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Patients

Cardima’s mission is to provide the medical community with safe and innovative methods to diagnose and treat cardiac arrhythmias, giving patients the best treatment options.

What is Atrial Fibrillation?

The most common condition that disrupts the normal rhythm of the heartbeat is called atrial fibrillation (AF) and it affects over 2 million people in the United States annually. According to the American Heart Association and Heart Rhythm Society “about 160,000 new cases of AF are diagnosed each year.”

There are a number of risk factors that may predispose someone to develop AF including high blood pressure, heart failure, coronary artery disease, heart attack, heart valve disease, thyroid disease, lung disease, and age. However, in some people no apparent underlying cause can be found. Between 3% and 5% of the population over the age of 65 and approximately 9% of people over 80 will have AF.

When properly diagnosed and treated, AF is not generally life-threatening. Nevertheless, AF can increase the risk for stroke, heart failure or damage to other areas of the heart muscle. Once the underlying cause, nature and severity of AF is determined, you and your physician can decide what the most effective and appropriate treatment options are for your individual case. If it goes undiagnosed or untreated, AF can have a negative impact and limit one’s quality of life.

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The Heart’s Electrical System

The heart is divided into four chambers: the upper two chambers are the atria, and the lower two are the ventricles.

Atrial Fibrillation is a cardiac rhythm disorder characterized by a fast, irregular heartbeat. The electrical impulses that start in the 2 upper chambers of the heart (atria) are chaotic and erratic.

The heart is an electro-mechanical pump. The pumping action of the heart relies on its electrical system to contract the heart muscle cells and pump blood throughout the body. The right side of the heart receives unoxygenated (venous) blood from the body and then delivers it to the lungs to be oxygenated. The left side of the heart receives oxygenated (arterial) blood from the lungs and pumps it out to the rest of the body. The rhythmic contractions require electrical signals to reach each chamber in an organized, controlled manner.

The normal electrical heart beat starts in the right atrium within a specialized group of cells called the Sino-Atrial (SA) node. The SA node is the heart's "natural pacemaker," regularly discharging an electrical signal that, under normal circumstances, is responsible for setting the heart rate. The normal heart rate ranges from 60 to 100 beats per minute.

The signal that arises in the SA node spreads throughout the atria until it reaches the Atrio-Ventricular (AV) node. After the atria contract and fill the ventricles with blood, the signal travels down the Bundle of His (pronounced "hiss").

The electrical signal is then distributed widely throughout both ventricles by the Purkinje Fibers. The ventricles contract at the same time. Since the ventricles pump blood to the lungs and to the entire body, they are composed of a larger amount of muscle tissue than the atria. In the normal heart, the four chambers work in rhythm with each other. The heart's conduction system must function properly to make the heart an effective pump.

When this conduction system is functioning properly, it is known as normal sinus rhythm. If the electrical signals are transmitted through the heart cells in an erratic, uncontrolled manner, AF can result.

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What are the Signs and Symptoms of Atrial Fibrillation?

  • Rapid heart beat
  • Palpitations
  • Chest pain
  • Dizziness, fainting
  • Shortness of breath
  • Weakness and difficulty exercising
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What are the risks associated with atrial fibrillation?

  • Stroke
  • Blood clots in the heart that may travel to other areas of the body
  • Weaker function (pumping) of the left ventricle
  • Uncontrolled ventricular rate leading to enlargement of the heart and/or congestive heart failure
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How is Atrial Fibrillation Diagnosed?

Electrocardiogram (EKG or ECG)
Small electrodes are placed on the skin to identify and record the electrical impulses of the heart. However, electrocardiograms are not always able to determine the origin of the AF.
Holter Monitor
A small portable device that is able to detect and record irregular heart rhythms, much like an EKG. A patient is able to carry on with their normal routine activities while wearing the device, usually for a 24 - 48 hour period.
Exercise EKG
The EKG is done while the patient is exercising either on a bicycle or treadmill. The activity may produce arrhythmias (irregular cardiac rhythms) that were not present during a routine, resting EKG.
Electrophysiology (EP) Study
This is a diagnostic test to study the heart’s electrical system and pinpoint the specific location(s) causing the abnormal rhythm. The EP study involves placing catheters with electrodes inside the chambers of the heart. (The catheters are inserted into blood vessels in the groin, arm, or neck either through a small incision, or by means of a needle-stick and are advanced to the heart.) The electrodes record the electrical signals being generated and identify the precise areas responsible for the arrhythmia.
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What are the Treatments for Atrial Fibrillation?

Current treatments for AF are primarily supportive and palliative, meaning they only treat the symptoms rather than offer a cure. The main goals are to (1) reestablish a normal heartbeat and (2) prevent a stroke from occurring.

Medications

Medications that slow the heart rate – these help to slow the heart rate but will not stop the fibrillation.

Antiarrhythmics – These are aimed at restoring the heart's normal rhythm. Some of most commonly used antiarrhythmic drugs include quinidine, procainamide, flecainide, disopyramide, propafenone, amiodarone, and sotalol. These drugs often become less effective over time, with approximately half of the patients eventually developing resistance to the medications. In addition, these drugs can have some serious side effects, including pulmonary fibrosis and impaired liver function.

Anticoagulants or “blood thinners” -  These drugs limit the blood’s ability to clot in an effort to prevent a stroke. Common anticoagulants are Coumadin, warfarin and aspirin. You will have to have regular blood tests to monitor the degree of blood thinning.

External Cardioversion

The application of strong electrical current under general anesthesia aimed at “shocking” the heart back into a normal rhythm. This treatment is usually effective only for a limited period of time.

Pacemakers

Usually inserted in a Cardiac Catheterization Lab. Pacemakers control the heart rate, but do not treat the underlying disease process.

Internal Cardioverters / Defibrillators

Implanted devices that are programmed to automatically deliver a shock to the heart in instances of life-threatening arrhythmias. They also do not offer a cure or improve the quality of life for someone who suffers from AF.

Cox Surgical MAZE

This procedure is highly invasive requiring open heart surgery. However, it is a clinically proven cure for AF and has a success rate of over 90%.

The surgeon makes several incisions through the wall of the atrium with a scalpel, then cuts and sews the tissue back together to create a scar pattern. The scars isolate and block the erratic electrical impulses and the abnormal rhythm is controlled.

Surgical Ablation

A therapeutic procedure that is usually done when open-heart surgery is necessary for some other reason (for example, when a valve replacement is needed.) With newer technology, the procedure can now be performed alone, though small “holes” in the chest. The ablation portion consists of using an energy source to create lesions, or scar tissue, at certain points in the upper chambers of the heart (atria).

These lesions block the irregular electrical impulses that cause AF and allow the heart’s normal conduction system to take over. The most common energy source used in ablation procedures is radiofrequency (RF) energy, although several other methods such as laser, microwave, ultrasound, and cryothermy (freezing) have been used.

Linear ablation

Is performed in the EP or Cardiac Lab in the hospital. The goal of linear ablation is the same as the Cox Surgical Maze and surgical ablation techniques. The same energy sources as surgical ablation are used.

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Online Resources for Patients

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