Factor analysis in left ventricular first-pass radionuclide angiography: value of the ventricular factor to measure ejection fraction

Summary Factor analysis theoretically generates the time-activity curves of the various physiological compartments, or factors, which are superimposed in a dynamic series of scintigraphic frames. An image of the spatial distribution of each of these factors is also displayed. We tested the ability of one of these, the ventricular factor, to measure the left ventricular ejection fraction (LVEF) in first-pass radionuclide angiography (FPRA). Forty-nine patients divided into three groups were studied. In a group of 32 patients, factor analysis was compared to a conventional scintigraphic method and to contrast angiography. The coefficient of correlation was similar for both techniques (r = 0.83). To test reproducibility, another group of 10 patients received two successive injections of Au-195m, three minutes apart. The reproducibility of LVEF was r = 0.78 with factor analysis and r = 0.81 with the conventional method. In a third group of seven patients, three successive injections of Au-195m were performed in the right and in the left anterior oblique projections. The reproducibility of LVEF was r = 071 with factor analysis. However LVEF was significantly lower in LAO than in RAO, 50 ± 11% vs 58 ± 17% respectively. It is concluded that factor analysis does not offer a more reliable means of calculating LVEF than a conventional method.This work was presented in part at the 31st Annual Meeting of the Society of Nuclear Medicine, Los Angeles, California, June 5–8,1984.     

Effects of angiographic contrast medium on left ventricular function: Evaluation by contrast angiography and radionuclide angiography

The purpose of this study was to evaluate the effect of angiographic contrast medium on left ventricular (LV) function in 26 patients undergoing diagnostic cardiac catheterization. Beat-by-beat analysis during contrast ventriculography showed that the ejection fraction (EF) was lower in the last beats than in the first beats (P <.02). Radionuclide angiograms were obtained the day before, as well as 15 to 65 minutes after catheterization, which included contrast ventriculography and coronary anteriography. The EF by radionuclide angiography was lower after catheterization than before (43 ± 14% vs 47 ± 17%, P <.01). The EF decreased by ≥ 5% in 11 of the 26 patients (42%) after catheterization. The decrease in EF in some patients was observed up to 65 minutes after catheterization and was not associated with symptoms or ST-T changes. The EF decreased in only one of nine patients who received nitroglycerin during catheterization, whereas it decreased in 10 of 17 patients who did not receive nitroglycerin (P <.05). The EF decreased in 9 of 14 patients (64%) who had normal resting LV function, whereas it decreased in only 2 of 12 patients (17%) who had abnormal resting function (P <.05). Thus, contrast material may depress LV function up to 1 hr and is more frequent in patients with normal resting EF. The use of nitroglycerin during catheterization may mask this effect.     

Estimation of left ventricular systolic function by nonvolumetric echocardiographic analysis in subjects with poor left ventricular visualization: A pilot study

Background: Accurate assessment of left ventricular (LV) systolic function is an essential requirement in clinical cardiology. Several echocardiographic methods provide quantitative analysis of LV volumes and ejection fraction (EF) based on the precise tracing of endocardial borders. Often, however, technically limited studies prohibit such direct analysis, and alternative techniques must be applied. Hypothesis: Nonvolumetric echocardiographic methods which do not require endocardial edge definition and tracing may accurately provide quantitative LV systolic function data. Methods: A pilot study was conducted to validate and compare two recently described indirect echocardiographic methods of LV systolic function analysis, with LVEF by radionu-clear cardiac angiography (RNCA). Thirty-two consecutive patients undergoing RNCA for clinical indications also underwent echocardiography within 24 h, with LV analysis performed by the techniques of (1) atrioventricular plane displacement (AVPD) and (2) mitral valve leaflet coaptation point to interventricular septum distance at end-systole (MVC-IVS). Results: Thirteen patients had an echocardiogram with poor two-dimensional visualization of LV endocardial borders. One patient could not be evaluated by the MVC-IVS method and two others by the AVPD method because of technical limitations. Chi-square analysis to compare how each method could discriminate between an RNCA LVEF of < or ≥ 50% demonstrated high correlations for the AVPD method (r = 0.6530, p < 0.0005) and the MVC-IVS method (r = –0.7029, p < 0.0001). Sensitivity, specificity, positive and negative predictive values, and test accuracy for the AVPD and MVC-IVS methods were 85 and 80%, 88 and 94%, 85 and 92%, 82 and 83%, and 83 and 87%, respectively. Conclusion: This pilot study demonstrates that both alternative echocardiographic methods may be useful in the assessment of LV systolic performance, even in the setting of poor LV endocardial border visualization. A larger study is warranted to apply and contrast these methods in different patient subsets.     

