Atrial Fibrillation

alt text 
Atrial fibrillation is a disturbance of the normal, regular, clock-like rhythm of your heart caused by chaotic electrical impulses that interfere with the normal electrical conduction system of your heart. It manifests as an irregular, oftentimes rapid heart rate that can impair normal cardiac function. Usually, atrial fibrillation begins as intermittent episodes and progresses over time to a continuously irregular heartbeat. Its manifestations are varied, from being essentially without symptoms to profound fatigue. Atrial fibrillation is also associated with an increased incidence of stroke, as blood clots can form in the atria and make their way into the brain. To mitigate this risk, patients in atrial fibrillation are usually prescribed a blood thinner called Coumadin.

Our surgeons are well acquainted with operations designed to treat atrial fibrillation.

Causes of Atrial Fibrillation

It is generally believed that the upper chambers of the heart, known as the atria, possess focuses of aberrant electrical impulses that interfere with the normal electrical pathway that regulates your heart’s regular rhythm.

Risk Factors

There are several risk factors that may increase your likelihood of developing atrial fibrillation. These include:
  • Age: As age increases, so does the risk for developing atrial fibrillation.
  • Heart disease: Heart disease, including valve conditions, a prior heart attack, or heart surgery, are all risk factors.
  • Chronic medical conditions: Certain conditions, such as thyroid conditions and sleep apnea, can increase the risk of developing atrial fibrillation. 
  • Alcohol: Drinking alcohol has been known to trigger episodes of atrial fibrillation. 
  • Family history: Atrial fibrillation is known to run in families.

Symptoms

Atrial fibrillation is not always associated with symptoms. However, some common symptoms include:
  • Palpitations or a racing and irregular heartbeat
  • Low blood pressure
  • Feelings of weakness or lightheadedness
  • Shortness of breath (dyspnea)

Diagnostic Tests

There are several tests that are used to diagnose atrial fibrillation:

Electrocardiogram (ECG): An ECG measures your heart’s electrical impulses and is the primary test used to diagnose atrial fibrillation.

Holter monitoring: A Holter monitor is a portable device that records a continuous ECG designed to detect any heart rhythm irregularities over a period between 24 and 72 hours. The information gathered from the monitor is reviewed to check for any recorded irregularities over this time period. Holter monitoring is particularly useful when episodes of atrial fibrillation are intermittent and/or infrequent.

Event recorder: This is a device similar to the Holter monitor. There are two types of recorders used. One transmits signals when a symptom is occurring and one that is worn all the time. These recorders are usually worn for up to a month.

Echocardiogram: An echocardiogram uses sound waves to create a dynamic real-time image of the heart. This imaging is used to detect structural abnormalities that may be caused by atrial fibrillation and can detect blood clots resulting from this rhythm disturbance.

Blood tests: Blood tests are usually used to rule out thyroid problems or other metabolic causes of atrial fibrillation.

Chest x-ray: A chest X-ray may be used as a screening test to look for atrial chamber enlargement, which is a predisposing condition for developing atrial fibrillation.

Treatment

alt text 
There are two parts of medical treatment for atrial fibrillation. In general, medical treatment is used first before more more invasive procedures are considered. The first part of medical therapy involves the use of medications to suppress the occurrence of atrial fibrillation episodes. There are many different medications with different side-effects, but are generally safe when administered by a qualified physician. The second part entails the use of a blood-thinner called Coumadin which impairs your blood from clotting normally. This is necessary to prevent the formation of blood clots within the quivering chambers of your heart that can lead to stroke or other serious complications. 

In many cases, medical treatment for atrial fibrillation is ineffective or carries so many side effects as to be highly undesirable or unsafe for the patient. In this case, more aggressive treatment for atrial fibrillation involves destroying, or ablating those regions of the heart that create the extra electrical impulses responsible for atrial fibrillation. Ablation can be conducted with a catheter inserted into your heart through one of your leg vessels or with surgery. These two approaches have their own advantages and disadvantages which your doctors can discuss with you.

In surgical ablation, an energy source is used to burn or freeze regions of the heart that are known to create the extra electrical impulses that cause atrial fibrillation. These ablations can be performed through a standard breast-bone splitting incision or through smaller incisions through the ribs. The approach is often determined by whether there are other cardiac procedures that need to be performed at the same time (e.g., valve replacement, coronary artery bypass). In many cases, a small portion of the left atrium in which blood clots tend to form can be removed from the heart at the time of the ablation, thereby lowering the risk of stroke.

A radio-frequency energy device is applied to a portion of the left atrium to block aberrant electrical impulses that cause atrial fibrillation.