Viagra significantly reduces stress on the heart

According to the results of a new study by researchers at Johns Hopkins, Viagra, a drug used to treat Erectile dysfunction (ED) in millions of men, reduces the stimulatory effects of hormonal stress on the heart by half.

The drug sildenafil, (Viagra), which is more widely known for helping genital blood vessels expand to maintain an erection and, recently, as a treatment for pulmonary hypertension, has previously been thought to have little direct effect on the human heart.

According to the study's senior author and cardiologist David Kass, M.D., a professor at The Johns Hopkins University School of Medicine and its Heart Institute, sildenafil blunts the strengthened heart beat caused by chemically induced stress, thereby lessening the excess amount of blood and force used to pump it to the body.

Kass says that in effect the drug puts a 'brake' on chemical stimulation of the heart.

The findings are believed to be the first confirmation in humans that sildenafil has a direct effect on the heart.

In previous research by Kass and his team it was shown that sildenafil had such effects in mice, blocking the short-term effects of hormonal stress in the heart.

Related studies by the group also showed that sildenafil prevents and reverses the long-term effects in the heart from chronic High Blood Pressure.

Kass says the latest results confirm that sildenafil helps control heart function only when the heart is under duress, but has little impact under normal conditions.

In separate research by Kass and his team earlier this year it was seen in mice that sildenafil could reverse the negative effects on heart muscle weakened by heart failure and enlargement, a condition called hypertrophy.

But at that time the team had no firm evidence as to whether or how this therapy might work in the human heart.

Their latest research provides firm evidence that the drug does have an important impact on the heart.

In the study 35 healthy men and women, with an average age of 30 and no previous signs of coronary artery disease, participated in a six-month study.

Within a three-hour timeframe, each participant received two separate injections of dobutamine , a synthetic, adrenaline-like chemical that increases heart rate and pumping strength.

Between injections, study participants were randomly assigned to a group that was treated with or to a group given a sugar pill placebo.