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In clinical decision making, myocardial viability is defined as myocardium in acute or chronic coronary artery disease and other conditions with contractile dysfunction but maintained metabolic and electrical function, having the potential to improve dysfunction upon revascularization or other therapy. Several pathophysiological conditions may coexist to explain this phenomenon. Cardiac imaging may allow identification of myocardial viability through different principles, with the purpose of prediction of therapeutic response and selection for treatment. This expert consensus document reviews current insight into the underlying pathophysiology and available methods for assessing viability. In particular the document reviews contemporary viability imaging techniques, including stress echocardiography, single photon emission computed tomography, positron emission tomography, cardiovascular magnetic resonance, and computed tomography and provides clinical recommendations for how to standardize these methods in terms of acquisition and interpretation. Finally, it presents clinical scenarios where viability assessment is clinically useful. [ABSTRACT FROM AUTHOR]

Myriad advances in all fields of cardiac imaging have stimulated and reflected new understanding of cardiac performance, myocardial damage and the mechanisms of heart failure. In this paper, the Heart Failure Association assesses the potential usefulness of innovative imaging modalities in enabling more precise diagnostic and prognostic evaluation, as well as in guiding treatment strategies. Many new methods have gradually penetrated clinical practice and are on their way to becoming a part of routine evaluation. This paper focuses on myocardial deformation and three-dimensional ultrasound imaging; stress tests for the evaluation of contractile and filling function; the progress of magnetic resonance techniques; molecular imaging and other sound innovations. The Heart Failure Association aims to highlight the ways in which paradigms have shifted in several areas of cardiac assessment. These include reassessing of the simplified concept of ejection fraction and implementation of the new parameters of cardiac performance applicable to all heart failure phenotypes; switching from two-dimensional to more accurate and reproducible three-dimensional ultrasound volumetric evaluation; greater tissue characterization via recently developed magnetic resonance modalities; moving from assessing cardiac function and congestion at rest to assessing it during stress; from invasive to novel non-invasive hybrid techniques depicting coronary anatomy and myocardial perfusion; as well as from morphometry to the imaging of pathophysiologic processes such as inflammation and apoptosis. This position paper examines the specific benefits of imaging innovations for practitioners dealing with heart failure aetiology, risk stratification and monitoring, and, in addition, for scientists involved in the development of future research. [ABSTRACT FROM AUTHOR]

Objectives: Dobutamine stress echocardiography (DSE) and contrast-enhanced electron beam tomography (EBCT) both have the potential to noninvasively detect coronary artery disease (CAD). We compared the accuracy of both methods to detect significant CAD in a direct comparison. Methods: 79 patients (32 women, 47 men, mean age 62 years) who were admitted for coronary angiography due to suspected CAD were studied. By EBCT coronary calcification (CAC) as well as angiography (CTA) was assessed. Presence of significant CAD was assumed if the calcium score exceeded 400 or the contrast-enhanced images displayed significant lumen reduction. DSE was performed using a standard protocol (5–40 μg/kg/min dobutamine plus 0.25–1.0 mg atropine if necessary). DSE and EBCT were independently evaluated concerning the presence of signficant CAD. Results were compared to invasive, quantitative coronary angiography. Results: 6 patients (8%) in DSE and 2 patients (3%) in EBCT were unevaluable for various reasons and therefore excluded from further analysis. In the remaining 71 patients, 33 patients (46%) showed significant CAD. DSE demonstrated a sensitivity of 70% (23/33) and a specificity of 84% (32/38). EBCT showed a sensitivity of 91% (30/33) and a specificity of 74% (28/38). By combining DSE and EBCT sensitivity increased to 97% with a specificity of 63%. Conclusions: In a blinded comparison, DSE demonstrated lower sensitivity but higher specificity than EBCT for the detection of significant CAD. Sensitivity was improved by combining both modalities. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: In myocardial contrast echocardiography (MCE), power modulation technique may quantify myocardial perfusion in real-time. However, constant infusion of the contrast agent (CA) complicates handling. This pilot study sought for the clinical feasibility of quantitative MCE by a CA bolus application during Adenosine stress echocardiography to diagnose coronary artery disease (CAD). Twenty-four consecutive patients (pts) with contemporary coronary angiography underwent rest and maximum Adenosine stress. Signal intensity could be calculated in 316/348 left ventricular (LV) segments (91%) (18-segment model). At rest, gamma-variate (alpha) as well as saturation function (beta) was not significantly different in healthy men (n = 268) as well as CAD pts (n = 48) (alpha: 0.34 s-1 versus 0.40 s−1, n.s.; beta: 0.31 s−1 versus 0.35 s−1, n.s.). During Adenosine infusion both values increased in healthy men (alpha: 0.34 ± 0.37 s−1 versus 0.44 ± 0.45 s−1, p < 0.05; beta: 0.31 ± 0.33 s−1 versus 0.40 ± 0.40 s−1, p < 0.01), but not in CAD (alpha: 0.40 ± 0.35 s−1 versus 0.29 ± 0.29 s−1, n.s.; beta: 0.35 ± 0.32 s−1 versus 0.27 ± 0.30 s−1, n.s.). Sensitivity of alpha/beta reserve ≤1 was 65%/67% (specificity 66%/67%) and improved to 88% in both if also wall motion analysis was considered (specificity 59%/65%). A very high negative predictive value of 96%/97% favours the method for excluding CAD. Bolus administration of CA is feasible in quantitative real-time MCE. However, additional consideration of wall motion analysis is required for reasonable sensitivity. Very high negative predictive values favour the potential of the method in excluding the diagnosis. Further need of research work may be encouraged by those findings. (E-mail: nixdorff@ecp-checkup.de) [Copyright &y& Elsevier]