Evaluation of segmental left ventricular wall motion by equilibrium gated radionuclide ventriculography

The ability of equilibrium gated radionuclide ventriculography to detect segmental left ventricular (LV) wall motion abnormalities was determined in 26 patients undergoing cardiac catheterization. Multiple gated studies obtained in 30° right anterior oblique and 45° left anterior oblique projections, played back in a movie format, were compared to the corresponding LV ventriculograms. The LV wall in the two projections was divided into eight segments. Each segment was graded as normal, hypokinetic, akinetic, dyskinetic, or indeterminate. Thirteen percent of the segments in the gated images were indeterminate; 24 out of 27 of these were proximal or distal inferior wall segments. There was exact agreement in 86% of the remaining segments. The sensitivity of the radionuclide technique for detecting normal versus any abnormal wall motion was 71%, with a specificity of 99%. Equilibrium gated ventriculography is an excellent noninvasive technique for evaluating segmental LV wall motion. It is least reliable in assessing the proximal inferior wall and interventricular septum.     

Right ventricular size and function: The discrepancy between cardiac blood pool imaging techniques

The purpose of this study was to evaluate a number of equilibrium radionulide methods for analyzing right ventricular size and function, in an attempt to determine if any of a variety of approaches could accurately characterize right ventricular hemodynamics. Fourteen patients being clinically evaluated for coronary artery disease (N = 9), congestive cardiomyopathy (N = 2), valvular disease (N = 2), or intracardiac shunts (N = 1) underwent biplane contrast right ventriculography following gated blood pool imaging. Four radionuclide techniques were examined and included: (1) a semiautomatic edge-detection algorithm using a variable right ventricular region-of-interest and a right ventricular apical end diastolic background; (2) a fixed right ventricular end-diastolic region-of-interest with a C-shaped background; (3) the same fixed end-diastolic right ventricular region-interest with a right ventricular end-diastolic apical background; and (4) both right ventricular end-diastolic and end-systolic regions-of-Interest with a background chosen lateral to the left ventricle. Right ventricular end-diastolic volume was obtained by correcting end-diastolic counts by frame time, the number of processed heart beats, and blood radioactivity. The results illustrate the wide discrepancy among these methods. The correlation coefficients comparing right ventricular ejection fractions by radlonuclide methods 1 to 4 with contrast ventriculography were 0.23, 0.74, 0.40, and 0.42, respectively. For right ventricular end-diastolic volumes, the correlation coefficients were 0.90, 0.72, 0.90, and 0.92, respectively. While these techniques may be useful for analyzing serial changes in right heart function and size, further investigation is needed before right ventricular equilibrium radionuclide techniques can be acceptably utilized in clinical practice, particularly in individual subjects.     

平衡法门控心血池显像评价不同分级前壁心肌梗死患者左室收缩及舒张功能

目的我们应用平衡法门控心血池显像技术对不同Killip分级的前壁心肌梗死患者进行左室总体和局部收缩和舒张功能参数的对比分析。方法对照组15例（G0）,前壁心肌梗死KillipⅠ级17例（G1）,前壁心肌梗死KillipⅡⅢ级12例（G2）。利用平衡法门控心血池显像技术评价3组的左室总体和局部的收缩与舒张功能。结果①左室整体收缩功能,在LVEF,ESC 2个参数中,G1比G0有显著差异（P<0.05）,G2分别比G1和G0有显著差异（P<0.05）。在PER、1/3EF、1/3ER 3个参数中,G2分别比G1和G0显著下降（P<0.05）。②左室总体舒张功能,在PFR、1/3FF、1/3FR、EDC中,G1比G0有显著差异（P<0.05）,G2分别比G1和G0有显著差异（P<0.05）。③左室局部收缩功能,在以LVREF为参数时,G1在4个节段比G0显著差异（P<0.05）,G2在所有6个节段中比G1和G0均显著下降（P<0.05）。④左室局部舒张功能,在以LVR1/3FF为参数时,G1在4个节段比G0显著下降（P<0.05）,G2在所有6个节段比G0和G1均显著下降（P<0.05）。结论前壁心肌梗死后出现心功能受损或心力衰竭的主要原因为左室重构。     

