What Can Trigger Atrial Fibrillation?

Mild symptoms of atrial fibrillation may include Irregular heartbeat (arrhythmia).

Atrial fibrillation (also called AF or A-fib) is an abnormal or irregular heartbeat (arrhythmia). In A-fib, the upper chambers of the heart (the atria) beat irregularly because the electrical signals that control the heart are not functioning properly. This results in blood not being moved out of the upper chambers as quickly as it should and blood clots can form. Blood clots increase the risk of stroke. 

Some people may have no symptoms of atrial fibrillation. 

Mild symptoms of atrial fibrillation may include:

• Irregular heartbeat (arrhythmia)
• Heart palpitations 
• Sensation of tightness, pain, or discomfort in the chest
• Feeling of the heart racing
• Lightheadedness
• Mild shortness of breath
• Mild fatigue, especially with exercise

Severe symptoms of atrial fibrillation may include:

• Difficulty breathing, both with and without exertion
• Fainting
• Chest pain (angina)
• Severe fatigue

Risk factors for developing atrial fibrillation include age and underlying heart disease. 

The most common heart conditions that can cause A-fib include:

• Heart disease due to chronic high blood pressure (hypertensive heart disease)
• Heart attack
• Heart failure 
• Heart valve diseases, such as mitral regurgitation or mitral stenosis 
• Complications from heart surgery and occasionally complications resulting from other types of surgery

Other risk factors for developing A-fib include:

• Alcohol binge drinking 
• Overactive thyroid gland (hyperthyroidism)
• Certain medications, including drugs that stimulate the heart such as theophylline
• Sleep apnea 
• Chronic lung diseases such as emphysema
• Obesity
• Diabetes 
• Chronic kidney disease (CKD)

Atrial fibrillation is usually diagnosed with an electrocardiogram (ECG or EKG), a test that measures the heart's electrical activity. 

In some cases, a longer-term ECG recording, such as a Holter or event recorder (devices are worn over a day or two that monitor heart activity) may be used. 

Tests that may be indicated to check for other problems include:

• Echocardiogram (ultrasound) to check for heart failure or heart valve problems
• Blood tests to screen for thyroid disorders
• Sleep studies to check for sleep apnea
• Lung function tests to look for underlying lung disease

Treatment for atrial fibrillation is aimed at controlling heart rhythm and rate, and ensuring blood doesn’t clot (anticoagulation) to prevent stroke. 

Treatment to control heart rhythm includes:

• Electrical cardioversion (usually a first-line treatment in young patients with symptoms)
• Antiarrhythmic medications such as flecainide (Tambocor), propafenone (Rythmol), dofetilide (Tikosyn), amiodarone (Cordarone, Nexterone), and sotalol (Betapace)
• Ablation (catheter based, surgical, or hybrid) using heat (radiofrequency ablation) or cold (cryoablation)
• Surgical procedures, including the "maze procedure" 

Treatment to control heart rate includes:

• Medications such as non-dihydropyridine calcium channel blockers, beta-blockers, digoxin (Lanoxin), and amiodarone (Cordarone, Nexterone)
• Placement of a permanent pacemaker (used when other rates and rhythm control alternatives have not been successful)

Anticoagulation treatments include:

• Aspirin 
• Intravenous (IV) heparin or low-molecular-weight heparin (LMWH) 
• Warfarin (Coumadin)
• Newer oral anticoagulants
• Direct thrombin inhibitor: Dabigatran (Pradaxa)
• Factor Xa inhibitors: rivaroxaban (Xarelto), apixaban (Eliquis), edoxaban (Savaysa)

A serious complication associated with atrial fibrillation is stroke, which can occur if a blood clot forms in the atrium or ventricle of the heart and a piece of the clot (an embolus) breaks off. The clot can enter the bloodstream and block a blood vessel in the neck or the brain. When this occurs in the brain it causes a stroke, which can lead to permanent brain damage. 

Blood clots can also travel to the eyes, kidneys, spine, or arteries in the arms and legs.

• If A-fib is treated promptly and well managed, patients can have a normal life expectancy. 
• Poorer outcomes may occur in patients with heart failure, intraventricular conduction delay on an electrocardiogram, and prior heart attack.