George A. Beller

Bio: George A. Beller is an academic researcher from University of Virginia Health System. The author has contributed to research in topics: Coronary artery disease & Myocardial perfusion imaging. The author has an hindex of 25, co-authored 78 publications receiving 5851 citations.

Myocardial infarction redefined - A consensus document of the Joint European Society of Cardiology/American College of Cardiology committee for the redefinition of myocardial infarction

Abstract: This document was developed by a consensus conference initiated by Kristian Thygesen, MD, and Joseph S. Alpert, MD, after formal approval by Lars Ryden, MD, President of the European Society of Cardiology (ESC), and Arthur Garson, MD, President of the American College of Cardiology (ACC). All of the participants were selected for their expertise in the field they represented, with approximately one-half of the participants selected from each organization. Participants were instructed to review the scientific evidence in their area of expertise and to attend the consensus conference with prepared remarks. The first draft of the document was prepared during the consensus conference itself. Sources of funding appear in Appendix A. The recommendations made in this document represent the attitudes and opinions of the participants at the time of the conference, and these recommendations were revised subsequently. The conclusions reached will undoubtedly need to be revised as new scientific evidence becomes available. This document has been reviewed by members of the ESC Committee for Scientific and Clinical Initiatives and by members of the Board of the ESC who approved the document on April 15, 2000.

Prediction of cardiac events after uncomplicated myocardial infarction: a prospective study comparing predischarge exercise thallium-201 scintigraphy and coronary angiography.

Abstract: The ability of predischarge quantitative exercise thallium-201 (201T1) scintigraphy to predict future cardiac events was evaluated prospectively in 140 consecutive patients with uncomplicated acute myocardial infarction; the results were compared with those of submaximal exercise treadmill testing and coronary angiography. High risk was assigned if scintigraphy detected 201T1 defects in more than one discrete vascular region, redistribution, or increased lung uptake, if exercise testing caused ST segment depression greater than or equal to 1 mm or angina or if angiography revealed multivessel disease. Low risk was designated if scintigraphy detected a single-region defect, no redistribution, or no increase in lung uptake, if exercise testing caused no ST segment depression or angina, or if angiography revealed single-vessel disease or no disease. By 15 +/- 12 months, 50 patients had experienced a cardiac event; seven died (five suddenly), nine suffered recurrent myocardial infarction, and 34 developed severe class III or IV angina pectoris. Compared with that of patients at low risk, the cumulative probability of a cardiac event was greater in high-risk patients identified by scintigraphy (p less than .001), exercise testing (p = .011), or angiography (p = .007). Scintigraphy predicted low-risk status better than exercise testing (p = .01) or angiography (p = .05). Each predicted mortality with equal accuracy. However, scintigraphy was more sensitive in detecting patients who experienced reinfarction or who developed class III or IV angina. When all 50 patients with events were combined, scintigraphy identified 47 high-risk patients (94%), whereas exercise-induced ST segment depression or angina detected only 28 (56%) (p less than .001). The presence of multivessel disease as assessed by angiography identified nine more patients with events than exercise testing (p = .06). However, the overall sensitivity of angiography was lower than that of scintigraphy (71% vs 94%; p less than .01) because three patients who experienced reinfarction and 10 who developed class III or IV angina had single-vessel disease. Importantly, 12 (92%) of these 13 patients with single-vessel disease who had an event exhibited redistribution on scintigraphy. These results indicate that (1) submaximal exercise 201T1 scintigraphy can distinguish high- and low-risk groups after uncomplicated acute myocardial infarction before hospital discharge; (2) 201T1 defects in more than one discrete vascular region, presence of delayed redistribution, or increased lung thallium uptake are more sensitive predictors of subsequent cardiac events than ST segment depression, angina, or extent of angiographic disease; and (3) low-risk patients are best identified by a single-region 201T1 defect without redistribution and no increased lung uptake.

Contributions of Nuclear Cardiology to Diagnosis and Prognosis of Patients With Coronary Artery Disease

Abstract: In the past decade, significant advances have been made in the ability to image the heart with radionuclide tracers under stress and resting conditions in patients with suspected or known coronary artery disease (CAD) for the detection of ischemia, determination of prognosis, assessment of myocardial viability, preoperative risk assessment for patients undergoing noncardiac surgery, and evaluation of the efficacy of revascularization in patients undergoing coronary artery bypass surgery or an interventional procedure.1 For many years, planar imaging and SPECT with 201Tl constituted the only scintigraphic techniques available for detecting CAD and assessing prognosis in patients undergoing stress perfusion imaging. The major limitation of 201Tl scintigraphy is the high false-positive rate observed in many laboratories, which is attributed predominantly to image attenuation artifacts and variants of normal that are interpreted as defects consequent to a significant coronary artery stenosis. Although quantification of 201Tl images improves specificity, the false-positive rate remains problematic, particularly in women and in obese patients. Breast attenuation artifacts in women are sometimes difficult to distinguish from perfusion abnormalities secondary to inducible ischemia or myocardial scar. In recent years, new 99mTc-labeled perfusion agents have been introduced into clinical practice to enhance the specificity of SPECT and to provide additional information regarding regional and global left ventricular systolic function via ECG gating of images. It was immediately apparent that the quality of images obtained with these new 99mTc-labeled radionuclides was superior to that of images obtained with 201Tl because of the more favorable physical characteristics of 99mTc imaging with a gamma camera. With 99mTc, doses of ≈10 to 20 times higher than those that are feasible with 201Tl can be administered, yielding images with higher count density. 99mTc demonstrates less scatter and attenuation than 201Tl, which is associated …

Noninvasive assessment of myocardial perfusion.

