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PubMedDate not supplied

Regional left ventricular ejection fraction with single crystal gammacamera and gated equilibrium technique: repeatability and inter-observer variability.

Regional left ventricular ejection fraction calculated by means of gated blood pool scintigraphy was compared with that obtained from contrast ventriculography in a group of 20 patients, submitted to both procedures within a month. To evaluate repeatability both at rest and during stress, a second scintigraphic study was carried out after three weeks, with no change in drug regimen. Inter-observer variability was assessed in a randomly selected subgroup of 16 patients, in whom a computation was repeated by a second operator. Comparison of scintigraphic results showed a satisfactory agreement, and measurement agreement for global left ventricular ejection fraction was very good. As regards interobserver variability, each of the three myocardial segments examined (septal, lateral and infero-apical) showed good agreement. As regards repeatability, global left ventricular ejection fraction, proved readily reproducible both for rest and stress studies, with relatively small differences in observed values. Regional ejection fraction, on the other hand, had a high variability, especially during stress. It is suggested that for regional ejection fraction evaluation, reproducibility studies should be performed in order to better correlate result changes to clinical outcome after medical or surgical therapy.

Aged↗
PubMed2002

Predictors of right ventricular dysfunction in patients with coronary artery disease and reduced left ventricular ejection fraction.

BACKGROUND: The frequency and determinants of right ventricular (RV) dysfunction in patients with coronary artery disease (CAD) and reduced left ventricular (LV) function have not been thoroughly investigated. METHODS: The study population consists of 80 consecutive patients, invasively evaluated at our centre. Entry criteria were: LV ejection fraction < 45%; angiographic evidence of obstructive CAD; disease history of more than 3 months' duration. Exclusion criteria were: recent myocardial infarction and unstable angina. All patients underwent cardiac catheterization with coronary, LV and RV angiography. RV dysfunction was defined as a RV ejection fraction < 35%, which corresponds to the mean-three standard deviations of controls. RESULTS: Sixty-five patients (81%) had multi-vessel disease and 57 (71%) had a previous myocardial infarction. Mean LV ejection fraction was 31 +/- 8%. Mean RV ejection fraction was 46 +/- 11%. Right ventricular dysfunction was present in 14 patients (18%). An occluded proximal right coronary artery was associated with significantly lower RV ejection fraction (38 +/- 12% versus 47 +/- 10%; P = 0.009) but not LV ejection fraction (30 +/- 8% versus 32 +/- 9%; P = 0.444). However, at multivariate analysis, only pulmonary hypertension was an independent significant predictor of RV dysfunction (P < 0.001; OR: 1.13; CI: 1.06 -1.22). CONCLUSION: Right ventricular dysfunction in patients with chronic ischaemic LV dysfunction is detected in less than 20% of cases. Proximal right coronary artery occlusion is associated with a reduced RV ejection fraction. However, the role of right coronary artery disease is overwhelmed by the haemodynamic burden of pulmonary hypertension, which represents the only independent predictor of RV dysfunction in our population.

Aged↗
PubMed1992

Streptokinase induced defibrination assessed by thrombin time: effects on residual coronary stenosis and left ventricular ejection fraction.

OBJECTIVE: To evaluate laboratory markers of defibrination early after thrombolytic therapy and to determine their relation to residual stenosis and left ventricular ejection fraction measured angiographically before discharge from hospital. DESIGN: Prospective analysis of defibrination after streptokinase measured by fibrinogen assay and thrombin time to provide a comparison of these coagulation variables for predicting angiographic responses to treatment in patients with acute myocardial infarction. SETTING: The coronary care unit of a district general hospital. PATIENTS: 44 patients with acute myocardial infarction treated by streptokinase infusion, all of whom underwent paired blood sampling before and one hour after streptokinase and cardiac catheterisation at a median of six (interquartile range 3-9) days later. MAIN OUTCOME MEASURES: Assay of thrombin time and plasma fibrinogen concentrations one hour after streptokinase infusion. Relations between these coagulation variables and residual stenosis in the infarct related coronary artery and left ventricular ejection fraction. Separate analyses are presented for all patients (n = 44) and those with patency of the infarct related artery (n = 35). RESULTS: Streptokinase infusion produced profound defibrination in every patient as shown by changes in thrombin time and circulating fibrinogen. Thrombin time after streptokinase infusion correlated significantly with both residual stenosis (r = -0.43, p < 0.005) and left ventricular ejection fraction (r = 0.38, p < 0.02). The importance of these correlations was emphasised by the interquartile group comparison which showed that a thrombin time > or = 49 seconds predicted a residual stenosis of 74% and an ejection fraction of 65%, compared with 90% and 49% for a thrombin time < or = 31 seconds (p < 0.01). When the analysis was restricted to patients with patency of the infarct related artery, the correlation between thrombin time and residual stenosis remained significant and group comparisons continued to show that patients in the highest quartile range had more widely patent arteries and better preservation of ejection fraction. Analysis of the fibrinogen data, on the other hand, showed insignificant or only marginally significant correlations with these angiographic variables. CONCLUSIONS: Early after streptokinase infusion for acute myocardial infarction, the level of defibrination measured by thrombin time has an important influence on residual coronary stenosis and left ventricular ejection fraction at discharge from hospital, values above 49 seconds being associated with the best angiographic result.

