Exercise vs propranolol for postural orthostatic tachycardia syndrome
Postural orthostatic tachycardia syndrome (aka POTS, postural tachycardia syndrome) occurs when an abnormal increase in heart rate accompanies going from lying down to an upright position.
Researchers in the US evaluated exercise training vs beta-blockadewithpropranolol (Inderal) treatment in POTS patients.
First, the details.
- 19 patients with POTS were assigned to a treatment group.
- Propranolol for 4 weeks, followed by 3 months of exercise training
- Placebofor 4 weeks, followed by 3 months of exercise training
- 15 healthy individuals servedas a control group.
- A 2-hour standing test was performed before andafter drug treatment and training.
- Hemodynamics, catecholamines,plasma renin activity, and aldosterone were measured while lying downand during 2 hours of standing.
- Quality of life wasassessed using the 36-item Short-Form Health Survey.
- Neither the patients nor researchers knew the treatment given — double blind.
And, the results.
- Both propranolol andexercisetraining significantly lowered heart rate while standing.
- Standingcardiac output was significantly lowered after propranolol but minimally changed after training.
- The aldosterone:reninratio (determines blood pressure) during 2-hour standing remained unchanged after propranolol; yet it modestly, but significantly, increased after training.
- Blood levels of catecholamines were notaffected by propranolol or training.
- Patient quality of life significantly improvedafter training but not after propranolol.
The bottom line?
The authors concluded, “Forpatients with POTS, exercise training is superior to propranololat restoring upright hemodynamics, normalizing renal-adrenalresponsiveness, and improving quality of life.
Some patients with POTS are unable to attend school or work; and especially severe cases can completely incapacitate the patient.
More information on POTS from the National Institute of Neurological Disorders and Stroke can be found here.
7/5/11 22:48 JR