Abstract: Noninvasive assessment of myocardial perfusion is important in the diagnosis and risk stratification of patients with known or suspected coronary artery disease (CAD). Although single-photon emission computed tomography (SPECT) is most commonly used, multiple modalities including myocardial contrast echocardiography (MCE), positron emission tomography (PET), cardiac MRI (CMR), and cardiac computed tomography (CT) have emerged as promising techniques. This article will critically evaluate the strengths and weakness of these modalities for evaluating myocardial perfusion. Myocardial perfusion is a highly regulated process that includes epicardial vessels, resistance vessels, and the endothelium. Endothelial dysfunction is an early manifestation of vascular disease and plays a role in the development of CAD.1 In normal coronaries, sympathetic stimulation causes a flow-mediated endothelium-dependent release of nitric oxide resulting in epicardial and arteriolar vasodilation. With endothelial dysfunction, vasoconstriction from acetylcholine predominates, resulting an attenuation or absence of the normal flow-mediated vasodilation.2 When coronary arteries are narrowed by atherosclerotic disease, coronary autoregulation attempts to normalize myocardial blood flow by reducing the resistance of distal perfusion beds to preserve adequate myocardial oxygen supply.3 A stenosis must exceed 85% to 90% of luminal diameter before significant reductions in resting blood flow occur.4 However, under vasodilator stimulus, maximal coronary flow has been shown to decrease with stenosis of >45% (Figure 1).4 This has been demonstrated clinically using quantitative PET myocardial perfusion imaging (MPI).5,6 Because perfusion is an early change in the ischemic cascade,7 stress modalities that assess coronary perfusion reserve have a higher sensitivity in detecting flow-limiting stenoses than analysis of stress-induced wall motion abnormalities or ECG changes alone.8 Abnormal coronary flow reserve with vasodilator stress in the absence of a significant coronary stenosis occurs and has been attributed to microvascular and/or endothelial dysfunction.9 Figure 1. Relationship between percent diameter stenosis and …

2016 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure

Abstract: ACC/AHA : American College of Cardiology/American Heart Association ACCF/AHA : American College of Cardiology Foundation/American Heart Association ACE : angiotensin-converting enzyme ACEI : angiotensin-converting enzyme inhibitor ACS : acute coronary syndrome AF : atrial fibrillation

2016 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure

Abstract: ACC/AHA : American College of Cardiology/American Heart Association ACCF/AHA : American College of Cardiology Foundation/American Heart Association ACE : angiotensin-converting enzyme ACEI : angiotensin-converting enzyme inhibitor ACS : acute coronary syndrome AF : atrial fibrillation

Third universal definition of myocardial infarction

Abstract: ACCF : American College of Cardiology Foundation ACS : acute coronary syndrome AHA : American Heart Association CAD : coronary artery disease CABG : coronary artery bypass grafting CKMB : creatine kinase MB isoform cTn : cardiac troponin CT : computed tomography CV : coefficient of variation ECG : electrocardiogram ESC : European Society of Cardiology FDG : fluorodeoxyglucose h : hour(s) HF : heart failure LBBB : left bundle branch block LV : left ventricle LVH : left ventricular hypertrophy MI : myocardial infarction mIBG : meta-iodo-benzylguanidine min : minute(s) MONICA : Multinational MONItoring of trends and determinants in CArdiovascular disease) MPS : myocardial perfusion scintigraphy MRI : magnetic resonance imaging mV : millivolt(s) ng/L : nanogram(s) per litre Non-Q MI : non-Q wave myocardial infarction NSTEMI : non-ST-elevation myocardial infarction PCI : percutaneous coronary intervention PET : positron emission tomography pg/mL : pictogram(s) per millilitre Q wave MI : Q wave myocardial infarction RBBB : right bundle branch block sec : second(s) SPECT : single photon emission computed tomography STEMI : ST elevation myocardial infarction ST–T : ST-segment –T wave URL : upper reference limit WHF : World Heart Federation WHO : World Health Organization Myocardial infarction (MI) can be recognised by clinical features, including electrocardiographic (ECG) findings, elevated values of biochemical markers (biomarkers) of myocardial necrosis, and by imaging, or may be defined by pathology. It is a major cause of death and disability worldwide. MI may be the first manifestation of coronary artery disease (CAD) or it may occur, repeatedly, in patients with established disease. Information on MI rates can provide useful information regarding the burden of CAD within and across populations, especially if standardized data are collected in a manner that …

ESC Guidelines for the Diagnosis And Treatment of Acute And Chronic Heart Failure 2008

Abstract: Authors/Task Force Members: John J.V. McMurray (Chairperson) (UK)*, Stamatis Adamopoulos (Greece), Stefan D. Anker (Germany), Angelo Auricchio (Switzerland), Michael Böhm (Germany), Kenneth Dickstein (Norway), Volkmar Falk (Switzerland), Gerasimos Filippatos (Greece), Cândida Fonseca (Portugal), Miguel Angel Gomez-Sanchez (Spain), Tiny Jaarsma (Sweden), Lars Køber (Denmark), Gregory Y.H. Lip (UK), Aldo Pietro Maggioni (Italy), Alexander Parkhomenko (Ukraine), Burkert M. Pieske (Austria), Bogdan A. Popescu (Romania), Per K. Rønnevik (Norway), Frans H. Rutten (The Netherlands), Juerg Schwitter (Switzerland), Petar Seferovic (Serbia), Janina Stepinska (Poland), Pedro T. Trindade (Switzerland), Adriaan A. Voors (The Netherlands), Faiez Zannad (France), Andreas Zeiher (Germany).