Normal right ventricular systolic and diastolic function assessed by krypton-81m equilibrium ventriculography

Krypton-81m equilibrium ventriculography was used to study right ventricular function in 23 healthy male volunteers. Technetium-99m lung perfusion scintigraphy was employed to subtract radionuclide activity within lung during image analysis thereby enhancing image quality. The imaging technique was used to generate a time-activity curve for the right ventricle allowing the definition of indices of normal systolic and diastolic function for the right ventricle. At rest, indices of systolic ejection and diastolic filling were comparable to those previously reported for the left ventricle. Using this imaging technique, movement artifact during exercise reduces image quality and limits accurate measurement of these indices to resting studies.Abbreviations RVEF right ventricular ejection fraction     

Effects of molsidomine on global and regional left ventricular function at rest and during exercise in patients with angina pectoris

Although the antianginal properties of molsidomine are well-established, little is known about its effects on global and regional left ventricular dysfunction secondary to myocardial ischemia. In the present study, left ventricular performance was assessed by radionuclide ventriculography at rest and during exercise in 15 patients with coronary artery disease (CAD) and angina pectoris before and after the administration of 2 mg molsidomine sublingually. Gated blood pool studies were performed for evaluation of left ventricular ejection fraction (LVEF) and regional wall motion by analyzing amplitudes and phases of the first Fourier coefficient of regional time–activity curves. In contrast to normal subjects, during the control study period LVEF in patients with CAD decreased from 50.9% at rest to 42.7% during exercise (p<0.01). After molsidomine the resting values of LVEF increased slightly from 50.9% to 55.7% (p<0.05). Exercise values of LVEF increased from 42.7% to 51.3% (p<0.01). This is usually associated with amelioration of anginal pain and ischemic ST depression in the precordial ECG (0.15 mV vs. 0.09 mV; p<0.01). Before molsidomine, regional wall motion deteriorated from rest to exercise in 11 of 15 patients. These wall motion abnormalities usually expressed themselves as newly developed regions of left ventricular dysfunction (8 patients) or as accentuation of pre-existing contraction disturbances (3 patients). After molsidomine, regional wall motion did not show consistent changes at rest. Comparison during exercise showed enhanced regional function in 10 of the 15 patients after administration of the drug. At rest a slight but significant increase in heart rate was measured following molsidomine, whereas exercise heart rate remained unchanged. Only minor changes in systolic blood pressure occurred after molsidomine (rest, 143 mmHg vs. 134 mmHg; p<0.05; exercise, 177 mmHg vs. 174 mmHg; p>0.10). In conclusion, assessment of left ventricular performance at rest and during exercise in patients with CAD revealed significant improvement of global and regional left ventricular function, indicating reduction of myocardial ischemia. These effects may result primarily from reduction of left ventricular wall tension.     

Effect of pacing rate on regional left ventricular wall motion Assessment by quantitative analysis of equilibrium radionuclide angiography

We evaluated the hemodynamic impact of right ventricular pacing at different stimulation frequencies. Fourteen patients with a right ventricular pacemaker (VVI pacing with retrograde P wave) but without clinical and electrocardiographic evidence of coronary artery disease underwent two equilibrium radionuclide angiographies: one under low heart rate (50/60 beats per minute) and the other under fast heart rate (90/100 beats per minute). Left ventricular global and sectorial ejection fractions, amplitude and phase images of first harmonic, and sectorial phases of left ventricle were analyzed. In twelve patients (84.7%), sectorial ejection fraction abnormalities in the left ventricular apicoseptal and inferoapical regions were observed under low heart rate, and worsened under fast heart rate, while new onset sectorial ejection fraction abnormalities under fast heart rate were observed in the other two patients with normal sectorial ejection fraction under low heart rate. Sectorial ejection fractions of left ventricular apicoseptal and inferoapical regions significantly changed between low and high heart rate (–14.1±3.8%, p<0.005; –7.5 ±2.4%, p<0.01 respectively). Left ventricular sectorial phases were abnormal in only two patients (14.3%) under low heart rate, and in twelve patients (84.7%) under fast heart rate. Our study confirms that left ventricular regional wall motion abnormalities during VVI pacing significantly worsen under fast heart rate in comparison to those under low heart rate.     

