Table 1

 Characteristics of dysfunctional but viable myocardium

CharacteristicTechniqueSigns of viability
FDG, F18-fluorodeoxyglucose; MRI, magnetic resonance imaging; SPECT, single photon emission computed tomography.
Contractile reserveDobutamine echocardiography, dobutamine MRIImproved contraction during infusion of low dose dobutamine
Intact cell membraneThallium-201 SPECTTracer activity >50%
Redistribution (>10%)
Intact mitochondriaTechnetium-99 m SPECTTracer activity >50%
Improved tracer uptake after nitrates
Glucose metabolismFDG imagingTracer activity >50%
Preserved perfusion/FDG uptake
Perfusion–metabolism mismatch