Reduction of subendocardial myocardial blood flow (SE-MBF) is shown on the vertical axis and transmural myocardial blood flow (TM-MBF) on the horizontal axis. For 25% to 50% reduction of TM-MBF, the SE-MBF is reduced by 50% to 75%. Data from experimental studies were adapted and/or calculated from Gallagher et al. (16), Pantely et al. (17), Schulz et al. (18), and Fallavollita et al. (19), with permission.

Relationship of mean corrected myocardial blood flow (MBF), that is SE-MBF, to transmural grade of myocardial hyperenhancement (HE) before percutaneous coronary intervention (PCI) is shown (A). Comparison is made between segments subtended by stenosed and nonstenosed coronary arteries (p > 0.05 is not significant). In panel B, pre- and post-PCI data are shown in dark orange and light orange, respectively, for left ventricular end-diastolic (LVED) wall thickness, left ventricular (LV) wall thickening, left ventricular ejection fraction (LVEF), and corrected SE-MBF. Figure drawn from data of Selvanayagam et al. (24), with permission. Abbreviation as in Figure 1.

Late gadolinium-enhanced images are shown in a short-axis view (upper panels) and a long-axis view (lower panels) in 3 patients. Hyperenhancement is present (arrows) in various coronary-perfusion territories—the left anterior descending coronary artery, the left circumflex artery, and the right coronary artery—with a range of transmural involvement. Reprinted, with permission, from Kim et al. (41). LVD = left ventricular dysfunction; MRI = magnetic resonance imaging.

Short-axis ²⁰¹thallium tomograms during stress (top row), redistribution (middle row), and reinjection (bottom row) imaging in a patient with coronary artery disease. There are extensive ²⁰¹thallium abnormalities in the anterior and septal regions during stress that persist on redistribution images but improve markedly on reinjection images. Reprinted, with permission, from Dilsizian et al. (56).

Positron emission tomography (PET) scan showing perfusion (top) to metabolism (bottom) mismatch in hibernating heart as an example of preserved cardiometabolic reserve. Rubidium-82 PETs in short-axis view (top row) show markedly decreased perfusion defects in the apical, inferior, inferolateral, and septal regions of the left ventricle at rest, which extends from distal to basal slices. [¹⁸F] 2-deoxy-2-fluoroglucose images acquired under glucose-loaded condition (lower row) show perfusion-metabolism mismatch pattern (the scintigraphic hallmark of hibernation) in all abnormally perfused myocardial regions at rest, with the exception of the anteroseptal region, which demonstrates matched perfusion-metabolism pattern (compatible with scarred myocardium). Reprinted, with permission, from Taegtmeyer and Dilsizian (64).

Integration of resting data and new technologies predicts functional recovery in a patient with severe dysfunction (LVEF 25%). The resting study (A) shows no areas of thinning (1-cm markers in all walls) despite severe LV dysfunction and borderline restrictive filling (DT: 150 ms, E/A >2). Dobutamine stress shows basal inferior ischemia and mid inferior biphasic response in B. Peak-dose (40 µg/kg/min) dobutamine response showed hypokinetic septal and lateral walls had deteriorated at peak dose, which is consistent with extensive ischemia (C). CR = contractile reserve; DT = deceleration time; E/A = early-to-late diastolic filling ratio; HR = heart rate; other abbreviations as in Figure 2.

The data are derived from meta-analysis of 3,088 patients with coronary artery disease and left ventricular dysfunction who underwent viability testing. Death rates for patients with and without myocardial viability treated by revascularization or medical therapy are shown. In patients with viable myocardium, there is 79.6% reduction in mortality among those who were treated with revascularization (p < 0.0001). In contrast, among patients without evidence of viable myocardium, there was no significant difference in mortality with revascularization versus medical therapy. Adapted, with permission, from Allman et al. (7).

The relationship of reductions in death rate to resting left ventricular ejection fraction in patients who had revascularization. In patients with nonviable myocardium, there is no reduction of death with revascularization. In patients with viable myocardium, the lower the ejection fraction, the greater the reduction of deaths after revascularization. Reprinted, with permission, from Allman et al. (7). Abbreviations as in Figure 2.

Comparison of sensitivities and specificities (A) and predictive values (B) with 95% confidence intervals for the recovery of regional wall function. Comparison of sensitivities and specificities (C) and predictive values (D) of the various techniques with 95% confidence intervals for prediction of the recovery of global left ventricular function. Reprinted, with permission, from Schinkel et al. (86). FDG = ¹⁸F fluorodeoxyglucose; NPV = negative predictive value; PPV = positive predictive value; pts = number of patients; st = number of studies; Tc-99m = Technetium-99m–labeled agents; T1-201 = thallium 201; other abbreviations as in Figures 2, 3, and 5.

Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of data from various techniques with cardiac magnetic resonance (CMR). Figure developed from data of Schinkel et al. (86), with permission. ce-CMR = contrast-enhanced cardiac magnetic resonance; EDWT = end-diastolic wall thickness; other abbreviation as in Figure 3.

Sensitivity and specificity (A) and positive (PPV) and negative (NPV) (B) predictive value for predicting improvement in left ventricular function obtained by a direct comparison of dobutamine echocardiography (DE) and nuclear imaging (Nucl) of 325 patients in 11 studies. In each study, the same patients underwent both tests at the same medical center. Figure developed from data of Bax et al. (58), with permission.

Relationships between recovery of function after revascularization with contrast-enhanced cardiac magnetic resonance, and 2 thallium protocols optimized for viability detection: 1) rest-redistribution and 2) stress-redistribution-reinjection imaging are shown. Irrespective of the imaging modality applied, the data suggest that recovery of function after revascularization is a continuum and is coupled to the ratio of viable to scarred myocardium within dysfunctional myocardial segments. The extent of infarct size on CMR or percentage of thallium defect on SPECT correlated with decreasing likelihood of functional recovery after revascularization. Reprinted, with permission, from Dilsizian (88).