Comparison of radionuclide angiography with three echocardiographic parameters of left ventricular function in patients after myocardial infarction

Aims. Left ventricular function is an important outcome measure in patients with coronary artery disease, in particular in patients after myocardial infarction. It is reliably assessed by radionuclide angiography, but echocardiographic wall motion scoring might be an attractive alternative. Methods. Four days after reperfusion therapy for acute myocardial infarction both radionuclide angiography and echocardiography were performed in 90 patients. Segmental wall motion scoring (WMSI) and visual estimation of the left ventricular ejection fraction (LVEF) was done by 2 independent observers. Repeated analysis was performed 1 month after the first reading. In 41 patients the LVEF was assessed quantitatively by tracing of endocardial outlines of the left ventricle. Results. Both correlation with radionuclide angiography (estimated LVEF: r = 0.71, WMSI: r = – 0.68, Tracing: r = 0.59) and inter- and intra-observer variability (estimated LVEF: 19% and 15%, WMSI: 65% and 59%) were in favour of the LVEF estimation method. Correlation with radionuclide angiography measurements was related to the quality of the echocardiogram and to the extent of coronary artery disease. Conclusion. Simple echocardiographic estimation of left ventricular ejection fraction in patients after reperfusion therapy for acute myocardial infarction proved to be superior to quantitative assessment of ejection fraction and to segmental wall motion scoring in comparison with radionuclide angiography.     

Intravenous streptokinase in acute myocardial infarction (I.S. A.M.): assessment of left ventricular function 1 and 7 months after infarction by radionuclide ventriculography

l.S.A.M. was a prospective, placebo-controlled, double-blindmulticentre trial of high-dose short-term intravenous streptokinasein acute myocardial infarction (AMI) within 6 h of the onsetof symptoms. Determination of left ventricular ejection fraction(LVEF) by radionuclide ventriculography was performed 1 and7 months after AMI in a subset of 192 patients at rest and,in 140 of them, also during exercise. Regional myocardial functionwas analysed in all 145 patients with neither a history of aprevious myocardial infarction nor revascularization proceduresor reinfarction within the 7-month follow-up period. One month after AMI, mean LVEF was higher in the streptokinasegroup in patients with anterior AMI (50±15% vs 42 ±16%,P = 0.013). This difference was more marked in the subgrouptreated within 3 h (53 ± 14% vs 42 ± 15%, P =0.004), whereas patients treated 3–6 h after the onsetof symptoms did not differ from respective controls (41 ±16%vs 41 ±18%). In patients with inferior A MI, the differencein mean LVEF was small (57±11% vs 55 ±12%, P =0.47). After anterior AMI benefit due to streptokinase therapywas preserved up to 7 months (52 ±14% vs 44 ±17%,P = 0.013). During exercise, the increase of mean LVEF was greaterin the streptokinase group at both dates, especially 7 monthsafter AMI (41 ±61% vs l.2±6.3%, P = 0.015). Instreptokinase-treated patients with anterior AMI, regional LVEFat rest was higher at both dates compared with controls, withinthe infarct zone as well as in remote myocardium. No treatment-controldifferences were demonstrable in patients with inferior AMI.During exercise, regional contractile reserve was better inthe streptokinase group within the infarct zone as well as inremote myocardium, irrespective of the site of infarction. Thus, intravenous streptokinase within 3 h after the onset ofA MI preserves global left ventricular function m anterior AMIover a period of at least 7 months. Intravenous streptokinaseimproves regional myocardial function within the infarct zoneas well as in remote areas. In inferior AMI investigation solelyat rest may underestimate the benefit of streptokinase therapy.     

核素心肌灌注显像与超声心动图测定青海地区老年冠心病患者心功能的对比研究

目的评价超声心动图(ultrasonic cardiography,UCG)与核素心肌灌注单光子发射计算机断层摄影(singlephoton emission computed tomography,SPECT)测定青海地区老年冠心病患者心功能的价值。方法选择老年冠心病患者240例.分别进行UCG和SPECT检测。根据SPECT显示的结果分为A组120例:心肌缺血;B组92例:小面积心肌梗死;C组28例:大面积心肌梗死。比较2种方法测定LVEF的相关性和一致性。结果 2种检测方法测得的LVEF在A组(r=0.71,P<0.05)、B组(r=0.69,P<0.05)有较好的相关性,而在C组无相关性(r=0.71,P>0.05)。A组与B组敏感性和特异性无明显差异。C组SPECT敏感性高于UCG,UCG特异性高于SPECT。结论青海地区老年冠心病患者中,心肌缺血和小面积心肌梗死者,临床上可以参考UCG测得的LVEF;而有多个节段的大面积心肌梗死患者宜采用SPECT测,以获得更准确的LVEF值和心肌灌注状况。     

