ATRIAL FIBRILLATION

Atrial fibrillation (commonly referred to as AFib) is the most common type of heart arrhythmia, or abnormal heartbeat. Normally, the sinoatrial or sinus (SA) node regulates the electrical impulses that cause the heart’s atria (upper chambers) to contract and force blood into the ventricles (lower chambers). The SA node also causes the ventricles to contract and pump blood out of the heart and to the rest of the body.

With atrial fibrillation, a number of electrical impulses fire at one time, causing a fast and chaotic heart rhythm. This rhythm prevents the atria from properly contracting and forcing blood into the ventricles. It also causes the ventricles to improperly contract, resulting in a rapid, irregular heartbeat. 

Causes of Atrial Fibrillation

Atrial fibrillation is often caused by underlying heart disease, which might include:

  • Cardiomyopathy
  • Congenital heart defects
  • Coronary artery disease
  • Heart failure
  • Heart valve defects
  • Hypertension (high blood pressure)
  • Pericarditis
  • Pulmonary embolism

Many individuals also begin experiencing atrial fibrillation following heart surgery. Some other potential causes of this condition include:

  • Chronic lung disease
  • Hyperthyroidism
  • Viral infections
  • Electrolyte or metabolic imbalances
  • Obesity
  • Diabetes
  • Obstructive sleep apnea
  • Excessive use of alcohol or caffeine
  • Use of certain drugs
  • Stress
  • Genetic factors
  • High-dose steroid therapy

In some cases, there’s no apparent cause of atrial fibrillation.

Symptoms of Atrial Fibrillation

Atrial fibrillation can cause someone to experience:

  • Heart palpitations
  • Chest pain or discomfort
  • Shortness of breath
  • Fatigue
  • Weakness
  • Dizziness
  • Fainting
  • Confusion
  • Swelling within the legs, ankles and feet

It’s important to remember that some individuals can have atrial fibrillation without experiencing any resulting symptoms.

Diagnosing Atrial Fibrillation

A physician will perform a physical examination and may order an electrocardiogram (EKG) to confirm or rule out a diagnosis of atrial fibrillation. If symptoms are intermittent, a patient may be directed to wear a special event monitor for a certain amount of time. Additionally, blood tests, echocardiograms and sleep studies can all be useful when determining how to approach treatment.

Treatment for Atrial Fibrillation

It’s important to promptly treat atrial fibrillation. If left untreated, this condition can increase the risk of stroke and heart failure and cause damage to other areas of the body. Treatment is aimed at controlling the heart rate, regaining a normal heart rhythm, preventing the formation of blood clots and lowering the risk of stroke.

Physicians at Tampa General Hospital’s Heart and Vascular Institute often recommend that patients first make certain lifestyle changes, such as:

  • Maintaining a healthy weight
  • Limiting alcohol and caffeine consumption
  • Quitting smoking
  • Avoiding certain activities


Treatment may also require electrical cardioversion, medication and, in some cases, surgery.