title: Detection of myocardial ischemia by transesophageal echocardiographically determined changes in left ventricular area in patients undergoing coronary artery bypass surgery.
abstract: OBJECTIVE
  To evaluate left ventricular (LV) dimensions and function during myocardial ischemic episodes in anesthetized patients undergoing coronary artery bypass surgery.
  
  
  METHODS
  Prospective, nonrandomized study.
  
  
  METHODS
  Large, medical school-affiliated tertiary-care medical center.
  
  
  METHODS
  36 adults undergoing elective primary coronary artery bypass surgery.
  
  
  METHODS
  Transesophageal atrial pacing for 3 to 5 minutes at heart rates (HRs) of 65, 70, 80, and 90 beats per minute.
  
  
  RESULTS
  Arterial, pulmonary artery, and venous pressures, transesophageal echocardiographic (TEE) determined LV end-diastolic (EDA) and end-systolic (ESA) areas, and fractional area change (FAC = [FDA-ESA]/EDA). Myocardial ischemia determined as at least 1 mm ST segment deviation at J + 60 milliseconds from 12-lead electrocardiography (ECG) and TEE detected new LV regional wall motion abnormalities. Biplane TEE images were recorded on videotape, and LV EDA and ESA were determined with planimetry from images of the LV short axis. Myocardial ischemia was observed in 12 patients. In these patients, EDA and ESA were higher and FAC lower than those patients without ischemia at the same HR. There were no differences between patients with and without myocardial ischemia with regard to pulmonary artery occlusion pressure, stroke volume, or other hemodynamic variables. The positive predictive values were best for ESA (67%) and EDA (58%), and least for FAC (18%). Negative predictive values were highest for ESA (85%) and EDA (80%), and least for FAC (47%).
  
  
  CONCLUSIONS
  In anesthetized patients undergoing coronary artery bypass surgery, myocardial ischemia observed during atrial pacing results in increases in LV dimensions and decreases in FAC compared with values in patients without ischemia. These results support further investigations of the clinical usefulness of monitoring LV EDA and LV ESA with TEE as a method of myocardial ischemia detection.
authors.affiliation: Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Hogue
authors.forename: V G
authors.initials: VG
authors.lastname: Dávila-Román
mesh_terms: D000368:Aged; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D017548:Echocardiography, Transesophageal; D006801:Humans; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology; D011446:Prospective Studies; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*