The world-famous medication used to improve erectile function – Viagra or sildenafil – can greatly suppress the manifestations of abnormal heart activity, according to a new study from the University of Manchester. The study, funded by the British Heart Foundation and published this week in Circulation Research, could significantly improve therapy for patients with this problem. In animal models, the drug was able to suppress a type of arrhythmia known as Torsades de Pointes within just 90 seconds. Sildenafil also reduces the likelihood of sudden cardiac death, a direct consequence of developing Torsades de Pointes arrhythmia. However, according to the team, the drug can have a positive effect on other types of arrhythmias as well. Cardiac arrhythmias are often a consequence of the development of a myocardial infarction or are the result of another heart disease. Although often benign, they can cause symptoms including palpitations, shortness of breath, loss of consciousness and even sudden death. Current treatments include beta-blockers and implantable defibrillators, but they are not always effective. Also working on isolated heart muscle cells, the research team was also able to measure their calcium stores – as well as their electrical properties. Although calcium is a key driver of the heart’s pumping function, excess calcium can be a major cause of arrhythmias. Viagra suppresses the mechanism in the cell that leads to calcium overload. In the presence of heart disease, the mechanisms regulating the entry of calcium may be ineffective, resulting in an irregular rhythm. Dr David Hutchings, a lecturer at the University of Manchester and lead author explains that the study not only demonstrates that sildenafil has a powerful antiarrhythmic effect on living heart tissue, but also reveals the cellular mechanisms by which this occurs. Although the study is based on results in animal models, the scientists believe that the discovery will also be relevant in the treatment of arrhythmia in humans. It has been suggested that the PDE5 enzyme, which is inhibited by sildenafil, may also play a key role in influencing heart rhythms that arise from calcium overload. Sources: https://medicalxpress.com/news/2021-09-sex-drug-strongly-suppress-abnormal.html https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.121.318473