Aged↗
PubMed1992

Increase in radionuclide left ventricular ejection fraction after cardioversion of chronic atrial fibrillation in idiopathic dilated cardiomyopathy.

To assess the potential improvement in left ventricular ejection fraction after cardioversion of chronic atrial fibrillation to sinus rhythm in idiopathic dilated cardiomyopathy, we studied prospectively 17 patients, aged 58 +/- 6 years, by radionuclide angiocardiography at rest. Left ventricular ejection fraction was determined before treatment and at a mean delay of 4.7 months after cardioversion. Return to sinus rhythm was obtained in 12 patients, pharmacologically or by electrical cardioversion. Five patients remained in atrial fibrillation. No clinical, echocardiographic or haemodynamic finding could predict the success of cardioversion. In chronic atrial fibrillation, the ejection fraction did not change significantly: 30.0 +/- 9.1% (19 to 44%) at the first evaluation and 29.5 +/- 8.3% (22 to 41%) after 4.7 months. After successful cardioversion, left ventricular ejection fraction improved from 32.1 +/- 5.3% (24 to 41%) to 52.9 +/- 9.7% (37 to 71%) (P less than 0.001). The difference was 20.8 +/- 11.3% and left ventricular ejection fraction was normalized in 50% (6/12) of the patients. There was a significant reduction in the cardiothoracic ratio on chest X-rays and of the left ventricular end-diastolic diameter on echocardiography; fractional shortening increased (27.7 +/- 4.3% vs 20.3 +/- 2.7%, P less than 0.01). A third evaluation was realized after a mean delay of 11.7 months in the patients with successful cardioversion. Sinus rhythm was present in 83% (10/12) of the patients: seven patients were reevaluated by radionuclide angiography. The improvement in left ventricular function observed at the 4.7 months evaluation was still present. In two patients with recurrence of atrial fibrillation, there was a severe deterioration of left ventricular systolic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1980

Effect of selective coronary arteriography on left ventricular volumes and ejection fraction in man.

This study was performed to assess the influence of selective coronary arteriography on left ventricular volumes and ejection fraction in man. In 30 patients with assorted cardiac diseases, left ventricular end-diastolic and end-systolic volumes and ejection fraction were quantitated immediately before and after selective coronary arteriography. In 19 patients (Group A), contrast left ventriculography was performed immediately before and after selective coronary arteriography. In the remaining 11 patients (Group B), multigated equilibrium blood pool imaging was performed just before and after coronary arteriography. In both groups, mean systemic arterial pressure and heart rate did not change from just before the first to immediately before the second assessment of left ventricular volumes and ejection fraction, but left ventricular end-diastolic pressure increased. End-diastolic and end-systolic volume indexes, and ejection fraction did not change from just before to immediately after selective coronary arteriography. Therefore, selective coronary arteriography (1) consistently causes an increase in left ventricular end-diastolic pressure but (2) exerts no effect on left ventricular volumes and ejection fraction, even in patients with severely compromised left ventricular function.

Adult↗
PubMed1995

Thallium-201 lung uptake and peak treadmill exercise first-pass ejection fraction.

