title: Myocardial viability assessment by endocardial electroanatomic mapping: comparison with metabolic imaging and functional recovery after coronary revascularization.
abstract: OBJECTIVE
  The objective of this study was to compare electroanatomic mapping for the assessment of myocardial viability with nuclear metabolic imaging using positron emission computed tomography (PET) and with data on functional recovery after successful myocardial revascularization.
  
  
  BACKGROUND
  Animal experiments and first clinical studies suggested that electroanatomic endocardial mapping identifies the presence and absence of myocardial viability.
  
  
  METHODS
  Forty-six patients with prior (> or =2 weeks) myocardial infarction underwent fluorine-18 fluorodeoxyglucose (FDG) PET and Tc-99m sestamibi single-photon emission computed tomography (SPECT) before mapping and percutaneous coronary revascularization. The left ventricular endocardium was mapped and divided into 12 regions, which were assigned to corresponding nuclear regions. Functional recovery using the centerline method was assessed in 25 patients with a follow-up angiography.
  
  
  RESULTS
  Regional unipolar electrogram amplitude was 11.0 mV +/- 3.6 mV in regions with normal perfusion, 9.0 mV +/- 2.8 mV in regions with reduced perfusion and preserved FDG-uptake and 6.5 mV +/- 2.6 mV in scar regions (p < 0.001 for all comparisons). At a threshold amplitude of 7.5 mV, the sensitivity and specificity for detecting viable (by PET/SPECT) myocardium were 77% and 75%, respectively. In infarct areas with electrogram amplitudes >7.5 mV, improvement of regional wall motion (RWM) from -2.4 SD/chord +/- 1.0 SD/chord to -1.5 SD/chord +/- 1.1 SD/chord (p < 0.01) was observed, whereas, in infarct areas with amplitudes <7.5 mV, RWM remained unchanged at follow-up (-2.3 SD/chord +/- 0.7 SD/chord to -2.4 SD/chord +/- 0.7 SD/chord).
  
  
  CONCLUSIONS
  These data suggest that the regional unipolar electrogram amplitude is a marker for myocardial viability and that electroanatomic mapping can be used for viability assessment in the catheterization laboratory.
authors.affiliation: Medizinische Klinik I, Department of Cardiology, Aachen, Germany.
authors.forename: K C
authors.initials: KC
authors.lastname: Koch
authors.forename: J
authors.initials: J
authors.lastname: vom Dahl
authors.forename: M
authors.initials: M
authors.lastname: Wenderdel
authors.forename: B
authors.initials: B
authors.lastname: Nowak
authors.forename: W M
authors.initials: WM
authors.lastname: Schaefer
authors.forename: A
authors.initials: A
authors.lastname: Sasse
authors.forename: C
authors.initials: C
authors.lastname: Stellbrink
authors.forename: U
authors.initials: U
authors.lastname: Buell
authors.forename: P
authors.initials: P
authors.lastname: Hanrath
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D022062:Electrophysiologic Techniques, Cardiac; D004699:Endocardium / Q000502:physiology*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D009206:Myocardium / Q000378:metabolism; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D017256:Technetium Tc 99m Sestamibi; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon; D016276:Ventricular Function
chemical_list: D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi