additional information, like various wall-motion measurements. In this paper, we present a new efficient method for the functional evaluation of the left ventricle from 3-D echographic sequences. It comprises a segmentation step that is based on the integration of 3-D deformable surfaces and a four-dimensional statistical heart motion model. The segmentation results in an accurate 3-D + time left ventricle discrete representation. Functional descriptors like local wall-motion indexes are automatically derived from this representation. The method has been successfully tested both on electrocardiography-gated and real-time 3-D data. It has proven to be fast, accurate, and robust.

Echocardiography, Three-Dimensional↗

Value of normal electrocardiographic findings in predicting resting left ventricular function in patients with chest pain and suspected coronary artery disease.

PURPOSE: Characterization of left ventricular function is important in managing patients with coronary artery disease. Although many methods are available to assess left ventricular function, most are either expensive, invasive, or both. In this study, we examined the ability of normal or near-normal resting electrocardiographic findings to predict resting left ventricular ejection fraction, measured by resting radionuclide angiography, in 874 patients with chest pain and suspected coronary artery disease. PATIENTS AND METHODS: A retrospective review was undertaken of 4,410 Mayo Clinic patients who underwent rest and exercise radionuclide ventriculography for the evaluation of chest pain and known or suspected coronary artery disease; of these, 874 patients met the inclusion criteria for the current study. A 15-lead electrocardiogram, which was interpreted by the cardiologist or cardiology trainee working in the laboratory, was obtained at the same evaluation as the radionuclide study. RESULTS: In 590 patients with no previous history of a myocardial infarction and entirely normal resting electrocardiographic results without nonspecific ST-T wave abnormalities, the mean left ventricular ejection fraction was 0.63 +/- 0.004, and 559 patients (95%) had a normal resting ejection fraction (defined as 0.50 or more). Both nonspecific ST-T wave abnormalities (p less than 0.001) and, to a lesser degree, a history of myocardial infarction (p = 0.06) were independent predictors of an abnormal resting ejection fraction. In 185 patients with nonspecific ST-T wave abnormalities and no history of myocardial infarction, the mean left ventricular ejection fraction was 0.61 +/- 0.009, and 85% had a normal resting ejection fraction. In 36 patients with nonspecific ST-T wave abnormalities and a history of myocardial infarction, the mean left ventricular ejection fraction was 0.53 +/- 0.021, and 72% had a normal resting ejection fraction. CONCLUSION: Thus, an entirely normal result on a resting 12-lead electrocardiogram in patients with suspected coronary disease but no history of a previous myocardial infarction is a reliable (95%) predictor of normal left ventricular function. If nonspecific ST-T wave abnormalities are noted, particularly if there is a history of a previous infarction, the predictive value of the electrocardiographic findings is diminished.

Angina Pectoris↗

Evaluation of left ventricular function in Kawasaki disease using equilibrium multigated blood pooling ventriculography.

Twenty-eight children ranging in age from 1-6 years (11 girls, 17 boys) with Kawasaki disease and, for comparison, 30 normal children ranging in age from 1-8 years (8 girls, 22 boys) without any cardiovascular disease were included in this study. The left ventricular functions of the children were evaluated by equilibrium multigated blood pooling ventriculography (EMBPV), which was performed after in vivo labeling of red blood cells using 10 mCi Tc-99m pertechnetate. Scintigraphy was performed using a digital gamma camera with the aid of an electrocardiogram gate. The left ventricular functions were determined by Fourier analysis of the time-activity curve in the left ventricles. The parameters of the left ventricular functions included: 1) systolic phase--[a] ejection fraction (EF), [b] ejection time (ET), [c] peak ejection rate (PER), and [d] first 1/3 ejection rate mean (1/3ERM), and 2) diastolic phase--[a] peak filling rate (PFR), [b] fast filling fraction (FFF), [c] time to peak filling rate (TPFR), and [d] first 1/3 filling rate mean (1/3FRM). The results showed that no significant differences existed between the two groups in any parameter of the left ventricular function. The authors suggest that the left ventricular functions in children with Kawasaki disease are not apparently impaired. The results were proven by the presentation of the EMBPV in this study.