Effects of projection and background correction method upon calculation of right ventricular ejection fraction using first-pass radionuclide angiography

Summary There is no consensus as to the best projection or correction method for first-pass radionuclide studies of the right ventricle. We assessed the effects of two commonly used projections, 30° right anterior oblique and anterior-posterior, on the calculation of right ventricular ejection fraction. In addition two background correction methods, planar background correction to account for scatter, and right atrial correction to account for right atrio-ventricular overlap were assessed. Two first-pass radionuclide angiograms were performed in 19 subjects, one in each projection, using gold-195m (half-life 30.5 seconds), and each study was analysed using the two methods of correction. Right ventricular ejection fraction was highest using the right anterior oblique projection with right atrial correction 35.6 ± 12.5% (mean ± SD), and lowest when using the anterior posterior projection with planar background correction 26.2 ± 11% (p<0.001). The study design allowed assessment of the effects of correction method and projection independently. Correction method appeared to have relatively little effect on right ventricular ejection fraction. Using right atrial correction correlation coefficient (r) between projections was 0.92, and for planar background correction r = 0.76, both p<0.001. However, right ventricular ejection fraction was far more dependent upon projection. When the anterior-posterior projection was used calculated right ventricular ejection fraction was much more dependent on correction method (r = 0.65, p = not significant), than using the right anterior oblique projection (r = 0.85, p<0.001). Comparison of the two methods currently used in clinical studies, showed no significant differences between the means, and r = 0.83 with a standard error of the estimate (SEE) = 7.4%. These data show that the calculation of right ventricular ejection fraction from right anterior oblique studies is less dependent on correction method, and suggest that its use as a standard method which will allow comparisons of results between centres.     

Comparison of echocardiography and radionuclide ventriculography in the follow-up of left ventricular systolic function in adult lymphoma patients during doxorubicin therapy

OBJECTIVES: To compare echocardiography (ECHO) and radionuclide ventriculography (RVG) in the monitoring of left ventricular systolic function during doxorubicin therapy in adult lymphoma patients. DESIGN: Prospective study. SETTINGS: University hospital. SUBJECTS: A total of 28 adult patients who received doxorubicin to a cumulative dose of 400-500 mg m(-2). MAIN OUTCOME MEASURES: ECHO and RVG were performed at baseline and after cumulative doxorubicin doses of 200, 400 and 500 mg m(-2). RESULTS: At baseline, the mean (+/-SE) left ventricular ejection fractions (LVEF) were 58 +/- 1.3, 71 +/- 1.8 and 58 +/- 1.7% as determined by RVG, M-mode ECHO and two-dimensional (2D) ECHO, respectively. After the cumulative doxorubicin dose of 500 mg m(-2) LVEF decreased to 49.6 +/- 1.7% (RVG) (P < 0.001), 62 +/- 1.6% (M-mode) (P=0.006) and 52.5 +/- 1.3% (2D ECHO) (P=0.036). Although a significant correlation between LVEF determined by RVG and M-mode ECHO (r=0.615, P=0.002) and a trend between RVG and 2D ECHO (r=0.364, P=0.096) were observed, there were substantial differences in the results of individual patients. In the agreement analysis using the method of Bland and Altman there was a mean difference of 12% units with the upper limit of agreement +26% units and the lower limit of agreement -2.1% units for LVEF determinations with M-mode ECHO and RVG, and a mean difference of 3.3% units with upper and lower limits of agreement +19.6 and -13.1% units for LVEF determinations with 2D ECHO and RVG, respectively. CONCLUSION: We found only a moderate agreement between left ventricular systolic function determined by ECHO and RVG methods. Thus, in the follow-up of left ventricular function in adult patients during doxorubicin therapy, the guidelines based on LVEF measurement by RVG cannot be applied to ECHO. Consequently, RVG remains the method of choice in this context.     

The acute effects of intravenous nisoldipine on left ventricular function within 24 h after acute myocardial infarction.

