Sage Journals: Discover world-class research

Abstract

Objectives:

Left ventricular ejection fraction can be measured by a variety of invasive and non-invasive cardiac techniques. This study assesses the relation of three diagnostic modalities to each other in the measurement of left ventricular ejection fraction: invasive contrast left ventriculography, two-dimensional echocardiography, and quantitative gated single-photon emission computed tomography.

Methods:

Retrospective chart review was conducted on 58 patients hospitalized with chest pain, who underwent left ventricular ejection fraction evaluation using each of the aforementioned modalities within a 3-month period not interrupted by myocardial infarction or revascularization.

Results:

The mean left ventricular ejection fraction values were as follows: invasive contrast left ventriculography (0.44±0.15), two-dimensional echocardiography (0.46±0.13), and gated single-photon emission computed tomography (0.37±0.10). Correlations coefficients and associated p values were as follows: invasive contrast left ventriculography versus two-dimensional echocardiography (r=0.69, p<0.001), invasive contrast left ventriculography versus gated single-photon emission computed tomography (r=0.80, p<0.0001), and gated single-photon emission computed tomography versus two-dimensional echocardiography (r=0.69, p<0.001).

Conclusion:

Our results indicate that strong positive correlations exist among the three techniques studied.

Keywords

Cardiovascular radiology left ventricular ejection fraction quantitative gated single-photon emission computed tomography echocardiography contrast left ventriculography

Introduction

Left ventricular (LV) ejection fraction (LVEF) is an ejection phase index that is commonly used in the diagnosis and management of cardiovascular disease.^1–4 In addition, it provides valuable prognostic information for many cardiac disorders.^5–7 Multiple diagnostic techniques have been utilized to measure LVEF including invasive contrast left ventriculography (ICLV), two-dimensional echocardiography (2DE), quantitative gated single-photon emission computed tomography (gSPECT), first pass and equilibrium radionuclide left ventriculography, cardiac magnetic resonance imaging, and computed tomographic angiography.^3,8–18 LVEF is routinely measured in patients with established coronary artery disease and is often obtained during the evaluation of patients with chest pain.^8–18 In such patients, LVEF is frequently obtained using two or more diagnostic techniques, potentially producing redundant information about LV systolic function and increasing medical costs. In patients undergoing left heart catheterization with coronary angiography, ICLV exposes patients to additional radiation and to the risk of contrast-induced acute kidney injury.^19–21 Multiple studies have compared ICLV and individual non-invasive techniques for measuring LVEF.^22–41 Some have compared LVEF measurements utilizing two or three non-invasive cardiac techniques.^42–58 This study retrospectively compared LVEF in patients hospitalized for evaluation of chest pain, who underwent an ICLV, 2DE and gSPECT within 3 months of each other, not interrupted by myocardial infarction or by percutaneous or surgical coronary revascularization.

Methods

Patient selection

Patients hospitalized at the Harry S. Truman Memorial Veterans’ Hospital between 1 January 2002 and 31 December 2005 for chest pain thought to be of cardiac origin who received ICLV, 2DE, and gSPECT within 3 months of each another, not interrupted by percutaneous coronary intervention or coronary artery bypass grafting identified by retrospective chart review, were considered eligible for inclusion in the study. Diabetes mellitus was defined as a fasting blood sugar >126 mg/dL. Hypertension was defined as a systolic blood pressure >140 mmHg and/or a diastolic blood pressure >90 mmHg on at least two occasions or treatment with anti-hypertensive medication. Dyslipidemia was defined as elevated low-density lipoprotein or low levels of high-density lipoprotein cholesterol. Obstructive coronary artery disease was defined as coronary stenosis >50% on coronary angiography. Peripheral arterial disease was defined as ankle brachial index values <0.90 and/or classic Rose claudication. Cerebrovascular disease was defined as ischemic stroke or transient ischemic attacks. Chronic kidney disease was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m². Patients without chest pain and those who suffered from acute myocardial infarction or who underwent percutaneous coronary intervention or coronary artery bypass grafting prior to assessment of LVEF with all three diagnostic techniques were excluded from the study, as were subjects with technically inadequate studies of LVEF.

Protocol

Each patient underwent ICLV, 2DE, and gSPECT within 3 months of each other, not interrupted by myocardial infarction or by surgical or percutaneous myocardial revascularization.