Case-Control Studies↗

Effect of Terplex/VEGF-165 gene therapy on left ventricular function and structure following myocardial infarction. VEGF gene therapy for myocardial infarction.

BACKGROUND: We used a novel lipopolymeric gene delivery system, TeplexDNA, to transfect myocardium with plasmid vascular endothelial growth factor-165 (pVEGF) and evaluated the ability of pVEGF to preserve left ventricular function and structure after coronary ligation in a rabbit model. METHODS: New Zealand white rabbits underwent circumflex coronary ligation after direct intramyocardial injection of either Terplex alone or Terplex + 50 microg pVEGF-165. Serial echocardiography and histologic studies were performed (n = 12/group). Mortality did not differ between groups. The data is reported as the mean +/- standard deviation. RESULTS: Over the 21 days following coronary ligation, pVEGF-165-treated animals demonstrated significant improvement in fractional shortening (20-25%, p = 0.02), long axis two-dimensional ejection fraction (42-51%, p=0.02) and short axis m-mode ejection fraction (46-54%, p = 0.02). No significant improvements were noted in the control group. VEGF-treated animals had a 50% increase in peri-infarct vessel density and a trend towards a smaller infarct size (20% vs. 29%, p = 0.10). In animals receiving pVEGF-165, the diastolic ventricular area increased from 1.87 +/- 0.24 cm2 prior to ligation to 2.19 +/- 0.23 cm2 at 21 days following ligation, compared to an increase from 1.84 +/- 0.38 to 2.54 +/- 0.55 cm2 over the same period in control animals (p = 0.03). Similarly, the systolic ventricular area in VEGF-165 animals increased from 1.06 +/- 0.26 cm2 prior to ligation to 1.50 +/- 0.29 cm2 at 21 days following ligation, compared to an increase from 1.16 +/- 0.30 to 1.86 +/- 0.43 cm2 over the same period in the control animals (p = 0.04). CONCLUSION: TerplexDNA mediated delivery of plasmid VEGF administered at the time of coronary occlusion improves left ventricular function and reduces left ventricular dilation following myocardial infarction.

Animals↗

Predictive value of low dose dobutamine transesophageal echocardiography and fluorine-18 fluorodeoxyglucose positron emission tomography for recovery of regional left ventricular function after successful revascularization.

OBJECTIVES: This study was designed to assess the predictive value of myocardial viability diagnosed by dobutamine transesophageal echocardiography and fluorine (F)-18 fluorodeoxyglucose positron emission tomography for left ventricular functional recovery after revascularization in patients with chronic left ventricular dysfunction. BACKGROUND: The identification of akinetic but viable myocardium is of particular importance for the selection of patients with a compromised left ventricle who will benefit from coronary revascularization. METHODS: Multiplane rest and dobutamine transesophageal echocardiography (dobutamine, 5 and 10 microg/min per kg) studies and F-18 fluorodeoxyglucose positron emission tomographic studies at rest were performed in 2 patients with 1) previous myocardial infarction and regional akinesia, 2) a stenosed infarct-related coronary artery, and 3) a patent infarct-related vessel after revascularization. A basally akinetic segment was considered viable by transesophageal echocardiography if dobutamine-induced contractile reserve could be observed. Viability by positron emission tomography was defined as F-18 fluorodeoxyglucose uptake > or = 50% of the maximal uptake in a region with normal wall motion. Recovery of regional left ventricular function 4 to 6 months after revascularization was diagnosed by transesophageal echocardiography if > or = 50% of segments akinetic at baseline had improved wall thickening. RESULTS: Dobutamine transesophageal echocardiography identified viable infarct regions in 25 (59%) of 42 patients, and F-18 fluorodeoxyglucose positron emission tomography in 30 (71%) of 42 patients, yielding diagnostic agreement in 86% of patients. Sensitivity and specificity for prediction of left ventricular functional recovery in individual patients was 92% and 88%, respectively, for dobutamine transesophageal echocardiography versus 96% and 69% for F-18 fluorodeoxyglucose positron emission tomography. Segments remaining akinetic after revascularization had a significantly lower (p < 0.001) F-18 fluorodeoxyglucose uptake (48 +/- 15%) than that (73 +/- 15%) of segments with recovery of regional left ventricular function. CONCLUSIONS: Both dobutamine transesophageal echocardiography and F-18 fluorodeoxyglucose positron emission tomography were highly sensitive in predicting functional recovery of chronically kinetic or dyskinetic myocardium after successful revascularization. Thus, dobutamine transesophageal echocardiography is a clinically valuable alternative to F-18 fluorodeoxyglucose positron emission tomography for assessing residual viability and predicting functional recovery after revascularization.