Increased thallium-201 lung uptake immediately after exercise has been shown (1) to be a marker for extensive coronary artery disease, (2) to correlate with low rest and exercise left ventricular ejection fraction by supine gated blood pool scintigraphy, and (3) to be a powerful independent predictor of future cardiac events. Exercise left ventricular ejection fraction measured during upright exercise by the first-pass technique has also been shown to be a powerful independent prognostic variable. Combined perfusion and exercise left ventricular ejection fraction can be acquired by using the technetium 99m-based myocardial perfusion agents and offers an alternative protocol to stress/redistribution thallium imaging. It is therefore clinically important to understand the relation between exercise lung heart thallium uptake and exercise left ventricular ejection fraction. Accordingly, both these measurements were acquired in 38 patients with documented coronary artery disease who underwent two treadmill exercise studies. Parameters obtained from the first-pass study that are known to affect lung thallium uptake were correlated with exercise lung/heart thallium ratios; lung/heart ratios were used in a model to predict exercise left ventricular ejection fraction values. Exercise left ventricular ejection fraction and peak filling rate showed significant negative correlations with thallium lung/heart ratio, but the first-pass variables examined were not independently predictive of thallium lung uptake. The chance of finding an abnormal thallium lung/heart ratio at exercise LVEF of 40% is only 52%, whereas the chance of finding an abnormal ratio at exercise LVEF of 30% is 74%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

Calculation of the left ventricular ejection fraction by gated radionuclide angiography without direct background correction.

The mathematical characteristics of the cardiac background were studied in 50 patients who underwent both gated radionuclide angiography and cardiac catheterization. The background-corrected ejection fraction (BCEF) was calculated in the standard manner using an operator-defined periventricular background region. The "uncorrected" ejection fraction (UEF) was calculated from the uncorrected left ventricular time-activity curve and compared to both the BCEF and the angiographic ejection fraction (AEF), UEF exhibited remarkable linear correlation with both BCEF and AEF. The empirically determined linear regression equation, AEF = 2.18 (UEF) + 0.13, allowed calculation of a radionuclide ejection fraction corresponding to angiographic methods without direct background correction. When measurement of the left ventricular ejection fraction using this linear regression method was tested prospectively in 25 catheterized patients, the radionuclide regression ejection fraction showed excellent linear correlation with AEF (r = 0.85) and minimal inter-observer variability.

Adult↗
PubMed1994

Changes in left ventricular ejection fraction during transient myocardial ischaemia in patients with angina pectoris and silent ischaemia.

We compared the change in left ventricular ejection fraction during rest and exercise in 14 patients with angina pectoris and 14 patients with silent ischaemia. All patients had ischaemia defined as reversible defects at an exercise thallium myocardial scintigraphy. In the patients with angina pectoris the ejection fraction decreased from 44.0% (+/- 1 SD 13.4) at rest to 39.5% (+/- 1 SD 11.2) during exercise (p = 0.044). In the patients with silent ischaemia the ejection fraction decreased from 43.5% (+/- 1 SD 14.0) to 39.8% (+/- 1 SD 13.9) (p = 0.045). The fall in left ventricular ejection fraction in the two groups was almost identical (p = 0.77). This study confirms with a sensitive detection of transient ischaemia that silent ischaemia is accompanied with a fall in ejection fraction during exercise.

Adult↗
PubMed1985

[Determination of left ventricular global ejection fraction using ECG-gated cardiac computed tomography].

The left ventricular ejection fraction was calculated in 100 patients by means of ECG-gated cardio-CT and the results compared with those obtained by laevo-cardiography. A moderately good correlation of r = 0.736 was obtained. In general, CT under-estimated the ejection fraction. The normal range of the ejection fraction obtained by CT was 62.7% +/- 12.4%. Its specificity was high at 96%, but sensitivity was low, with 48.6%.

Adult↗
PubMed1987

Factors influencing the variations of ejection fraction during exercise in chronic aortic regurgitation.