ICLV was performed during left heart catheterization with coronary angiography in the 30° right anterior oblique position. About 30–35 mL of iodinated non-ionic, iso-osmolar contrast media was injected at a rate of 12–15 mL/s. Film speed was 30 frames/s. LV end-diastolic and end-systolic volumes were measured using the method of Sandler and Dodge.⁵⁹ LVEF (%) was calculated by subtracting LV systolic volume from LV end-diastolic volume, then dividing the difference by LV end-diastolic volume. The normal range for LVEF in our laboratory is 0.55–0.74.

Echocardiographic evaluation consisted of 2DE which was performed in accordance with American College of Echocardiography guidelines using an I-E 33 Philips echocardiograph (Andover, MA). All images were obtained by a single-skilled cardiac sonographer. LV volumes were measured using modified Simpson’s rule.⁶⁰ LVEF (%) was calculated by subtracting LV volume in systole from LV volume in diastole, then dividing the difference by LV volume in diastole. The normal range for LVEF in our laboratory is 0.55–0.70.

Quantitative gSPECT assessment of LVEF was determined during myocardial perfusion imaging using Tc99m sestamibi. Data were acquired using a three-head Prism 3000 camera (Picker, Cleveland, OH) or a two-head Forte camera (Philips, Milpitas, CA). Imaging with the three-head camera consisted of a 120° rotation and 30 stops/steps with 25–40 s per stop using low energy general purpose collimators. Quantitative analysis was performed with the gSPECT analysis program from Picker. Imaging with the two-head camera consisted of a 180° rotation and 32 stops/steps within 25–40 s per stop using high resolution vertex general purpose collimators. Images were corrected for attenuation using a transmission source of Gadolinium-153. Quantitative analysis was performed using AutoQUANT software from Philips Inc. Both methods used 8 frames per cycle in the gSPECT analysis. Tc99m was the radiopharmaceutical used to determine baseline LVEF in each patient. The normal range for gSPECT LVEF in our laboratory is 0.50–0.75.

LVEF for each technique was measured by a single experienced cardiologist or nuclear medicine physician. Each individual was blinded to the measurements obtained from the other techniques.

This research was approved by the Institutional Review Board of the University of Missouri-Columbia in accordance with the principles of the Declaration of Helsinki (approval number: 1020744).

Statistical analysis

Continuous variables were expressed as mean values ± 1 standard deviation. Mean LVEF values were reported as a decimal fraction ± 1 standard deviation. Linear regression analysis using Pearson correlation coefficients was used to compare LVEF values as follows: ICLV versus 2DE, ICLV versus gSPECT, and 2DE versus gSPECT. A p value of <0.05 was required for statistical significance.

Results

Patient characteristics

A total of 279 patients were evaluated for chest pain. LVEF was measured by ICLV, 2DE, and gSPECT in 186 patients. A total of 72 patients had all three techniques performed within 3 months of each other. Of these, 58 had no myocardial infarction or revascularization procedure before completion of LVEF analysis with all three modalities. Baseline demographic and clinical characteristics of the 58 patients entered into the study are summarized in Table 1.

Table 1.

Patient characteristics.

Characteristic	Mean value or N (%)
All patients	58 (100)
Male	57 (98)
Female	1 (2)
Age (years)	65±10
Diabetes mellitus	18 (31)
Hypertension	39 (67)
Dyslipidemia	29 (50)
Cigarette smoker	10 (17)
Normal coronary arteries or non-obstructive coronary artery disease	34 (59)
Obstructive coronary artery disease	24 (41)
Peripheral arterial disease	10 (17)
Cerebrovascular disease	4 (6)
Chronic kidney disease	7 (12)

Age is expressed as mean value ± 1 standard deviation.

Other characteristics are expressed as number of patients (N) and percentage of the total study population (in parentheses).

Assessment of LVEF

Mean LVEF values ± 1 standard deviation for the three modalities studied were 0.44 ± 0.15 for ICLV, 0.46 ± 0.13 for 2DE, and 0.37 ± 0.10 for gSPECT. In our laboratories, the lower limits of normal for LVEF were 0.55 for ICLV and 2DE, and 0.50 for gSPECT. Correlations among the three modalities were as follows: ICLV versus 2DE (r = 0.69, p < 0.001, Figure 1); ICLV versus gSPECT (0.80, p < 0.0001, Figure 2), and 2DE versus gSPECT (r = 0.69, p < 0.001, Figure 3).

