title: Effects of moderate exercise training on thallium uptake and contractile response to low-dose dobutamine of dysfunctional myocardium in patients with ischemic cardiomyopathy.
abstract: BACKGROUND
  There is evidence that exercise training can induce myocardial and coronary adaptations in both animals and humans. However, the significance of these potentially important changes remains to be determined in patients with ischemic heart disease and left ventricular (LV) systolic dysfunction.
  
  
  RESULTS
  To investigate whether exercise training can improve thallium uptake and the contractile response to low-dose dobutamine of dysfunctional myocardium, 46 patients (42 men, 4 women; mean age, 57+/-9 years) with chronic coronary artery disease and impaired LV systolic function (ejection fraction < 40%) were randomly assigned to two groups. The exercise group (n = 26) underwent exercise training at 60% of peak oxygen uptake for 8 weeks. The control group (n = 20) was not exercised. At baseline and after 8 weeks all patients underwent an exercise test with gas exchange analysis and stress echocardiography using low-dose dobutamine (5 to 10 microg/kg per minute) followed by thallium myocardial scintigraphy. Coronary angiography was performed in 23 patients at baseline and after 8 weeks. After 8 weeks, peak oxygen uptake increased significantly only in trained patients (24%). Significant improvements in the contractile response to dobutamine and thallium activity were observed in trained patients (28% and 31%, respectively; trained versus control: P<.001 for both). In a subgroup of trained patients, both improvements were correlated with an increase in the coronary collateral score (P<.005 and P<.001, respectively).
  
  
  CONCLUSIONS
  Moderate exercise training improves both thallium activity and the contractile response of dysfunctional myocardium to low doses of dobutamine in patients with ischemic cardiomyopathy. The implication of this study is that even a short-term exercise training may improve quality of life by improvement of LV systolic function during mild-to-moderate physical activity in patients with ischemic cardiomyopathy.
authors.affiliation: Divisione di Cardiologia I, Istituto Cardiologica G.M. Lancisi, Ancona, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Belardinelli
authors.forename: D
authors.initials: D
authors.lastname: Georgiou
authors.forename: L
authors.initials: L
authors.lastname: Ginzton
authors.forename: G
authors.initials: G
authors.lastname: Cianci
authors.forename: A
authors.initials: A
authors.lastname: Purcaro
mesh_terms: D000222:Adaptation, Physiological; D000318:Adrenergic beta-Agonists; D000368:Aged; D003097:Collateral Circulation; D004280:Dobutamine; D004452:Echocardiography; D005081:Exercise Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D011877:Radionuclide Imaging; D018709:Statistics, Nonparametric; D013794:Thallium Radioisotopes; D016277:Ventricular Function, Left
chemical_list: D000318:Adrenergic beta-Agonists; D013794:Thallium Radioisotopes; D004280:Dobutamine