Viagra against heart failure: Researchers throw light on the mechanism

Viagra against heart failure: Researchers throw light on the mechanism: Sildenafil, the active ingredient in Viagra, can alleviate heart problems, and now researchers can explain why. They studied dogs with diastolic heart failure, a condition in which the heart chamber does not sufficiently fill with blood. The scientists showed that sildenafil makes stiffened cardiac walls more elastic again. The drug activates an enzyme that causes the giant protein titin in the myocardial cells to relax.