catheter ablation


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Catheter Ablation

 

Definition

Catheter ablation of an irregular heartbeat involves having a tube (a catheter) inserted into the heart through which electrical energy is sent to either reset the heartbeat or stop the heart from beating so a mechanical pacemaker can be put in place.

Purpose

Irregular heartbeats can occur in healthy people without causing any dangerous symptoms or requiring medical attention. Slight changes in the normal patterns of heartbeats often reset themselves without notice.
But when the heartbeat is greatly disrupted—either because of traumatic injury, disease, hypertension, surgery, or reduced blood flow to the heart caused by blockages in the blood vessels that nourish the heart—the condition must be recognized and treated immediately. Otherwise, it can be fatal.
Various drugs can be used to control and help reset these abnormal heart rhythms (arrhythmias). The technique of catheter ablation (meaning tube-guided removal) is used to interrupt the abnormal contractions in the heart, allowing normal heart beating to resume. Atrial fibrillation and flutter and Wolff-Parkinson-White syndrome are two of the most common disorders treated with catheter ablation.

Precautions

The improper correction of abnormal heartbeats can cause additional arrhythmias and can be fatal. Abnormalities in different areas of the heart cause different types of irregular heartbeats; the type of arrhythmia must be clearly defined before this procedure can be properly done.

Description

Catheter ablation involves delivering highly focused heat (or radio frequency energy) to specific areas of the heart. Radio frequency energy is very rapidly alternating electrical current that is produced at the tip of the catheter that is placed inside the heart. At the same time as the catheter is inserted, a second electrode is placed on the patient's skin. When the catheter is energized, the body conducts the energy from the catheter's tip, through the heart and to the electrode on the skin's surface, completing the circuit.
Although very little electricity is given off by the catheter, the instrument does generate a large amount of heat. This heat is absorbed by the heart tissue, causing a small localized burn and destroying the tissue in contact with the catheter tip; in this way, small regions of heart tissue are burned in a controlled manner. This controlled destruction of small sections of heart muscle actually kills the nerve cells causing the irregular heartbeat, stopping the nerve signals that are passing through this section of the heart. This usually causes the irregular heartbeat to be reset into a normal heartbeat.

Preparation

People can undergo this procedure by having general anesthesia or by taking medicines to make them relaxed and sleepy (sedatives) along with painkillers. Once the type of irregular heartbeat is identified and these medicines are given, the catheter is inserted through a blood vessel and into the heart. Importantly, correct placement of the catheter is visualized by using a specialized type of x-ray machine called a fluoroscope.

Aftercare

Being sure the patient is comfortable during and after this procedure is very important. However, because each person may have a different arrhythmia and possibly other medical problems as well, each patient's needs must be evaluated individually.

Risks

Overall, fewer than 5% of people having this procedure experience complications. The most common complications are usually related to blood vessel injury when the catheter is inserted and to different heart-related problems due to the moving of the catheter within the heart. However, in general, this technique is safe and can control many different heart arrhythmias.

Normal results

Depending upon the type of irregular heartbeat being treated, either the normal heartbeat resumes after treatment or the ability of the heart to beat on its own is lost, requiring the insertion of a pacemaker to stimulate the heart to beat regularly.

Key terms

Fluoroscope — A specialized x-ray machine used to visualize the placement of the catheter when attempting to correct irregular heartbeats.
Pacemaker — An electrical device that has electrodes attached to the heart to electrically stimulate the heart to beat normally. Pacemakers can be internal (placed under the skin) or external, with the electrodes placed on the skin or threaded through a tube placed into the heart.

Abnormal results

Additional irregular heartbeats can occur as a result of this procedure, as can damage to the blood vessels that feed the heart. Because this procedure requires the use of the x-ray machine called a fluoroscope, there is exposure to x-ray radiation, but it is doubtful that this is harmful in adult patients. The risk versus benefit is considered with pediatric patients.

Resources

Organizations

American Heart Association. 7320 Greenville Ave. Dallas, TX 75231. (214) 373-6300. http://www.americanheart.org.

ablation

 [ab-la´shun]
1. separation or detachment; extirpation; eradication.
2. removal, especially by cutting with a laser or electrocautery.
catheter ablation radiofrequency ablation.
endometrial ablation removal of the endometrium; methods used include radiofrequency, electrical energy, lasers, and hot and cold liquids.
radiofrequency ablation (radiofrequency catheter ablation) destruction of an accessory conduction pathway or other troublesome area of dysrhythmia by means of unmodulated high frequency alternating current delivered by a bipolar or unipolar catheter. The current causes heat with tissue destruction and formation of scar tissue to block the pathway or dysrhythmic area. Transvenous radiofrequency ablation has been successful in treatment of supraventricular tachycardia and is an attractive option to surgery. Called also catheter ablation.

catheter ablation

catheter ablation

A minimally invasive procedure for the treatments of supraventricular tachcardia. The procedure, performed through an intravenous catheter uses radio-frequency energy to heat and destroy a small amount of heart tissue after multipolar catheter electrode investigation has revealed the arrythmia mechanism. The scar left acts as an electrical bnarrier
References in periodicals archive ?
The Thermocool SmartTouch catheter is an important new device that will benefit the electrophysiology community, as it will enable us to more precisely control the amount of contact force applied to the heart wall when creating lesions during catheter ablation," said Andrea Natale, M.
Catheter ablation in patients with multiple and unstable ventricular tachycardias after myocardial infarction: short ablation lines guided by reentry circuit isthmuses and sinus rhythm mapping.
Its novel HeartLight[R] Endoscopic Ablation System for catheter ablation incorporates an endoscope to provide physicians with the capacity to see within the heart, and for the first time, visually direct the application of laser energy to achieve durable pulmonary vein isolation.
Catheter ablation takes about one to two hours to perform with the patient awake throughout.
As it first evolved, radio frequency catheter ablation was reserved for patients who could not tolerate or who could not be adequately controlled on drug therapy.
Topera's rotor identification system has been shown, when used with existing catheter ablation therapy, to result in positive long-term success rates, even in difficult-to-treat cases.
Use of catheter ablation is not only beneficial for treating atrial flutter but also can significantly reduce hospital visits both inpatient and emergency and lower the risk for atrial fibrillation, according to research by UC San Francisco.
professor of medicine and director of the clinical catheter ablation program at the University of Oklahoma Health Sciences Center and one of the principle investigators in the studies.
Medical Center) bring together an international group of cardiology specialists who describe catheter ablation techniques for managing cardiac arrhythmias.
Washington, May 14 (ANI): Catheter ablation, treatment of the most common heart rhythm disorder, significantly reduces the risk of stroke, mortality, Alzheimer's disease and other forms of dementia, researchers have found.
Patients with ventricular tachycardia or ventricular fibrillation do better if they undergo catheter ablation before receiving an implantable cardioverter defibrillator, according to a study of 107 patients.