Nisoldipine is a calcium antagonist with potent coronary vasodilating effects in patients with chronic stable angina pectoris. We studied the acute effects of nisoldipine in six patients within 24 h (mean 14 +/- 4 h) after the onset of myocardial infarction. Nisoldipine was administered as a 4.5 micrograms kg-1 intravenous bolus over 3 min followed by intravenous infusion of 0.2 microgram kg-1 min-1 during 60 min. Radionuclide angiography, cardiac output and intra-arterial blood pressure measurements were performed before and during nisoldipine. Left ventricular ejection fraction increased from 48.3 +/- 10.3% to 55.3 +/- 11.8% (P = 0.034) during nisoldipine infusion. Regional wall motion score changed during nisoldipine infusion from 3.3 +/- 2.5 to 1.8 +/- 2.6 (P = 0.027). Cardiac output increased from 5.5 +/- 1.0 to 7.3 +/- 1.3 l min-1 (P = 0.0001). Heart rate increased from 78 +/- 12 to 88 +/- 11 beats.min-1 (P = 0.004). Mean arterial blood pressure decreased from 91.7 +/- 20.2 to 78.7 +/- 13.1 mmHg (P = 0.038). The rate-pressure product did not change significantly during nisoldipine infusion. It is concluded that nisoldipine improves global and regional left ventricular function in patients with acute myocardial infarction within the first 24 h. Our findings suggest that this effect is achieved without increasing myocardial oxygen demand.     

Postinfarction left ventricular pseudoaneurysm: echocardiographic diagnosis and prolonged survival in three patients

Both echocardiography and radionuclide angiography have been proposed as noninvasive modalities for the diagnosis of left ventricular pseudoaneurysm. In the only three cases seen at our institution over the past five years, this diagnosis was missed with radionuclide blood pool imaging, while two-dimensional echocardiography demonstrated the typical features of a pseudoaneurysm. Our patients were asymptomatic and diagnosis was made incidentally 4 to 6 years after myocardial infarction. Although the patients survived an extended period without surgery, the reported incidence of rupture is high, and prophylactic surgical repair probably is indicated. It is likely that the increased use of noninvasive cardiac imaging techniques will lead to the detection of other cases of unsuspected left ventricular pseudoaneurysm. Two-dimensional echocardiography appears superior to planar radionuclide ventriculography in establishing the diagnosis.     

Low-dose dobutamine radionuclide ventriculography for prediction of myocardial viability: quantitative analysis of regional left ventricular function

BACKGROUND: It is important to distinguish viable myocardium from necrotic tissue in order to decide upon therapy in patients with ischemic heart disease. HYPOTHESIS: We verified the hypothesis that quantitative analysis of regional left ventricular function using low-dose dobutamine radionuclide ventriculography (RNV) can sensitively predict myocardial viability and compared its usefulness with thallium-201 (201Tl) single-photon emission computed tomography (201Tl-SPECT). METHODS: Radionuclide ventriculography at rest and during low-dose dobutamine infusion (5 micrograms/kg/min), 201Tl-SPECT, and coronary angiography were performed in 51 subjects with severe ischemia-related stenosis of coronary arteries and 3 subjects without coronary artery disease. 201Tl uptake was assessed as normal (control), low perfusion (LP), or defect. We compared the response of regional function to dobutamine with the regional 201Tl uptake. The accuracy of both methods for identifying viable myocardium was investigated in 17 patients who underwent successful coronary revascularization, with a resulting improvement in wall motion. RESULTS: The increase in regional ejection fraction (delta r-EF) in response to dobutamine was significantly greater in the control (12 +/- 6%) and LP (16 +/- 11%) regions than in the defect (5 +/- 10%) regions. The increase in one-third regional ejection fraction (delta r-1/3EF) was also significantly higher in the control (14 +/- 7%) and LP (10 +/- 8%) regions than in the defect regions (5 +/- 6%). We defined myocardial viability as a delta r-EF > 5% or a delta r-1/3EF > 2%. The sensitivity and specificity of the delta r-EF for identification of myocardial viability were 91.4 and 55.5%, respectively. The sensitivity and specificity of the delta r-1/3EF were 91.4 and 66.6%, respectively; the corresponding values for 201Tl SPECT were 74.2 and 77.8%. CONCLUSION: Low-dose dobutamine RNV with quantitative analysis of regional left ventricular function was more sensitive for identification of viable myocardium than 201Tl-SPECT.     