Figure 1.

Correlation of LVEF values derived from invasive contrast left ventriculography and LVEF values obtained from two-dimensional echocardiography.

Figure 2.

Correlation of LVEF values derived from invasive contrast left ventriculography and those obtained using gSPECT.

Figure 3.

Correlation of LVEF values derived from two-dimensional echocardiography and LVEF values obtained using gSPECT.

Discussion

Accurate assessment of LVEF is important due to its prognostic value and its ability to direct pharmaceutical and device therapy, particularly in patients with coronary artery disease and in those with heart failure.^1–8 Many patients with chest pain thought to be of cardiac origin undergo left heart catheterization with coronary angiography and ICLV. Witteles et al.⁸ reported that ICLV was performed in 81.1% of 96,235 patients undergoing coronary angiography. ICLV increases exposure to ionizing radiation and may contribute to the development of contrast-induced acute kidney injury in at-risk patients such as those with underlying renal dysfunction, diabetes mellitus, anemia, hypotension and shock, and heart failure.^8,19–21 During the course of clinical evaluation, multiple non-invasive cardiac procedures capable of generating LVEF values are frequently performed. In such patients, ICLV may provide redundant information concerning LV systolic function, if LVEF measurements obtained using non-invasive cardiac techniques are accurate and comparable to those obtained from ICLV. If so, non-invasive assessment of LVEF could be substituted for ICLV, thus reducing radiation exposure, cost, and the risk of contrast-induced acute kidney injury.

Many studies have compared LVEF values obtained from various non-invasive imaging techniques with those obtained using ICLV.^22–41 Prior studies, like ours, reported mean LVEF values and binary correlations between imaging techniques.^22–41

Our study demonstrated that mean LVEF values obtained from 2DE were nearly equal to those obtained from ICLV. Similar observations were reported by Murarka et al.,³⁰ Godkar et al.,⁴¹ and Joffe et al.²⁹ In contrast, mean LVEF values obtained using 2DE were lower than those obtained using ICLV in studies reported by Albrechtsson et al.,²⁸ Nichols et al.,³⁸ and Hoffman et al.²⁷ In Hoffman’s²⁷ study, mean LVEF values were higher and more comparable to those obtained with ICLV when contrast echocardiography was employed. LVEF values from ICLV correlated positively and significantly with those obtained from transthoracic echocardiography in nearly all studies. Correlation coefficients ranged from 0.23 to 0.96, with most ranging from 0.75 to 0.80.^22–41 The correlation coefficient reported in our study (0.69), while statistically significant, was among the lowest of those reported. Murarka et al.³⁰ reported an overall correlation coefficient of 0.36 (p < 0.001). In this study, the correlation coefficients were 0.23 (not significant) in patients with non-ischemic dilated cardiomyopathy and 0.75 (p < 0.0001) in those with ischemic cardiomyopathy.³⁰

Studies comparing LVEF values obtained from ICLV and gSPECT have expressed the relationship primarily in the results of linear regression analyses.^{22,23,36–40} Reported correlation coefficients range from 0.75 to 0.94, all of which were statistically significant.^{22,23,36–40} The correlation coefficient reported in this study (0.80) is in line with these results. Our study showed that gSPECT produced a lower mean LVEF value (0.37 ± 0.10) than ICLV (0.46 ± 0.13). However, the lower limit of normal for gSPECT LVEF (0.50) in our laboratory is 0.05 lower than that of ICLV. Godkar et al.⁴¹ reported higher mean LVEF values associated with gSPECT compared to those associated with ICLV (0.54 ± 0.12 vs 0.46 ± 0.13). The reasons for this disparity are uncertain. Speculation exists that alterations in LV geometry (global and regional) and differences among various gSPECT protocols and radionuclide agents used may contribute to variability in LVEF measurement with gSPECT relative to standard right anterior oblique ICLV.

