These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Exercise haemodynamic effects of beta-blockade and intrinsic sympathomimetic activity.
    Author: Ades PA, Wolfel EE, Hiatt WR, Fee C, Rolfs R, Brammell HL, Horwitz LD.
    Journal: Eur J Clin Pharmacol; 1989; 36(1):5-10. PubMed ID: 2917588.
    Abstract:
    Beta-adrenergic blockade with intrinsic sympathomimetic activity (ISA) causes less depression of resting and submaximal heart rate (HR) than non-ISA beta-blockers. The effects of these drugs on exercise haemodynamics have not been well studied. We evaluated effects of pindolol, propranolol and placebo during rest and steady-state exercise on cardiac output, oxygen consumption, calf blood flow, HR and blood pressure in 18 healthy subjects. Pindolol 5 mg and propranolol 80 mg given twice daily, reduced maximal exercise HR by 50 and 52 beats.min-1 respectively, confirming similarity of beta 1-blockade. Resting cardiac output was unchanged in all three groups after one week of therapy. Cardiac output, measured during steady-state exercise decreased in the propranolol group (18.3 vs 15.6 l.min-1) with no significant changes in pindolol (15.7 vs 16.01.min-1) or placebo (18.6 vs 17.3 l.min-1). The rise in cardiac output, from rest to exercise, was similarly attenuated by propranolol but not by pindolol or placebo. Exercise stroke volume increased 12% on pindolol (123-140 cc) and decreased 7% on propranolol (143-133 cc). Neither drug had a detrimental effect on exercise calf blood flow compared to placebo. Thus, unlike propranolol, pindolol with ISA, maintains a normal cardiac output during submaximal exercise.
    [Abstract] [Full Text] [Related] [New Search]