5. What tests should be ordered a diagnosis of atrial fibrillation is made?
The diagnosis of atrial fibrillation is typically made on physical examination and confirmed with an electrocardiogram, or ECG. Since an ECG is simply a “snapshot” of the heart, often this won’t capture the atrial fibrillation. A holter monitor is a 24-hour monitor that may also be prescribed to evaluate if the atrial fibrillation is intermittent or continuous. There are also monitors that can be placed for a week and even longer if needed to fully evaluate the duration of atrial fibrillation and the control of the rate. These monitors continuously record the heart’s electrical activity. Once the diagnosis is made, other tests need to be performed to evaluate for the etiology of the atrial fibrillation. An echocardiogram is an ultrasound of the heart muscle and the cardiac valves and can rule out a structural etiology or a valve abnormality as the underlying cause. Routine blood tests to evaluate the thyroid, rule out anemia and check the liver and kidneys are important. An evaluation for underlying coronary artery disease must also be pursued if there is no obvious cause. A chest X-ray can also be important in the workup of atrial fibrillation as it can evaluate for chronic lung disease or an underlying infection.
6. What are the complications if the atrial fibrillation is not diagnosed and treated correctly?
By itself, atrial fibrillation is usually not life threatening. However, if left untreated the side effects of atrial fibrillation can be life threatening. The two main complications of atrial fibrillation are stroke and the development of a cardiomyopathy or weakened heart.
The stroke risk is great because atrial fibrillation pumps blood less efficiently and as the blood moves slower, it is more likely to form clots. If the clot is pumped out of the heart, it can travel to the brain and lead to a stroke.
The other complication of atrial fibrillation is the development of a cardiomyopathy or a weakened heart. Without appropriate treatment, atrial fibrillation can cause a fast heart rate for a long period. This continuous fast heart rate can cause the heart muscle to weaken. To prevent one of these complications, treatment for atrial fibrillation includes one medication to either control the rate or rhythm and the other to prevent stroke.
7. How do you prevent stroke and what are the different anticoagulants that can be used?
Anticoagulant agents, like Warfarin (Coumadin), Dabigatran (Pradaxa), Apixaban (Eliquis), and Rivaroxaban (Xarelto), are the main anticoagulants used to prevent stroke. Coumadin has been around for many years but recently the newer anticoagulants have become more of the standard of care because they require no monitoring of levels, and the levels do not fluctuate with diet. Also, the dose is constant and does not need to be adjusted. Aspirin can be used in patients who have very low risk of a stroke as determined by certain risk scores. Patients can be risk stratified by certain criteria and the appropriate stroke prevention strategy should be discussed with your doctor.
8. What are the different drugs used to control the rate and rhythm with atrial fibrillation?
Rate control is an important part of the treatment of atrial fibrillation to prevent symptoms and complications. Beta blockers, like Metoprolol (Toprol XL), Atenolol, and Propranolol (Inderal), and calcium channel blockers, like Diltiazem (Cardizem) and Verapamil, are commonly used to slow down the heart rate. In addition, the drug digoxin can be added to either a calcium channel blocker or a beta blocker for better rate control. Beta blockers, calcium channel blockers and digoxin do not convert the rhythm but rather are the cornerstone of rate control.
Antiarrhythmic drugs, like Amiodarone and Dronedarone, are also an option in patients who continue to have symptoms, even when the rate of the atrial fibrillation is controlled. In these cases, it is important to maintain sinus rhythm and these drugs work to restore sinus rhythm.
9. What is an atrial fibrillation ablation and who is a good candidate for this procedure?
Catheter ablation is a minimally invasive procedure used to treat atrial fibrillation. Most often this is done when medications are ineffective for controlling symptoms. During this procedure, a catheter is inserted into a vein, typically in the groin, and travels up into the heart. This catheter is used to deliver high energy, locally delivered radiofrequency signals to “ablate” the heart tissue where the abnormal impulses are originating from. This forms a scar or multiple scars that form a barrier that prevents electrical impulses from crossing between the damaged heart tissue to the surrounding healthy tissue. This will stop the conduction of the arrhythmia. There are a few risks to catheter ablations that include mainly bleeding and infection. One of the greatest drawbacks of atrial fibrillation is the need to redo the procedure for recurrent atrial fibrillation. This can occur about 30 percent of the time. The largest success rate is in patients who are under the age of 80 and have a normal ejection fraction.
10. How can I prevent atrial fibrillation?
To prevent atrial fibrillation, the key is to modify risk factors and avoid known triggers.
1. Keep your weight in a normal range.
2. Control high blood pressure.
3. Avoid excessive amounts of alcohol and caffeine.
4. Eat a heart healthy diet that is low in salt, saturated fats and cholesterol.
5. Don’t smoke.
6. Get regular activity.
