Your heart's rhythm is controlled by electrical signals that allow the different parts of your heart to contract at the same time. These signals can be modified, in part, by chemicals, including adenosine. Adenosine can keep the heart from contracting, which is also known as asystole, and is sometimes used during cardiac medical procedures.
Adenosine Identification
Adenosine is a nucleoside, Drugs.com explains, which occurs naturally throughout the body. Nucleosides are chemicals which are used in the body to make DNA and RNA and they also play an important role as a chemical signal. Nucleosides such as adenosine can bind to special proteins, known as receptors, on the outside of cells. When adenosine binds to its receptors, it can change what is happening inside of the cell. One organ that responds to adenosine is the heart.
Adenosine Effects on Heart
Adenosine works by disrupting the electrical activity of a portion of the heart known as the A-V node. The A-V node is part of the heart which controls and initiates the electrical signals, which causes the heart to beat. Sometimes, these electrical signals get disrupted, resulting in arrythmias. Injecting a patient with adenosine essentially resets the heart by transiently blocking some of the electrical signals and allowing the heart to get back to its normal rhythm.
Adenosine and Asystole
Asystole is a condition in which the heart stops beating, the North Carolina Office of Emergency Medical Services notes. Asystole is sometimes caused by the administration of adenosine, Drugs.com notes. This asystole can be fatal but it can also be an intentional effect of adenosine administration. For example, temporary asystole can be used to temporarily stop the heart during cardiac ablation, a 2009 article in the journal "Europace" explains. Temporarily stopping the heart can be useful when doctors are taking images of the heart or performing delicate procedures.
Risks
As with any medication that affects the heart, there are risks associated with adenosine use. Although adenosine typically wears off quickly, it can stop the heart or induce other potentially fatal arrythmias. This seems to be more common in patients who are taking digoxin or verapamil, two medications often prescribed for heart problems. Adenosine's effects can also be blocked by caffeine, forcing doctors to use higher doses, Drugs.com reports.
