NEW YORK (CNN/Money) - Scientists from Johns Hopkins University have discovered that Viagra, Pfizer's treatment for erectile dysfunction, could also be used to reduce stress that can lead to heart attacks.

In a placebo-controlled study at the university's Department of Medicine in Baltimore, scientists found that Viagra dampened the effect of artificially-induced stress to the heart, according to Dr. David Kass, the John Hopkins cardiology professor who directed the study.

"At the same time that [Pfizer] is enhancing erectile dysfunction, it's also blunting the stress that would be imposed by the act of sex," said Kass.

Participants in the study were injected with dobutamine, a drug that sped the heart rate "like stepping on the accelerator pedal," said Kass. Participants who took Viagra experienced less of an effect from the dobutamine, which was used to simulate physical or emotional stress.

Viagra, a blockbuster drug that totaled $1.7 billion in 2004 sales, works by increasing the flow of blood in the body, helping men with circulatory problems achieve erection.

"[Viagra] got started as a heart drug in the early 1990s and the erectile dysfunction [treatment] was a side effect," said Kass. "It got sidetracked for a completely different implication."

Kass hopes that his study will "open the door" for other functions for Viagra, also known as sildenafil.

To read about Pfizer's (up $0.11 to $21.20, Research) third quarter earnings, click here.