Radionuclide assessment of a normal left ventricular response to exercise in patients without evidence of heart disease

The aim of this study was to define normal left ventricularperformance at rest and during supine bicycle exercise withequilibrium radionuclide ventriculography in a normal populationother than young healthy volunteers. Thirty-one patients (meanage 45 years ± 9 SD) with chest pain of varying originandno evidence of heart disease proven by means of noninvasiveand invasive techniques were studied. Left ventricular ejectionfraction (LVEF) at rest averaged 0.64 ± 007 SD and increasedwith peak exercise to 0.73 ± 008 SD (P<0.005). Changein LVEF from rest to maximum exercise ranged within 0–0.19.Six patients (19%) failed to augment LVEF with exercise to morethan 0.05; none of the patients dropped LVEF during exercise.Multivariate analysis revealed no significant predictors ofLVEF response to exercise. However, there was a tendency thatresting LVEF and enddiastolic volume index with exercise mightinfluence LVEF response to exercise. Peak left ventricular ejectionrate (LVER) at rest averaged 3.3s^–1 ± 0.6 SD andincreased to 51 s^–1 ± 11 SD (P<0.005) with exercise.Peak left ventricular early filling rate (LVFR) was 2.8s^–1± 0.6 SD at rest and was measured 5.5 s^–1 ±l.3 SD at maximum exercise (P<0.005). Left ventricular enddiastolicvolume (EDV) did not change significantly from rest to maximumexercise, whereas left ventricular endsystolic volume (ESV)decreased to 79% ± 19 SD (P<0.01) of the value atrest. In conclusion, in a normal population other than healthy youngvolunteers LVEF does not necessarily have to increase with exercise.Moreover, besides an augmentation of heart rate a normal leftventricular response to supine exercise is associated with anincrease of LVER and LVFR, a decrease in ESV and no significantchange in EDV, suggesting augmented contractility and a virtuallynegligible role of the Frank-Starling mechanism during exercise.     

Worsening of left ventricular diastolic function during long-term correction of anemia with erythropoietin in chronic hemodialysis patients – an assessment by radionuclide ventriculography at rest and exercise

We studied the effect of correction of anemia with erythropoietin on left ventricular systolic and diastolic function at rest and exercise in 17 chronic hemodialysis patients by means of maximum exercise testing and equilibrium gated radionuclide angiocardiography on three occassions: 1) initial–before erythropoietin administration, 2) intermediate–at the time when the target hemoglobin level reached 100 g/l, and 3) long-term–after 12 months of therapy. After correction of anemia, the patients showed a significant improvement in their response to exercise regarding maximal work load achieved, exercise duration and recovery time. Ejection fraction and peak ejection rate remained unchanged during therapy. At rest, peak filling rate was reduced from 2.62 ± 1.0 (baseline) to 2.28 ± 0.9 (intermediate) end-diastolic volume per second, p < 0.01, while no significant difference was observed during exercise. The time to peak filling rate was prolonged significantly during EPO therapy from 157 ± 30 to 177 ± 28 ms at rest, p < 0.05, and from 101 ± 24 to 130 ± 27 ms during exercise, p < 0.01. By the time of the late study, there were no significant differences between the late and intermediate study. In conclusion, amelioration of anemia with erythropoietin in hemodialysis patients produced improvement in exercise capacity, but diastolic function worsened with therapy and this effect was maintained during the long-term treatment, while systolic function at rest and exercise remained unchanged.     

Good correlation between gated single photon emission computed myocardial tomography and contrast ventriculography in the assessment of global and regional left ventricular function

Purpose: The purpose of this study was to determine the reliability of the measured left ventricular ejection fraction (LVEF) and wall motion analysis by the recently introduced quantitative electrocardiographically (ECG)-gated myocardial perfusion single-photon emission computed myocardial tomography technique (gated SPECT) (QGS). Materials and methods: We compared technetium-99 m tetrofosmin gated SPECT imaging and contrast ventriculography in the assessment of global and regional left ventricular function in 74 patients with undiagnosed chest pain of whom 27 sustained a previous myocardial infarction. Results: Linear regression analysis demonstrated that gated SPECT determined LVEF correlated well with LVEF determined from contrast ventriculography (y = 0.95x + 1.9, r² = 0.84, p < 0.0001). Bland–Altman plot analysis showed no systematic difference between the two sets of values derived from the two imaging approaches over a wide range of LVEF values. Exact agreement of segmental wall motion scores was 460 of 518 (89%) segments with a kappa value of 0.76 (p < 0.0001). Conclusion: We conclude that gated SPECT imaging is an accurate and reliable clinical tool to accurately measure global and regional left ventricular function.