Strokes are a leading cause of death, responsible for nearly 130,000 fatalities in the United States each year, according the Center for Disease Control. However, up to 800,000 die from a combination of strokes and cardiovascular disease. While not everyone dies from having a stroke, it leaves others with serious disabilities. Over 3 million people in the US are estimated to have atrial fibrillation, or afib, making them five times more likely to have a stroke than other members of the population.
Afib is a type of heart arrhythmia. An arrhythmia occurs when the heart doesn’t beat correctly—including beats that are quicker or slower than normal and beats with an overall irregular pattern, known as a fibrillation. The heart is broken up into four main chambers: the two upper atria and the two lower ventricles. Blood flows from the body and lungs into the atria, and then is pumped into the ventricles through the mitral and tricuspid valves. These valves close once the chambers are full, so blood can’t be pushed back into the atria when the ventricles contract, sending the reoxygenated blood back into the body.
Afib in particular affects the atria, thus the term atrial fibrillation. While a normal heart receives steady electrical impulses to induce beating, a heart with afib gets a barrage of signals, causing it to quiver rather than beat steadily. According to the American Heart Association, instead of an average 70 beats a minute, hearts with afib beat more than 300 times a minute. Thus, the atria beat irregularly and too rapidly, making the heart feel like it is constantly running a marathon. It may be chronic or episodic and can cause dizziness, difficulty breathing, exhaustion, palpitations, and chest pain. However, symptoms are not always present, which means many people don’t even know they have afib.
Pooling blood means clotting blood. This is especially dangerous in the atria, because the blood that leaves these upper chambers of the heart are pumped all over the body, and that means any blood clot that forms in the atria are as well. When one of these clots goes to the brain, it can completely block one of the brain’s arteries, causing an embolic or cardioembolic stroke. The blocking clot means the brain doesn’t get the oxygen it needs to keep brain cells healthy, so they start dying off.
Afib Preventative Measures
Just because you have afib doesn’t mean you are going to have a stroke. Although the risk increases greatly with age, there are some very simple lifestyle changes that can help manage the condition. Smoking on its own is a leading cause of stroke, but when combined with afib, it’s even more dangerous. Cigarettes make the blood thicker, thus more likely to clot. Alcohol abuse, obesity, and high blood pressure are other serious risk factors, and often interrelated. In some cases, a doctor may prescribe a blood thinner or other treatment method to keep afib under control. Thyroid, kidney, and other heart diseases can be underlying causes of afib, which means treating those may get rid of afib, decrease the chance of having a stroke, and lead to an overall healthier, longer life.