The influence of left ventricular volume variations and regurgitant fraction variations upon left ventricular ejection fraction during exercise was examined using equilibrium radionuclide angiography in patients suffering from aortic regurgitation. Ejection fraction (EF), regurgitant fraction (RF), end diastolic volume (EDV) and end systolic volume (ESV) variations from rest to peak exercise were determined in 44 patients suffering from chronic aortic regurgitation (AR) and in 8 healthy volunteers (C). In C, EF increased (+0.10 +/- 0.03, P less than 0.01) and ESV decreased significantly (-23% +/- 12%, P less than 0.01), RF and EDV did not vary significantly. In AR patients, EF, EDV and ESV did not vary significantly because of important scattering of individual values. Changes in EF and ESV were inversely correlated (r = -0.79, P less than 0.01) and RF decreased significantly (-0.12 +/- 0.10, P less than 0.01). Volumes and EF changes during exercise occurred in three different ways. In a 1st subgroup of 7 patients, EF increased (+0.09 +/- 0.03, P less than 0.05) in conjunction with a reduction of ESV (-24% +/- 12%, P less than 0.05) without a significant change in EDV. In a 2nd group of 22 patients, EF decreased (-0.04 +/- 0.07, P less than 0.01) in association with an increase in ESV (+17% +/- 16%, P less than 0.01) and no change in EDV. In a 2nd group of 22 patients, EF decreased (-0.04 +/- 0.07, P less than 0.01) in association with an increase in ESV (+17% +/- 16%, P less than 0.01) and no change in EDV. In a 3rd subgroup of 15 patients, EF decreased (-0.02 +/- 0.06, P less than 0.01) despite a reduction in ESV (-7% +/- 6%, P less than 0.01) because of a dramatic EDV decrease (-10% +/- 6%, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Clinical application of ejection fraction by gated MRI.

To evaluate the clinical desired accuracy of the left ventricular ejection fractions (EFs) calculated by magnetic resonance imaging (MRI). Within one to three days post coronary angiography and left ventriculogram, twenty-five adults were studied by MR imaging. They had nuclear medicine studies for left ventricular ejection fractions as well. EKG-gated spin-echo 30-msec echo-delay images were obtained in end systole and end diastole in a plane parallel to the ventricular septum. Analysis of ventricular volumes and ejection fractions were performed using the area-length method. The EFs calculation by gated MRI were compared with that obtained by angiocardiography and nuclear medicine studies. The linear regression line obtained for ejection fraction was y = 0.858x +6.813, r = 0.753, p = 0.009; y' = 1.567x'-24.692, r' = 0.783, p' = 0.002. The above figure indicate a reasonable correlation among these three methods.

Humans↗
PubMed2006

Evaluation of left ventricular ejection fraction by the quantitative algorithms QGS, ECTb, LMC and LVGTF using gated myocardial perfusion SPECT: investigation of relative accuracy.

AIM: To compare the quantitative algorithms Emory Cardiac Toolbox (ECTb), quantitative gated SPECT (QGS), layer of maximum counts (LMC), and left ventricular global thickening fraction (LVGTF) using gated myocardial tomography in the calculation of the left ventricular ejection fraction using the regression without truth (RWT) technique. MATERIALS AND METHODS: Seventy-four consecutive patients were included in the study (59 males). All patients underwent stress-rest myocardial perfusion SPECT using Tc-tetrofosmin. Analysis of variance (ANOVA), the paired Student's t-test, the Pearson correlation coefficient and Bland-Altman were used for comparing the methods. The relative accuracy was performed by RWT. RESULTS: ANOVA revealed a significant difference among the methods in calculating the ejection fraction. RWT showed that ECTb and QGS outperformed the other two methods. The ECTb was slightly better than QGS, and LMC was slightly better than LVGTF. QGS and ECTb achieved good correlations in end diastolic volume, end systolic volume and ejection fraction measurements. One-way ANOVA demonstrated that QGS was the only software program affected by the category of the perfusion summed stress score (SSS), P=0.038. The ejection fraction determined by the QGS, ECTb and LVGTF methods correlated significantly with defect size (r=0.545, P<0.0001; r=0.530, P<0.0001; and r=0.419, P<0.0001, respectively), but the LMC method was not significantly correlated (r=0.216, P=0.067). CONCLUSIONS: There was a considerable variation among the quantitative gated SPECT methods in the evaluation of the ejection fraction. RWT revealed that the ECTb and QGS outperformed the other two methods with respect to the bias and precision of the measurements. Pair-wise correlations of the four methods ranged from mild to good with large agreement limits. Results of RWT provided important information in ranking the quantitative gated SPECT methods.

Algorithms↗
PubMed1975

Measurement of ejection fraction in man by videodensitometry.

