title: Effect of timolol on cardiopulmonary exercise performance in men after myocardial infarction.
abstract: The effect of the nonselective beta blocker timolol on maximal cardiopulmonary exercise performance was evaluated in 28 men with previous myocardial infarction without effort angina (mean age 63 +/- 8 years). Patients were randomized to placebo or timolol (10 mg twice daily) for 4 weeks and then crossed over to the alternative therapy in a double-blind manner. At the completion of each treatment period, patients underwent symptom-limited maximal cardiopulmonary exercise on a cycle ergometer. Exercise time, heart rate, oxygen consumption (VO2), oxygen (O2) pulse and respiratory exchange ratio were measured at peak exercise and at a submaximal exercise level defined at a respiratory exchange ratio of 1.00. Timolol treatment reduced peak heart rate from 153 +/- 11 to 102 +/- 14 beats/min (-33%, p less than 0.001). Exercise time decreased from 680 +/- 91 to 633 +/- 78 seconds (-7%, p less than 0.001). Peak VO2 decreased from 25.3 +/- 4.7 to 21.4 +/- 3.5 ml/min/kg (-15%, p less than 0.001). O2 pulse increased from 12.9 +/- 1.9 to 16.7 +/- 2.3 ml/beat (+29%, p less than 0.001). Peak respiratory exchange ratio did not change significantly, indicating comparable effort. At submaximal exercise, defined at a respiratory exchange ratio of 1.00, there was no difference in exercise time between placebo and timolol. Heart rate decreased with timolol compared with placebo, from 126 +/- 16 beats/min by 31% (p less than 0.001), VO2 decreased from 18.5 +/- 4.3 ml/min/kg by 10% (p less than 0.001), O2 pulse increased from 11.5 +/- 2.0 ml/beat by 30% (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Cardiology Division, Central Hospital nn Rogaland, Stavanger, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Barvik
authors.forename: K
authors.initials: K
authors.lastname: Dickstein
authors.forename: T
authors.initials: T
authors.lastname: Aarsland
authors.forename: H
authors.initials: H
authors.lastname: Vik-Mo
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000503:physiopathology / Q000517:prevention & control*; D004311:Double-Blind Method; D005080:Exercise Test / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000187:drug effects; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D013999:Timolol / Q000627:therapeutic use*
chemical_list: D013999:Timolol