Studies comparing LVEF values obtained from 2DE and gSPECT have reported variable results.^22,42–47 In a study of 109 patients, Cwaig et al.⁴⁵ reported no significant difference in mean LVEF values obtained from 2DE (0.59 ± 0.16) and gSPECT (0.58 ± 0.15). Similarly, Berk et al.⁴³ reported no significant difference between mean LVEF values obtained from 2DE (0.29 ± 0.08) and those obtained using gSPECT (0.28 ± 0.09) in 45 patients with dilated cardiomyopathy. Habash-Bselso et al.²³ reported a small but significant difference in mean LVEF values from 2DE (0.49 ± 0.01) and those obtained from gSPECT (0.47 ± 0.10, p = 0018). A larger disparity in mean LVEF values was noted in a study of 63 patients by Omar et al.⁴² In that study, mean LVEF values were 0.56 ± 0.05 with 2DE and 0.51 ± 0.09 with gSPECT. In contrast, Mistry et al.⁴⁴ reported higher mean LVEF values with gSPECT (0.64) than with 2DE (0.56) in 50 patients. Our findings showed mean LVEF values of 0.46 ± 0.13 with 2DE and 37 ± 10% with gSPECT. This difference could be explained in part by the fact that in our laboratory, the lower limit of normal for LVEF derived from gSPECT is 0.05 lower than that of 2DE. Several studies, including ours, have reported significant positive correlations between LVEF values obtained from 2DE and gSPECT with r values ranging from 0.72 to 0.80.^{22,23,42–47,49,50}

We found only one other study that evaluated and compared resting LVEF values determined using ICLV, 2DE, and gSPECT. In a study of 109 patients with coronary artery disease, Gholamrezanezhad et al.²² reported the following mean LVEF values at rest: ICLV (0.42 ± 0.12), 2DE (0.45 ± 0.12), quantitative gSPECT (0.47 ± 0.15), and semi-automatically processed gSPECT (0.43 ± 0.14). All correlation coefficients were >0.63 and were statistically significant.

Our study focused on the three most commonly used modalities for measuring LVEF: ICLV, 2DE, and gSPECT. Other diagnostic techniques have produced variable results. LVEF values derived from equilibrium radionuclide left ventriculography, magnetic resonance imaging, and computed tomographic angiography imaging have, in general, correlated positively and significantly with ICLV, 2DE, and gSPECT and with one another.^{3,17,18,27,32,39,44,46,48–53} However, mean LVEF values derived from equilibrium radionuclide left ventriculography, magnetic resonance imaging, and computed tomographic angiography have varied substantially when compared to ICLV, 2DE, and gSPECT, lower in some studies, nearly equal in several studies, and higher in other studies.^{3,17,18,27,32,39,44,46,48,50,53,56}

There were multiple study limitations. Although consecutive eligible patients were enrolled, the study was retrospective. All but one of the patients enrolled were middle-aged or older men and thus, the findings may not be applicable to women and younger men. Two different cameras were used to acquire gSPECT images. There were no comparisons with standard techniques such as equilibrium radionuclide left ventriculography or newer technologies such as magnetic resonance imaging. Although the study was adequately powered, a larger patient population would have imparted greater strength to the observed outcomes. Data analysis for each method was performed only once by a single different investigator for each technique. This precluded intra- and inter-observer variability analysis.

Our results indicate that there are strong positive correlations in LVEF among the three modalities employed in this study. The correlations of 2DE and ICLV (Figure 1), gSPECT and ICLV (Figure 2), and gSPECT and 2DE (Figure 3) were highly significant, all p < 0.001. This study is only the second to compare LVEF values using ICLV, 2DE, and gSPECT in the same study population. The lower mean LVEF value for gSPECT can be explained, in large part, by the fact that the lower limit of normal in our laboratory for gSPECT LVEF was 0.05 lower than that of ICLV and 2DE. It is noteworthy that the absolute value of the gSPECT LVEF measurement is determined by the sum of the components of the system: patient, camera, collimator, protocol, radiopharmaceutical, and software. Differences in methodology may contribute to variations in normal range values among individual laboratories.

In summary, our results indicate that there is strong positive correlation among the three techniques used to measure LVEF in this study. This suggests that 2DE and gSPECT can be used to accurately assess LVEF in patients undergoing coronary angiography, in patients who may be at risk of contrast-induced acute kidney injury or excessive radiation exposure, taking into account variation in normal range values among individual laboratories that may exist due to differences in methodology.

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Ethics approval

Ethical approval for this study was obtained from the Institutional Review Board of the University of Missouri-Columbia: Approval number 1020744.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Informed consent

Informed consent was not sought for this study because this was a retrospective chart review study. Patients were identified by medical record number only.

References

San Roman

Candel Riera

Arnold

. Quantitative analysis of left ventricular function as a tool in clinical research, theoretical barrier of methodology. Rev Esp Cardiol 2009; 62: 535–551.