This report describes a new method based on roentgen videodensitometry for the measurement of left ventricular ejection fraction in man. The net forward ejection fraction (NFEF) is calculated directly from the formula NFEF=1-exp(-.693/N), where N is the number of cardiac cycles necessary for half of the injected contrast material to be washed out of the left ventricle. The derivation of this formula is presented, and the technique is validated by comparison with washout curves from a Lucite model of the heart and with simultaneous angiographically determined left ventricular ejection fractions in man. The videodensitometry technique offers the following advantages over the conventional volume technique: (1) only a small amount of contrast material is required; (2) ectopic beats are uncommon during the washout phase when measurements are made; (3) the ejection fraction measured is an average of several cardiac cycles; and (4) dependence upon operator interpretation is minimized. Furthermore, given adequate mixing within the chamber, NFEF should be independent of ventricular geometry. Thus, NFEF of the unusually shaped left ventricle can be readily determined.

Absorptiometry, Photon↗
PubMed1987

Contrast echo washout curves from the left ventricle: application of basic principles of indicator-dilution theory and calculation of ejection fraction.

Time-intensity curves can be obtained from contrast echocardiography of the left ventricle. The purposes of this study were: 1) to verify whether these curves conform to the basic principles of indicator-dilution theory; and 2) to derive indexes of left ventricular ejection fraction from curve analysis. In seven closed chest dogs, 31 doses of the polysaccharide agent SHU-454 were injected into the left ventricular cavity during apical four chamber two-dimensional echocardiography. Data were obtained at different levels of ejection fraction, which were induced by changes in preload, afterload and contractility, and measured by single plane Simpson's rule analysis of digital subtraction left ventriculograms. In a subset of two dogs, eight incremental doses (from 1 to 8 ml) of SHU were injected in the basal state. Contrast echocardiograms were digitized off-line, the mean gray level/pixel of a region of interest inside the left ventricular cavity was measured, and the average value for three systolic frames of each beat was used to obtain time-intensity curves. A good correlation was observed between the peak of the time-intensity curve and the quantity of contrast injected (correlation coefficient r = 0.91 by a logarithmic fit). The echo intensities observed in each animal were subsequently transformed in quantity of contrast according to these functions and their natural logarithm was calculated both with and without background subtraction. All curves relating time and the natural logarithm of the corrected intensity exhibited a descending rectilinear portion (washout) in which the correlation was very good (r = 0.97 +/- 0.02 = mean +/- SD) and which was not significantly affected by background subtraction. The validity of this fit was also unaffected by heart rate (55 to 158 beats/min) and angiographic ejection fraction (22 to 74%), and only minimally influenced by duration of contrast washout (3.3 to 14.6 seconds). Ejection fraction was calculated by an algorithm derived from indicator-dilution theory: ejection fraction = [1 - e(-bd)] X 100, where b = slope of the curve and d = cardiac cycle duration. Linear regression analysis between values of ejection fraction derived by angiography and contrast echo yielded r = 0.73. A second index, based on b and d, was derived by multiple regression analysis. Linear regression analysis of this index and angiographic ejection fraction yielded a correlation of r = 0.87.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1999

[Validation of the three-dimensional method of sestamibi gated-SPECT in the calculation of the left ventricular ejection fraction in patients with ischemic heart disease. Comparison with contrast ventriculography].

INTRODUCTION AND OBJECTIVE: Tomography with acquisition synchronized with electrocardiography, gated-tomography, allows the assessment of left ventricular contractile function. The accuracy of a new method of gated-tomography, based on the three dimensional representation of the left ventricle to calculate the ejection fraction was validated by means of comparison with contrast ventriculography. METHODS: We studied 85 patients with ischemic cardiopathy, and ejection fraction was calculated by contrast ventriculography and sestamibi-gated-tomography, at rest and throughout 10 micrograms/kg/min of dobutamine. Furthermore, we assessed the extent of perfusion defect, as well as the number of segments with activity below 50% of the total 13 segments in which the tomographic slices were divided. RESULTS: Gated-tomography was significantly correlated to contrast ventriculography in the calculation of ejection fraction, both with acquisition at rest (r = 0.80) and throughout Dobutamine (r = 0.82). The average underestimation of gated-tomography calculation of ejection fraction was significantly greater for the rest study (-0.12 [IC 95% 0.04, -0.30]) than the dobutamine study (-0.07 [IC 95% 0.09, -0.24]). Patients with greater perfusion defects (4 o more segments) had no differences in underestimation of ejection fraction (-0.13 [IC 95% 0.03, -0.30] versus -0.11 [IC 95% 0.07, -0.29]). CONCLUSIONS: The three-dimensional method of gated-tomography accurately assesses the ejection fraction. The underestimation determined by this method was lower in the study done with viable doses of dobutamine. The extent of perfusion defect had no deleterious effect on gated-tomography in the calculation of ejection fraction.

