All of the tests listed are useful in assessing for viable myocardium, except for electron beam computed tomography. Rest-rest thallium, persantine sestamibi, and dobutamine echocardiography are relatively equivalent in sensitivity (approximately 80%). Fluorodeoxyglucose positron emission tomography, which identifies ischemic myocardium by its preferential metabolism of glucose rather than free fatty acids, is thought to be slightly more sensitive and specific in identifying viable myocardium. Recommendations regarding the optimal test depend on the expertise of the individual clinicians institution. Although the surgeons may be reassured by the presence of viable myocardium, because it is associated with better survival and lower perioperative mortality, thoughtful consideration must be paid to the individual patient, because no test is 100% predictive. Recent data reveal that even in the absence of traditionally defined evidence of viability, survival may be improved by revascularization in some patients. It is also becoming clear that assessing for viability to predict improvement in LV function and assessing to predict survival may not be the same. In a diabetic patient with multivessel CAD, coronary artery bypass grafting is the optimal revascularization procedure.
- Electron beam computed tomography.
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Seminars in Medical Practice
Hospital Physician Board Review Manuals
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