What is the Relationship Between AFIB and Stroke?
Atrial fibrillation is a condition where the left atrium of the heart has an irregular beat. During atrial fibrillation, or AFB, the cardiac muscle actually quivers in an erratic way, which gives the condition its name. The complications of an untreated atrial fibrillation include pulmonary edema and cardiac arrest. Stroke is a major risk of AFB. Even a series of silent strokes, where the patient has no symptoms and the damage is only seen on a brain scan, can lead over time to symptoms of dementia.
Why AFB Can Lead to Stroke
The rapid beating of the cardiac muscle in AFB is weaker than normal, which causes the blood flow to slow down. This in turn can cause the blood to pool and possibly form clots. If the clot leaves the heart and travels to the brain, it can block an artery. This blocking results in a stroke.
Symptoms and Warning Signs
The warning signs of a stroke include headache, weakness, paralysis or numbness, visual disturbances or partial blindness. The person may also experience pain behind their eye or their pupils may be of unequal size.
People who suffer from AFB sometimes don’t have symptoms, and their AFB is only discovered through an electrocardiogram, or ECG. Other people feel a fluttering above their heart or chest pains. They may also feel tired or faint and have shortness of breath.
A variety of conditions can lead to AFB. Among them are obesity, arteriosclerosis of the coronary arteries, hyperthyroidism, high blood pressure, and lung disease. In some patients, the cause is unknown. The risk of AFB increases with stress, cardiac surgery, excessive use of drugs, including drugs to treat the thyroid, smoking, alcoholism and low levels of electrolytes.
Risk of Stroke in AFB Patient
The risk of stroke in an AFB patient is four to six times the normal rate, and the risk increases with age. If the patient lives to be 80 or older, there’s a one in four chance that if they have a stroke it will be the result of AFB.
An AFB-caused stroke needs to be treated right away with drugs that dissolve the blood clot. Treatment by blood thinners, or anticoagulants reduce the incidence of stroke by one half to two thirds. The doctors then prescribe medications that keep blood clots from forming. One drug that is given to a stroke patient right away is heparin. It is given by injection then followed up with oral medications.
One of the most prescribed oral medications is warfarin. Though warfarin is effective, it can thin out the blood too much and cause bleeds. Since certain foods, other medications and even vitamins can effect warfarin, the patient needs to be monitored closely. Newer anticoagulants are now available that pose less risk of bleeds and don’t need to be monitored as closely as warfarin.
Some people whose AFB is mild can be treated with aspirin. The aspirin is taken alone or with other drugs. Doctors also prescribe beta blockers and calcium channel blockers that slow down the patient’s heartbeat and drugs that treat arrhythmia. Patients are also treated with electrical cardioversion, which shocks the cardiac muscle back into a normal rhythm.