New Study-Propranolol, Exercise And Pots

[firewatcher]

Neurology. 2013 Apr 24. [Epub ahead of print]

Low-dose propranolol and exercise capacity in postural tachycardia syndrome: A randomized study.

Arnold AC, Okamoto LE, Diedrich A, Paranjape SY, Raj SR, Biaggioni I, Gamboa A.

Source

From the Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University, Nashville, TN.

Abstract

OBJECTIVE:

To determine the effect of low-dose propranolol on maximal exercise capacity in patients with postural tachycardia syndrome (POTS).

METHODS:

We compared the effect of placebo vs a single low dose of propranolol (20 mg) on peak oxygen consumption (VO₂max), an established measure of exercise capacity, in 11 patients with POTS and 7 healthy subjects in a randomized, double-blind study. Subjects exercised on a semirecumbent bicycle, with increasing intervals of resistance to maximal effort.

RESULTS:

Maximal exercise capacity was similar between groups following placebo. Low-dose propranolol improved VO₂max in patients with POTS (24.5 ± 0.7 placebo vs 27.6 ± 1.0 mL/min/kg propranolol; p = 0.024), but not healthy subjects. The increase in VO₂max in POTS was associated with attenuated peak heart rate responses (142 ± 8 propranolol vs 165 ± 4 bpm placebo; p = 0.005) and improved stroke volume (81 ± 4 propranolol vs 67 ± 3 mL placebo; p = 0.013). In a separate cohort of POTS patients, neither high-dose propranolol (80 mg) nor metoprolol (100 mg) improved VO₂max, despite similar lowering of heart rate.

CONCLUSIONS:

These findings suggest that nonselective β-blockade with propranolol, when used at the low doses frequently used for treatment of POTS, may provide a modest beneficial effect to improve heart rate control and exercise capacity.

CLASSIFICATION OF EVIDENCE:

This study provides Class II evidence that a single low dose of propranolol (20 mg) as compared with placebo is useful in increasing maximum exercise capacity measured 1 hour after medication.

• PMID:
• 23616163
• [PubMed - as supplied by publisher]

[Chaos]

Really interesting article Firewatcher! Thanks for posting. My doc has switched me from propanalol to nadalol and have not been able to exercise like I used to ever since. Was blaming it on the relapse I had prior to the switch but now I wonder what part of it the med switch has played. Hmmmm.

[Enid]

I think, (not with a whole lot of confidence but enough to mention...) that nadalol is also a non selective beta blocker ...so not sure the switch from propanalol to nadalol would explain a lessened exercise capacity..

more hmm...

[ramakentesh]

Thanks - great article.