Adrenergic beta-Agonists↗

[Effect of chronic amiodarone therapy on left ventricular function in dilated cardiomyopathy studied by the new Doppler-index].

UNLABELLED: Several noninvasive techniques have been used for the assessment of systolic and diastolic function. In most forms of cardiac disease however systolic and diastolic dysfunction coexist, hence a combined measure of left ventricular performance may be more reflective than their assessment alone. A recently recommended new Doppler index is supposed to be useful for this purpose. This index is the ratio of the sum of both isovolumic times and the ejection time. The objective of this study was to assess the features of the new index and then to prospectively evaluate the effect of chronic amiodarone treatment on left ventricular function using the new index and standard methods in dilated cardiomyopathy. RESULTS: Normal values of the new index are within a narrow range, it separates the normal and the dilated cardiomyopathy patients without overlap, it is not heart rate dependent in either group and it is not affected by either mitral regurgitation or left bundle brunch block. The index is inversely related to the relative diastolic filling time in both groups. In severe dilated cardiomyopathy after one year amiodarone treatment there was a significant decrease of heart rate, the new Doppler index and a significant increase of ejection fraction, ejection time and relative diastolic filling time. These changes were significant already at 1 month except the new index. These results suggest that the beneficial effect of amiodarone is due to the increase of diastolic filling time rather than to a positive inotropic effect. CONCLUSIONS: 1. The new Doppler index is simple and can be easily utilized in the differentiation of normal and abnormal left ventricular function: 2 chronic amiodarone treatment may be indicated even in the absence of arrhythmia to improve left ventricular function in severe heart failure.

Adolescent↗

Effect of oral disopyramide therapy on left ventricular function.

To study the effect of oral disopyramide therapy on left ventricular function, a subject of some controversy, we obtained first-pass radionuclide ventriculograms with a multicrystal gamma camera in 19 patients with or without therapy. Our findings demonstrated that disopyramide causes deterioration in left ventricular function in patients with abnormal ejection fractions. This effect is rarely recognized clinically and occurs despite safe therapeutic serum levels.

Administration, Oral↗

Echocardiographic evaluation of left ventricular function.

The ability of echocardiography to assess left ventricular function is entering an era of transition. Most existing data have been derived from M-mode measurements made along a single echo beam axis and, as such, were based on the assumption that the performance of the sampled segment represented that of the whole ventricle. The recent availability of two dimenensional echocardiography lessens the need to rely on this assumption.

Echocardiography↗

A theoretical comparison of first-pass and gated equilibrium methods in the measurement of systolic left ventricular function.

First-pass and gated equilibrium radionuclide studies of left ventricular function have proven extremely useful in the detection and management of patients with heart disease. Despite this practical experience, however, comparison of these methods generally has been confined to procedural differences that do not reflect the intrinsic properties of the methods. Here, we describe the results of a simple theoretical calculation from first principles that compares the methods based on their relative statistical precision. This analysis assumes that each procedure is carried out with the same tracer dose in the same hypothetical patient under identical conditions and with the same ideal imaging equipment. Results obtained with this model suggest that the imaging time required for a gated equilibrium study to achieve the same statistical precision as a first-pass study is typically less than 2 min in resting subjects and less than 1 min during stress. The analysis also indicates that gated equilibrium studies will tend to possess the greater statistical precision when cardiac output is elevated, such as when the heart is imaged during exercise. On the other hand, this analysis indicates that the first-pass method will tend to possess the greater precision when cardiac output is low and when imaging time is highly constrained.

