Atrial Fibrillation

Introduction

Atrial Fibrillation, also known as A Fib or AF, is a common heart condition that causes an abnormal rhythm (arrhythmia). It is sometimes described as a quivering heart or fluttering heartbeat. A change in the electrical charge that travels through the heart’s upper chambers can cause the rhythm of the heart to get out of sync. During an episode, typical symptoms include heart palpitations, shortness of breath, and weakness that may come and go or last for extended periods of time. A Fib is a treatable condition that should be managed by a cardiologist to prevent serious complications, such as blood clots, heart failure, or stroke. AF is not life-threatening, but emergency treatment may be required at times to restore regular rhythm.

Anatomy

The heart is an organ whose primary function is to pump blood throughout the body. It is divided into four sections called chambers, with two on top and two on bottom. Blood comes in through the upper chambers (atria) and exists through the lower chambers (ventricles). There are four valves that regulate the flow of blood through the heart. The lub-dub sound your heart makes with each beat is the sound of heart values opening and closing. The pumping action of the heart is controlled by electrical impulses from the sinus node, which starts each heartbeat in a steady rhythm.

When the heart receives irregular electrical impulses, the rhythm becomes irregular. It will start beating irregularly in an attempt to correct and restore the natural rhythm. In the case of A Fib, the AV node, which connects the upper chambers to the lower chambers, is flooded with electrical impulses. This causes the bottom of the heart to beat more rapidly than the top, and the rhythm falls out of sync.

Causes

The cause of atrial fibrillation is an abnormality in the heart. In some cases a heart defect you are born with or cardiovascular disease of some kind can be the cause. A history of heart attack, high blood pressure, hyperthyroidism, and alcohol abuse can increase your risk. Lung disease, pneumonia, and previous heart surgery are other possible causes.

People with an otherwise healthy heart and no other risk factors can also have atrial fibrillation. The arrhythmia is caused by “hot spots” on the heart that act like abnormal pacemaker cells. They fire rapid electrical impulses, causing the upper chambers of the heart to flutter or quiver instead of beating normally.

Symptoms

Someone with atrial fibrillation may have no symptoms at all, making it difficult to detect and diagnose. During an episode, the classic symptom is a fast, irregular heartbeat, often described as a fluttering or quivering feeling in your chest. This is usually accompanied by shortness of breath, weakness, and fatigue (extreme tiredness). You may also experience dizziness, sweating, lightheadedness, anxiety, and chest pain.

Diagnosis

Some people may never know they have A Fib until their doctor examines their heart. Normally, your heart beats steadily without you noticing it at all. If you suddenly notice your heartbeat, it may be due to a change in the electrical impulses that regulate the rhythm. Be sure to consult your doctor right away. Take note of how long and how often you notice your own heart beat and what it feels like.

Lab tests and cardiac imaging are used to confirm the diagnosis. Common tests used to diagnose AF include a blood work (to eliminate other possible causes), chest x-ray, electrocardiogram (ECG), and echocardiogram. You may need to wear a Holter or Event monitor to detect an arrhythmic event during a 24 to 48-hour period.

Treatment

The type of treatment you need will depend on the frequency and severity of your symptoms. Most commonly, symptoms will last for less than a week, which can be managed relatively easily. But for some, the symptoms will last indefinitely, which requires a different treatment approach. The overall goal of treatment is the same – restore your natural rhythm and prevent complications, like blood clots.

There are two ways to reset the rhythm using a cardioversion. An electrical shock can be delivered to your chest to shock the heart back into sync, or special medication can be administered while your condition is monitored to see if your heart will reset on its own.

After getting the heart beat back on track, your doctor may prescribe certain medications to address the cause of A Fib. Normal treatment includes an anticoagulant (blood thinner) to prevent blood clots and reduce the risk of stroke. Anti-arrhythmia medication may also be prescribed to help regulate your heart beat and prevent future episodes. A combination of drugs may be needed to control heart rate, as well.

For some cases of A Fib, surgical intervention may be needed to repair diseased or damaged areas in the heart that restrict blood flow. A stent or pacemaker may be inserted during the repair. Or, a special technique can be used to create scar tissue on the heart to redirect electrical impulses because electricity cannot travel across scar tissue. This can be accomplished with a catheter ablation or surgical maze procedure. The scars are made using radiofrequency, cryotherapy, or heat. A catheter ablation can correct arrhythmias without the need for medication or an implantable device. Ablation of the AV node may be an option if a catheter ablation doesn’t work. A surgical maze procedure requires open heart surgery, which is not recommended unless all other options have failed.

Prevention

Preventing atrial fibrillation is usually handled with anti-arrhythmia medication and simple changes in lifestyle, like swapping coffee for caffeine-free tea. Even with medication, you are still at risk for stroke, heart failure, and other serious complications if you have had atrial fibrillation. If there is an underlying condition, such as hyperthyroidism causing your symptoms, treating the thyroid can prevent or reduce A Fib.

If you know that you are at risk for A Fib because of heart disease or certain risk factors, the best thing to do is avoid substances that can be stimulating, like alcohol, tobacco, caffeine, and some medications. You should also eat heart-healthy foods, get appropriate exercise, maintain a healthy weight, avoid stress, and of course, see your doctor regularly for check-ups to keep symptoms at bay.

Am I at Risk

Because atrial fibrillation is usually associated with cardiac abnormalities, having heart disease can increase your risk. Other risk factors include a family history of A Fib, obesity, alcohol abuse, high blood pressure, and some chronic conditions like sleep apnea, diabetes, hyperthyroid, and lung disease.