title: Electromechanical mapping for detecting myocardial viability and ischemia in patients with severe ischemic cardiomyopathy.
abstract: This study was designed to evaluate several electromechanical mapping parameters for assessment of myocardial viability and inducible ischemia as defined by dipyridamole single-photon emission computed tomographic (SPECT) imaging at rest in patients with severe ischemic cardiomyopathy. Unipolar voltage, normalized unipolar voltage, bipolar voltage, and fragmentation were compared with tracer uptake at rest and reversibility on stress or rest quantitative technetium-99m sestamibi SPECT imaging in 32 patients with severe ischemic cardiomyopathy (left ventricular ejection fraction 0.24 +/- 0.08). In dysfunctional myocardial segments, logistic regression showed unipolar voltage, normalized unipolar voltage, and bipolar voltage to be predictive of viable myocardium (> or = 60% tracer uptake at rest) and was significantly higher in viable than in nonviable segments (p <0.01). A unipolar voltage of > or = 7.1 mV was the best predictor of viable myocardium. In dysfunctional viable segments, unipolar voltage was significantly higher in reversible than in fixed segments (p <0.001), and a unipolar voltage of > or = 8.5 mV had optimal power for identifying reversibility on dipyridamole SPECT imaging. We conclude that in patients with severe ischemic cardiomyopathy, unipolar voltage can identify viable from nonviable myocardium and reversible from fixed viable defects as defined by dipyridamole technetium-99m sestamibi SPECT imaging.
authors.affiliation: Cardiovascular Division, Department of Medicine, University of Virginia Health System, Charlottesville 22908-0158, USA. hsamady@virginia.edu
authors.forename: Habib
authors.initials: H
authors.lastname: Samady
authors.forename: Yi-Hwa
authors.initials: YH
authors.lastname: Liu
authors.forename: C Joon
authors.initials: CJ
authors.lastname: Choi
authors.forename: Michael
authors.initials: M
authors.lastname: Ragosta
authors.forename: Steven E
authors.initials: SE
authors.lastname: Pfau
authors.forename: Michael W
authors.initials: MW
authors.lastname: Cleman
authors.forename: Eric R
authors.initials: ER
authors.lastname: Powers
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Kramer
authors.forename: Frans J Th
authors.initials: FJ
authors.lastname: Wackers
authors.forename: George A
authors.initials: GA
authors.lastname: Beller
authors.forename: Denny D
authors.initials: DD
authors.lastname: Watson
mesh_terms: D000368:Aged; D018780:Body Surface Potential Mapping / Q000379:methods*; D009202:Cardiomyopathies / Q000175:diagnosis* / Q000503:physiopathology; D002470:Cell Survival / Q000502:physiology; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000503:physiopathology; D009206:Myocardium / Q000166:cytology / Q000473:pathology*; D011237:Predictive Value of Tests; D012372:ROC Curve; D019275:Radiopharmaceuticals; D012146:Rest / Q000502:physiology; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013312:Stress, Physiological / Q000503:physiopathology; D013318:Stroke Volume / Q000502:physiology; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000503:physiopathology
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi