title: Effects of posture on metabolic and hemodynamic predischarge exercise response after acute myocardial infarction.
abstract: Predischarge exercise testing after acute myocardial infarction (AMI) is an important noninvasive modality for risk stratification. To study the impact of position on cardiopulmonary exercise response, 30 patients performed symptom-limited upright treadmill and supine bicycle ergometry exercise an average of 8 days after an AMI. The exercise sequence was randomly assigned with a minimum 4-hour interval between tests. Exercise time and peak oxygen consumption were significantly greater in the upright position (7.0 +/- 2.0 vs 5.6 +/- 2.0 minutes; p less than 0.001 and 14.9 vs 12.0 ml/min/kg; p less than 0.001, respectively). Compared to the supine position, exercise in the upright position was associated with a significant increased incidence of ischemic exercise-induced ST-segment depression (33 vs 20%; p less than 0.03), and chest pain (20 vs 10%; p less than 0.04). Thus, position is an important determinant of myocardial ischemic response and exercise tolerance in patients who perform symptom-limited exercise tests early after AMI.
authors.affiliation: Department of Internal Medicine, St. Louis University School of Medicine, Missouri 63110-0250.
authors.forename: L J
authors.initials: LJ
authors.lastname: Shaw
authors.forename: L T
authors.initials: LT
authors.lastname: Younis
authors.forename: K S
authors.initials: KS
authors.lastname: Stocke
authors.forename: A K
authors.initials: AK
authors.lastname: Sharma
authors.forename: B R
authors.initials: BR
authors.lastname: Chaitman
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000502:physiology; D017023:Coronary Angiography; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D010101:Oxygen Consumption; D011187:Posture / Q000502:physiology*; D011659:Pulmonary Gas Exchange; D013990:Tidal Volume
chemical_list: D002245:Carbon Dioxide