Coronary artery spasms are a bit of a medical mystery.
Occurring in approximately 0.0004 percent of the population, coronary artery spasms are less common than blood clots [source: MedLine Plus]. They're usually not fatal. As with blood clots, coronary artery spasms, also called variant angina, are usually related to coronary artery disease. But sometimes they happen to people with no apparent heart problems at all.
A coronary artery spasm is pretty straightforward: It occurs when a part of the arterial heart muscle contracts suddenly, or squeezes shut. You can think of it in terms of any other type of muscle spasm, like when your bicep muscle tenses up out of nowhere. It's usually quite painful, and it doesn't last very long.
Unlike a sudden contraction in an arm muscle, though, a contraction in your heart muscle can have very serious results very quickly. A coronary artery spasm might last anywhere from five to 30 minutes, and it can cause chest pain [source: MedLine Plus]. Chest pain is usually called angina. Variant angina is different in that it usually occurs at rest (often when a person is asleep) instead of during a period of high exertion, and it may not be connected with heart disease. In some instances, maybe one-third of cases, people with no major heart-attack risk factors can have a coronary artery spasm [source: ClevelandClinic]. If it lasts, say, five minutes, the damage is minimal, limited to chest pain (or possibly no symptoms at all). It's usually treated with pharmaceuticals like beta-blockers, calcium-channel blockers or nitroglycerin.
If it lasts for, say, 30 minutes, the results can be dire. If the contracted artery muscle cuts off blood flow to the heart for an extended period of time, a heart attack can result.
Medical science is still not sure why variant angina occurs in otherwise healthy people. It may have something to do with a dysfunction in the endothelium cells that line blood vessels. Doctors do know what can increase the risk, though. Aside from heart disease, using drugs like cocaine, tobacco and amphetamine can lead to coronary spasm, as can severe stress and alcohol withdrawal.
Variant angina is a chronic condition and needs to be treated long-term. With use of the proper drugs when chest pain first occurs, a heart attack becomes far less likely.
For more information on variant angina, blood clots and other heart-related conditions, look over the links on the next page.