NEW YORK (Reuters Health) – The results of a recent study suggest that a lengthened set of single leg-press exercises at a moderate lifting intensity is safe in heart transplant recipients.
In a report in the November issue of the International Journal of Cardiology, Dr. Neil McCartney, of McMaster University, Hamilton, Ontario, Canada, and colleagues describe the cardiovascular responses of heart transplant recipients to a single, prolonged bout of weight lifting training.
The researchers stratified 23 patients into one of three post-transplantation groups, including early (3 months; n = 6), intermediate (1 to 3 years; n = 7) or late (5 to 14 years; n = 10). Dr. McCartney's group examined four experimental conditions, including "supine rest, upright rest, single leg-press exercise (28 repetitions over 2 minutes 20 seconds at 50%), and recovery."
"Swan-Ganz catheterization allowed measurement of right heart pressures and cardiac output by thermodilution," the investigators explain. "Systemic arterial pressures and heart rate were measured continuously using a non-invasive finger cuff."
Cardiac output in the early, intermediate, and late groups increased by 30%, 40%, and 54%, respectively, according to the report. Similarly, heart rate increased by 4.8%, 10.5%, and 16% in the early, intermediate, and late groups, respectively.
At peak exercise, systolic blood pressure reached a mean of 179 mm Hg (15% increase) in the early group (p < 0.001). In the intermediate and late groups, systolic blood pressure reached a mean of 180 mm Hg (27% increase) and 176 mm Hg (28% increase), respectively (p < 0.001).
"Average mean pulmonary artery pressure did not exceed 30 mm Hg and average pulmonary wedge pressure did not exceed 15 mm Hg in any group during the exercise," the investigators report.
"To better address the specific rehabilitation needs of heart transplant recipients, future research should focus on developing training programs which include weight lifting exercise," Dr. McCartney and colleagues conclude.
Int J Cardiol 2001;81:61-74.