Adult↗
PubMed1982

Effect of exercise and isoprenaline on left ventricular ejection fraction in patients with angina pectoris as assessed by radionuclide angiography.

The effect of supine leg exercise and an infusion of isoprenaline (2 micrograms/min) have been compared in 9 patients with angina pectoris and 8 normal control subjects. Left ventricular ejection fraction was measured by radionuclide angiography using the gated blood pool technique. The normal subjects increased their ejection fraction from 0.57 +/- 0.02 at rest to 0.71 +/- 0.02 during exercise, and 0.76 +/- 0.03 during isoprenaline infusion. In patients with angina pectoris, the resting ejection fraction of 0.47 +/- 0.04 decreased to 0.35 +/- 0.04 during exercise but increased to 0.63 +/- 0.06 during isoprenaline infusion. Our results suggest that the changes in ejection fraction probably depend on the changes in left ventricular segmental wall motion. When dyskinesia is increased, as with exercise, the ejection fraction declines, but when dyskinesia is unaffected or improved, as with isoprenaline, the ejection fraction increases.

Adult↗
PubMedDate not supplied

Automated ejection fraction determination from gated myocardial FDG-PET data.

BACKGROUND: The aim of this study was to determine the potential of the automated calculation of the left ventricular ejection fraction from gated myocardial positron emission tomography (PET) scans. METHODS: We retrospectively analyzed the data of 20 patients who underwent both gated fluorine 18 deoxyglucose (FDG)-PET and equilibrium radionuclide angiography (ERNA). Gated PET data were analyzed by 2 independent programs (ie, quantitative gated single photon emission computed tomography [QGS]) originally developed for gated single photon emission computed tomography studies and functional polarmap (FPM) originally developed for the analysis of (functional) dynamic PET studies. ERNA data were used as the gold standard. RESULTS: Both QGS and FPM left ventricular ejection fraction results correlated highly with ERNA (y = 0.90 x x-5.9, r = 0.86, P < .0001; y = 0.80 x x+3.3, r = 0.84, P < .0001, respectively). The correlation between FPM and QGS left ventricular ejection fraction results was even higher (y = 0.89 x x+8.6, r = 0.97, P < .0001). Bland-Altman plots showed systematic differences in the left ventricular ejection fraction of -9.6% +/- 7.5% (QGS vs ERNA), -3.8% +/- 7.8% (FPM vs ERNA), and -5.8% +/- 3.5% (QGS vs FPM). Further comparison of the left ventricular volumes revealed systematic difference between QGS and FPM. Our results indicate that the correlation between the different left ventricular ejection fractions shows little sensitivity to errors in the left ventricular volumes; however, the exact relationship is influenced by these errors. CONCLUSION: It is concluded that the automated determination of the left ventricular ejection fraction from gated PET data has significant potential; its results are highly and significantly correlated with ERNA. However, the methods presented here require additional calibration before final accuracy and clinical applicability can be determined.

Calibration↗
PubMed1978

[Infleunce of heart cycle length on left ventricular ejection fraction in normals and patients with coronary artery disease].

The ejection fraction is a clinically valuable index of left ventricular pump function. We investigated the influence of a change in heart cycle length in normals (gr. I) and in patients with coronary artery disease without (gr. IIa) and after myocardial infarction (gr. IIb) (atrial pacing 80 and 120 min-1). In all subjects ejection time decreased by ca. 17%. There was no statistical difference between the groups. Ejection fraction (mean absolute values): gr. I (n = 7): - 3.4% (n. s.), gr. IIa (n = 8): - 8.4% (p is less than 0.01), gr. IIb (n = 12): - 6.5% (p is less than 0.01), Gr. IIa + IIb: - 7.2% (p is less than 0.001), gr. I +IIA + IIb: - 6.1% (p is less than 0.001). Compared to the control value the relative decrease for all subjects was -12.3 +/- 12.0% (n = 27). When left ventricular performance is evaluated by ejection fraction using invasive and noninvasive methods (contrast medium ventriculography, echocardiography and scintigraphy) heart cycle length has to be taken into account. The data cannot be normalized by a simple mathematical procedure.

Cardiac Output↗