Viagra, a medicine prescribed for erectile dysfunction, has been in discussion on a lot of forums regarding its safety in individuals suffering from heart diseases. Studies have been conducted to determine the effects of Viagra (sildanefil) on heart. Heart is a very complex structure that continuously pumps blood throughout the lifespan.

If there is volume overload on heart such as in high blood pressure, it will cause the heart to enlarge and finally it will stop pumping blood due to heart failure. This catastrophe is prevented by a gene that is RGS2 (regulator of G-protein signaling 2), which functions to protect the heart from going into failure. This is the gene that works to prevent heart from enlarging and keeping it fit to pump blood into the arterial tree.

In order to prove the role of Viagra (sildanefil citrate) in protecting heart from the deleterious effects of high blood pressure was demonstrated by subjecting the mice to high blood pressures. These mice were divided into two groups, one were those that did not have RGS2 and the other with the RGS2, protective gene for heart that prevents the heart from hypertrophy.

Both the groups were induced with high blood pressure and the mice that were lacking the gene RGS2 had about 90% increase in the weight of the heart and about half of the mice of this group died during the experiment. On the other hand the group of mice that had RGS2, there was seen a delay in the process of hypertrophy (muscle expansion) of the heart.

The experiments also revealed that mice that had RSG2 when given (Viagra) sildanefil citrate showed to have higher buffering, which resulted in very decreased amounts of hypertrophy as compared to the mice that had RSG2 but were not given Viagra. The study also revealed that the mice that did not have RSG2 gene had no effect of sildanefil on heart.

The experiments to study the effects of RSG2 to prevent heart’s enlargement have been going on for about three years now and now more recent experiments are focused to determine the combined effects of sildanefil and RSG2 on preventing heart from enlarging.

Another important factor that is linked to heart failure is due to Gq signaling, which performs the function of vasoconstriction and controls the vascular smooth muscle. The establishment of the fact through these researches about the RSG2 genes in the heart that prevents its hypertrophy, the scientists can now develop better therapies by including ARB or sildanefil to prevent people from going into heart failure.

Currently the doctors use ARB inhibitor and the ACE inhibitor to block the Gq signals, as these medicines block the effects of Gq signals by allowing them to relax and breaks the constrictive effects that causes the increased blood pressure.

There have been other researches going on to determine the role of sildanefil (Viagra) to better the arterial pressure in lungs by blocking the PDE5, which is phosphodiesterase 5 that functions by constricting the blood vessels. The individuals suffering from pulmonary hypertension were seen to get good results by using sildanefil as a mode of treatment.

The researchers mentioned that pulmonary hypertension affects the right ventricle of the heart and that results in hypertrophy of heart muscles. They found that the phosphodiesterase 5 is expressed in the heart muscles of the right ventricle and sildanefil works to block that and also improve the performance of the muscles in the right ventricle, in the hypertrophied heart.

Thus sildanefil not only prevents pulmonary hypertension but also improves the pumping ability of the right heart that pumps the blood into the left atrium from where the blood is pumped into the left ventricle and then into the arterial tree.