Tak

. Ejection fraction derived by noninvasive modalities versus left ventricular angiographic determination. Clin Med Res 2005; 3: 61–62.

Chandra

Skali

Blankstein

. Novel techniques for assessment of left ventricular systolic function. Heart Fail Rev 2011; 16: 327–337.

Bax

Wijns

Cornel

. Accuracy of currently available techniques for prediction of functional recovery after revascularization in patients with left ventricular dysfunction due to chronic coronary artery disease: comparison of pooled data. J Am Coll Cardiol 1997; 30: 1451–1460.

Brophy

Dagenais

McSherry

. A multivariate model for predicting mortality in patients with heart failure and systolic dysfunction. Am J Med 2004; 116: 300–304.

Curtis

Seth

Yongfei

. The association of left ventricular ejection fraction, mortality, and cause of death in stable outpatients with heart failure. J Am Coll Cardiol 2003; 42: 736–742.

Volpi

De Vita

Franzosi

. Determinants of 6-month mortality in survivors of myocardial infarction after thrombolysis. Results of the GISSI-2 data base. The Ad hoc Working Group of the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardico (GISSI)-2 Data Base. Circulation 1993; 88: 416–429.

Witteles

Knowles

Perez

. Use and overuse of left ventriculography. Am Heart J 2012; 163: 617–623.

Seiagra

Leoncini

. Gated single photon emission computed tomography. The present-day “one-stop-shop” for imaging. Q J Nucl Med Mol Imaging 2005; 49: 19–29.

10.

Berman

Germano

. The clinical value of assessing left ventricular function from gated SPECT perfusion studies. Rev Port Cardiol 2000; (Suppl. 1): 131–137.

11.

Teresifska

Wisuk

Konceczna

. Verification of the left ventricular ejection from gated myocardial perfusion studies (GSPECT). Kardiol Pol 2005; 63: 465–475.

12.

Murano

Narita

Kurinhara

. Left ventricular function assessed by multigated blood pool single photon emission tomography with 99mTc. J Cardiol 1992; 22: 245–253.

13.

Quinones

Gaasch

Alexander

. Echocardiographic assessment of left ventricular function with special reference to normalized velocities. Circulation 1974; 50: 42–51.

14.

Rich

Sheikh

Gallastegui

. Determination of left ventricular ejection fraction by visual estimation during real-time two-dimensional echocardiography. Am Heart J 1982; 104: 603–606.

15.

Kim

. Gated blood pool SPECT for measurement of left ventricular volumes and left ventricular ejection fraction: comparison of 8 and 16 frame gated blood pool SPECT. Int J Cardiovasc Imaging 2005; 21: 261–266.

16.

Bhatt

Hendel

. The diagnostic and prognostic value of ECG-gated SPECT myocardial perfusion imaging. J Nucl Med 2004; 45: 912–921.

17.

Yang

Yam

Chen

. Assessment of left ventricular ejection fraction using low radiation dose computed tomography. J Nucl Cardiol 2016; 23: 414–421.

18.

Chandler

Brenner

Lautamaki

. Comparison of measures of left ventricular function from electrocardiography gated 82R6 PET with contract-enhanced CT ventriculography: a hybrid PET/CT analysis. J Nucl Med 2008; 29: 1645–1650.

19.

McCullough

Andy

Christoph

. Epidemiology and prognostic implications of contrast-induced nephropathy. Am J Cardiol 2006; 98: 5K–13K.

20.

Rihal

Stephen

Diane

. Incidence and prognostic importance of acute renal failure after percutaneous coronary intervention. Circulation 2002; 105: 2259–2264.

21.

Batholomew

Kishore

Srinivas

. Impact of nephropathy after percutaneous coronary intervention and a method for risk stratification. Am J Cardiol 2004; 93: 1515–1519.

22.

Gholamrezanezhad

Sahar

Armaghan

. A correlative study comparing current different methods of calculating left ventricular ejection fraction. Nucl Med Commun 2007; 28: 41–48.

23.

Habash-Beselso

Rokey

Berger

. Accuarcy of non-invasive ejection fraction measurement in a large community-based clinic. Clin Med Res 2005; 3: 75–82.

24.

Barrett

Jacobs

Gomberg

. Simultaneous contrast imaging of the left ventricle by two-dimensional echocardiography and standard ventriculography. Clin Cardiol 1982; 5: 208–213.

