Voluntary exercise delays heart failure onset in rats with pulmonary artery hypertension
Professor White’s group’s observations on rats suggest that appropriate exercise regimes may be useful in the treatment of pulmonary artery hypertension.
Exercise guidelines exist for the management and treatment of patients with most cardiovascular diseases, but there has been reluctance to encourage pulmonary hypertensive patients to exercise because of the potential to increase mortality. The study used a rat model of voluntary wheel running to determine whether exercise training could be beneficial in the treatment of pulmonary artery hypertension and right ventricular failure. The authors found that, while wheel running did not prevent the development of the condition, in contrast to previous studies using enforced treadmill running, it did significantly delay the median time to heart failure.
Increased physical activity is recommended for the general population and for patients with many diseases because of its health benefits but can be contraindicated if it is thought to be a risk for serious cardiovascular events. One such condition is pulmonary artery hypertension (PAH). PAH and right ventricular failure was induced in rats by a single injection of monocrotaline (MCT). MCT rats with voluntary access to a running wheel ran on average 2 km/day. The time for half the animals to develop heart failure signs (median survival time) was 28 days (exercise failure group), significantly longer than sedentary animals (sedentary failure group, 23 days).
The contractility of single failing myocytes in response to increasing demand (stimulation frequency) was significantly impaired compared with that in both sedentary control and exercising control myocytes. However, myocytes from exercising MCT rats, tested at 23 days (exercise + MCT group), showed responses intermediate to the control (sedentary control and exercising control) and failing (sedentary failure and exercise failure) groups. We conclude that voluntary exercise is beneficial to rats with heart failure induced by PAH, and this is evidence to support the consideration of appropriate exercise regimes for potentially vulnerable groups.
The paper: Natali AJ; Fowler ED; Calaghan S; White E Voluntary exercise delays heart failure onset in rats with pulmonary artery hypertension. American journal of physiology. Heart and circulatory physiology ajpheart.00262.2015-ajpheart.00262.2015, 2015 – Editor’s pick Sept 2015
In this podcast Guest Editor Shawn Bender interviews lead author Ed White (University of Leeds) and content expert Daphne Merkus (Erasmus MC, Netherlands) about the work by Natali and co-authors: http://ajpheart.podbean.com/e/voluntary-exercise-in-heart-failure-rats/