NEW YORK (Reuters Health) - Swimming and other water activities appear to be generally safe for many patients with severe but stable chronic heart failure, according to a report published in the journal Heart this month.

Heart failure patients "should not be forbidden to do sports activities in water," Dr. Jean-Paul Schmid from University Hospital, Bern, Switzerland, told Reuters Health.

Chronic heart failure or CHF is a condition in which the heart loses its ability to pump blood efficiently. The disease causes fatigue and shortness of breath as fluid accumulates in the lungs and tissues. It's generally recommended that heart failure patients avoid swimming as it may overtax their heart.

Schmid's team evaluated how 10 patients with stable CHF tolerated water activities and compared the results with those in 10 patients with coronary artery disease (CAD) and preserved heart pumping action and in 10 healthy controls.

Overall, the results indicate that heart failure patients with a reasonably high oxygen capacity "can safely do water sports," Schmid said. "This is also supported by a lot of reports of CHF patients that they tolerate exercise in water pretty well."

It's important to note, the investigators say that these results were obtained in water at a fairly neutral temperature. Patients should be informed that "warm water can lower blood pressure, which is in general already very low in CHF patients and that swimming can be quite strenuous," Schmid advised.

"Therefore, patients who want to swim in warm water should be cautious the first time. If they tolerate it well, there is no reason to bar them from water activities."