25.

Poorzand

Abdolahi

Sajadian

. Left ventricular volume and function assessment: a comparison study between echocardiography and ventriculography. Arch Cardiovasc Imaging 2014; 2: e20737.

26.

Darbar

Gillespie

Choy

AMJ

. Diagnosing left ventricular dysfunction after myocardial infarction. The Dundee algorithm. Q J Med 1997; 90: 677–683.

27.

Hoffman

Von Bardeleben

ten Cate

. Assessment of systolic left ventricular functions: a multicenter comparison of ventriculography, cardiac magnetic resonance imaging, unenhanced and contrast echocardiography. Eur Heart J 2005; 26: 607–616.

28.

Albrechtsson

Eskilsson

Lomsky

. Comparison of left ventricular ejection fraction assessed by radionuclide angiography, echocardiography and contrast angiocardiography. Acta Med Scand 1982; 211: 147–152.

29.

Joffe

Ferrara

Chalian

. Are ejection fraction measurements by echocardiography and left ventriculography equivalent? Am Heart J 2009; 158: 496–502.

30.

Murarka

Attaran

Movahed

. Correlation between estimated ejection fraction measured by echocardiography with ejection fraction estimated by cardiac catheterization in patients awaiting cardiac transplantation. J Invas Cardiol 2010; 22: 571–573.

31.

Folland

Parisi

Moynihan

. Assessment of left ventricular ejection fraction and volumes by real time, two-dimensional echocardiography: a comparison of cineangiography and radionuclide techniques. Circulation 1979; 60: 760–766.

32.

Gula

Klein

Hellkamp

. For the SCD-HeFT investigators. Ejection fraction assessment and survival: an analysis of the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT). Am Heart J 2008; 156: 1196–1200.

33.

Mashiro

Kinoshita

Tomonaga

. Comparison of measurements of left ventricle by echography and cineangiography. Jpn Circ J 1975; 39: 23–35.

34.

Erbel

Schweizer

Lambertz

. Echoventriculography-a simultaneous analysis of two dimensional echocardiography and cineventriculogrpahy. Circulation 1983; 67: 205–215.

35.

Antani

Wayne

Kuzman

. Ejection phase indexes by invasive and noninvasive methods: an apexcardiographic, echocardiographic and ventriculographic correlative study. Am J Cardiol 1979; 43: 239–247.

36.

Abe

Kazatani

Fukuda

. Left ventricular volumes, ejection fraction and regional wall motion with gated technetium-99m tetrofosmin SPECT in reperfused acute myocardial infarction at super acute phase: comparison with left ventriculography. J Nucl Cardiol 2000; 7: 569–574.

37.

Yoshioka

Hasegawa

Yamaguchi

. Left ventricular volumes and ejection fraction calculated from quantitative electrocardiographic-gated 99m Tc-tetrofosmin myocardial SPECT. J Nucl Med 1999; 40: 1693–1698.

38.

Nichols

Tamis

Depuey

. Relation of gated SPECT ventricular function parameters to angiographic measurements. J Nucl Cardiol 1998; 295–303.

39.

Kondo

Fukashima

Kusakabe

. Measurement of left ventricular volumes and ejection fraction by quantitative gated SPECT, contrast ventriculography and magnetic resonance imaging. Eur J Nucl Med Mol Imaging 2003; 30: 851–858.

40.

Firouzabady

Bitarafan-Rajabi

Rastgoun

. Measurement of LVEF using ECG-grated SPECT and angiography: a correlation study. Iranian Heart J 2007; 8: 6–15.

41.

Godkar

Kalyan

Bijal

. Comparison and co-relation of invasive and noninvasive methods of ejection fraction measurement. J Natl Med Assoc 2007; 99: 1227–1234.

42.

Omar

Mohamed

Reda

. Comparison between gated SPECT and echocardiography in evaluation of left ventricular ejection fraction. J Egypt Nat Cancer Inst 2000; 12: 301–306.

43.

Berk

Isgoren

Demir

. Assessment of left ventricular function and volumes for patients with dilated cardiomyopathy using gated myocardial perfusion SPECT and comparison with echocardiography. Nucl Med Commun 2006; 26: 701–710.

44.