Gated Blood-Pool Imaging↗

[Assessment of the left ventricular function in patients with pacemakers VVI and DDD, using non-invasive methods (systolic time)].

OBJECTIVE: Determination of left ventricular function, in patients with ventricular inhibited (VVI) and atrioventricular universal (DDD) pacemakers, by measurement of systolic time intervals. DESIGN: Twenty six patients were studied (six with DDD pacemakers and twenty with VVI pacemakers). In all of them systolic time intervals measurements were obtained the day before and one week after the implant. PATIENTS: We have studied twenty six patients consecutively, and all of them completed the study. INTERVENTIONS: The measurement of systolic time intervals was obtained, by the simultaneous recording of ECG, phonocardiogram and carotid arterial pulse. The recordings were obtained at a paper speed of 100 mm/sec. MEASUREMENTS AND RESULTS: The values obtained before the implantation were similar in both groups, but one week after implantation they show a closer to normal ventricular function, in patients with DDD pacemakers. CONCLUSIONS: The measurements of systolic time intervals, is a very easy method, to determine left ventricular function non invasively. In patients with DDD pacemakers, the left ventricular function, was better than in patients with VVI pacemakers.

Aged↗

Evaluation of left ventricular function in patients with aortic regurgitation using afterload stress.

Left ventricular function was assessed in 14 patients with chronic aortic regurgitation by afterload elevation with angiotensin. Seven of 14 patients maintained their resting ejection fraction with angiotensin (group A), while the remaining seven experienced a decline of greater than 0.10 in ejection fraction (group B). Six of seven group A patients showed an appropriate rise in left ventricular stroke work index in response to the angiotensin-induced rise in left ventricular end-diastolic pressure. In contrast, six of seven group B patients showed abnormal, flat, or declining stroke work indices. Included in the seven group B patients were two patients with left ventricular dysfunction secondary to coronary artery disease. The five other group B patients, who did not have coronary diseases, exhibited similar stress-induced ventricular dysfunction, despite the absence of any significant resting hemodynamic differences from patients in group A. These five stress-induced dysfunction patients were distinctive from patients who maintained their ejection fraction level in that the former all had regurgitant fractions of greater than 0.50, whereasl all gruop A patients had regurgitant fractions of less than 0.50. Similarly, these five stress-induced dysfunction patients had significantly larger left ventricular end-diastolic volumes than did the group A patients. These data suggest that patients with pronounced aortic regurgitation measured in terms of regurgitant fraction greater than 0.50 and left ventricular end-diastolic volume of greater than 160 cm3/m2 exhibit impaired ventricular function if appropriately stressed. As most of the patients with stress-induced dysfunction had a normal ejection fraction at rest, it may be that stress-induced dysfunction represents a stage before overt resting dysfunction and cardiac failure.

Adult↗

Effects of exposure to altitude on men with coronary artery disease and impaired left ventricular function.

The effects of altitude on coronary patients with impaired left ventricular function are virtually unknown and the question arises whether an exposure to altitude poses a risk to such patients. Twenty-three patients with coronary artery disease (mean age 51 +/- 9 years; group H) with a mean ejection fraction of 39 +/- 6% were compared with 23 normal subjects (mean age 53 +/- 6 years; group N). Both groups underwent a maximal symptom-limited bicycle stress test at 1,000 m and 2 days later at 2,500 m. In both groups, exercise capacity decreased significantly (group H, 1,000 m 162 +/- 28 W, 2,500 m 155 +/- 28 W, p = 0.02; group N, 1,000 m 205 +/- 28 W, 2,500 m 198 +/- 25 W, p = 0.02). Maximal heart rate and blood pressure did not differ between 1,000 and 2,500 m; oxygen saturation at rest and during exercise remained unchanged. At 2,500 m, the test was terminated more often because of dyspnea, but the level of perceived exertion (Borg) was similar to that at 1,000 m. There were no complications or signs of ischemia. Thus, patients with coronary artery disease with impaired left ventricular function without residual ischemia have good tolerance to exposure to altitude. The effects in patients are comparable to those in a group of normal subjects and the risk for an adverse event is not increased.

Adult↗