Mistry

Halvorsen

Hoffman

. Assessment of left ventricular function with magnetic resonance imaging vs. echocardiography, contrast echocardiography, and single photon emission computed tomography in patients with recent ST-evaluation myocardial infarction. Eur J Echocardiogr 2010; 160: 73–79.

45.

Cwaig

Zao-Xiang

. Gated myocardial perfusion tomography for the assessment of left ventricular function and volumes: comparison with echocardiography. J Nucl Med 1999; 40: 1857–1865.

46.

Mohan

Livieratas

Gallagher

. Comparison of myocardial gated single photon emission computerized tomography planar radionuclide ventriculography and echocardiography in evaluating left ventricular ejection fraction, wall-thickening and wall motion. Int J Clin Pract 2004; 58: 1120–1126.

47.

Chang

Chu

Chen

. Left ventricular ejection fraction measured from 99 Tc-Sestarmibi bi-myocardial perfusion gated SPECT: comparison with echocardiography. Ann Nucl Med 2010; 23: 11–18.

48.

Galasko

GIW

Basu

Lahiri

. Is echocardiography a valid tool to screen for left ventricular systolic dysfunction in chronic survivors of acute myocardial infarction? A comparison with radionuclide ventriculography. Heart 2004; 90: 1422–1426.

49.

Danesh-Sani

Zakavi

Oskoueian

. Comparison between 99mTc-sestamibi gated myocardial perfusion SPECT and echocardiography in assessment of left ventricular volumes and ejection fraction-effect of perfusion defect and small heart. Nucl Med Rev Cent East Eur 2014; 17: 70–74.

50.

Hatipoglu

Burak

Omur

. Comparison of gated myocardial perfusion SPECT, echocardiography and equilibrium radionuclide ventriculography in the evaluation of left ventricular contractility. Turk Kardiyol Dern Ars 2014; 42: 349–357.

51.

Nousiainen

Vanninen

Jantanen

. Comparison of echocardiography and radionuclide ventriculography in the follow-up of left ventricular systolic function in adult lymphoma patients during doxorubicin therapy. J Intern Med 2001; 249: 297–303.

52.

Darasz

Underwood

Bayliss

. Measurement of left ventricular volume after anterior myocardial infarction comparison of magnetic resonance imaging, echocardiography, and radionuclide ventriculography. Am Heart J 2009; 158: 496–502.

53.

Wright

Thacknay

Howey

. Left ventricular ejection fraction and volumes from gated blood pool SPECT: comparison with planar gated blood pool imaging and assessment of repeatability in patients with heart failure. J Nucl Med 2003; 44: 492–498.

54.

Bellenger

Burgess

Ray

. Comparison of left ventricular ejection fraction and volumes in heart failure by echocardiography, radionuclide ventriculography and cardiovascular magnetic resonance; are they interchangeable? Eur Heart J 2000; 21: 1387–1396.

55.

Castell-Conesa

Aguade-Braula

Garcia-Burillo

. Reproducibility of measurements of left ventricular function with gated myocardial perfusion SPECT and comparison blood pool radionuclide ventriculography. Rev Esp Cardiol 2004; 57: 931–938.

56.

Raja

Mittal

Santhosh

. Comparison of LVEF assessed by 2D echocardiography, gated blood pool SPECT, 99mTc tetrofosmin gated SPECT and 18F-FDG gated PET with ERNV in patients with CAD and severe LV dysfunction. Nucl Med Commun 2014; 35: 1156–1161.

57.

Sarwar

Shapiro

Nasir

. Evaluating global and regional left ventricular function in patients with reperfused acute myocardial infarction by 64-slice multidetector CT: a comparison to magnetic resonance imaging. J Cardiovasc Comput Tomogr 2009; 3: 170–177.

58.

Kim

Park

. Assessment of left ventricular ejection fraction and regional wall motion with 65-slice multidetector CT: a comparison with two-dimensional transthoracic echocardiography. Br J Radiol 2010; 8: 3328–3334.

59.

Sandler

Dodge

. The use of single plane angiocardiograms for calculation of left ventricular volumes in man. Am Heart J 1968; 75: 325–334.

60.

Schiller

Shah

Crawford

. Recommendations for quantitation of the left ventricle by two-dimensional echocardiography. J Am Soc Echocardiogr 1989; 2: 358–367.

Comparison of left ventricular ejection fraction values obtained using invasive contrast left ventriculography,two-dimensional echocardiography,and gated single-photon emission computed tomography