Catheter Ablation: Heart Rhythm Treatment

Radio Frequency catheter ablation in Portland, Oregon is performed by electrophysiologists; cardiologists with specialized training in the diagnosis and treatment for heart rhythms, Dr. Ashkan Babaie and Dr. Alexi Zemsky in northeast Portland.

As previously stated, several types of catheter ablation may be performed, depending on the cause and severity of the patient's heart rhythm disorder. Many types of heart rhythm disorders may be treated successfully by catheter ablation. Some patients may still need treatment with medications or implantable devices after the procedure.

We'll tell you a little more about catheter ablation for specific heart rhythms.

Catheter ablation is often an effective cure for bothersome heart palpitations. Electrophysiology, cardiology physicians can advise patients on the most appropriate treatment for their specific condition. The important thing is to seek the advice of a trained heart rhythm doctor

The risks and complications such as heart injury or infection are uncommon. The electrophysiologist will discuss with you the potential risks of the procedure.

Catheter ablation has numerous advantages:

------- It can permanently interrupt the triggers of heart arrhythmia; many patients require no further treatment.
------- It can restore a regular, coordinated heartbeat.
------- For many patients, it brings freedom from long-term use of blood-thinning medications.
------- The procedure is minimally invasive, and no open-heart surgery is needed.
------- There is reduced risk to the patient, compared to surgery.
------- The patient typically has little or no pain.
------- Recovery is relatively fast; most patients leave the hospital shortly after the procedure, or just one or two days following. They are able to resume normal activities a few days after the procedure.

Atrial arrhythmias such as atrial tachycardia, flutter or fibrillation can usually be treated with antiarrhythmic drugs or cured with a catheter ablation.

In some patients this is not possible and other alternatives are sought. In these cases it acceptable to allow the atrial arrhythmia, usually atrial fibrillation or atrial flutter with a rapid ventricular response, to occur and use medications (digitalis, calcium or beta blockers) to slow the ventricular response.

In some patients, however, this strategy is either ineffective or the medications used cause side effects that the patient does not tolerate well. An alternative strategy of destroying the AV node with ablation producing complete heart block and placing a pacemaker is a good one in these instances. Although this does not cure the atrial arrhythmia, it relieves most ,or all, of the symptoms by slowing the ventricular response and making the pulse regular .

After this procedure, heart rhythm medications are stopped. Since the pacemaker senses patient motion and/or breathing rate, it will increase the heart rate to help the patient exercise. The chance of success of this ablation is about 97% .when RF energy was used in a large multicenter registry (1).

The AV node is easily accessed through the femoral vein in the crease of the groin. For 95% of patients, the AV Node is located in the right atrium. In the other 5%, the left ventricle is accessed via the femoral artery where the HIS bundle can be ablated.

The risk of AV node ablation is less than 1%.
The risks of the pacemaker are also about 1% and include death, stroke, damage to heart, lung, blood vessel or nerve, bleeding or infection.

About 85% of patients feel much better after this procedure. About 10% of patients do not feel much better, and 5% admit to feeling worse. Unfortunately, there is no way to predict which patient will feel better and which will not. In nonresponders, sometimes upgrading the pacemaker to a biventricular device allows for better timing of the heart's contractions. This kind of pacemaker includes pacing from both the right and left ventricle to create the most effective synchrony of the contractions .

(1.) Scheinman M and Huang S. The 1998 NASPE prospective catheter ablation registry. PACE 2000; 23: 1020-1028
Results of a large multicenter registry of RF ablation including ablation of the AV node

AV node ablation with pacemakers - AV node ablation can generally treat atrial flutter and atrial fibrillation. In AV ablation, a catheter is placed near the atrioventricular (AV) node (the electrical connection between the atria and ventricles). Radiofrequency energy is applied through the catheter to destroy the AV node, preventing the atria from sending electrical impulses to the ventricles.

Often doctors implant a pacemaker prior to the AV Node ablation to establish a regular rhythm. Patients will need to use a pacemaker for life. Anticoagulation (blood-thinning) medication is still required after the procedure to reduce the chance of developing blood clots.

There are several different catheter ablation techniques used to cure atrial fibrillation.

Focal and circumferential catheter ablation are used to try to cure atrial fibrillation. Focal ablation, also known as targeted ablation, is used to destroy the specific areas in the heart that are firing off abnormal electrical impulses and causing atrial fibrillation. Sometimes, abnormal impulses come from inside a pulmonary vein and cause atrial fibrillation. Catheter ablation in a pulmonary vein can block these impulses and keep atrial fibrillation from happening. Circumferential ablation is used to destroy the tissue that lets atrial fibrillation continue. Sometimes, a doctor uses both focal and circumferential ablation.

The most commonly used techniques involve ablation of the connections between the pulmonary veins and the left atrium (pulmonary vein isolation), or a wide circumferential ablation around the pulmonary veins. The goal is to electrically isolate electrical signals arising from inside the veins, or adjacent to the pulmonary vein openings, from the rest of the left atrium.

A pacemaker is usually not needed when catheter ablation is done on the pulmonary vein or other targeted tissue

Catheter Ablation is an exciting new treatment available for patients with atrial fibrillation.

Although antiarrhythmic drug therapy has been the mainstay for treatment of atrial fibrillation, it is often ineffective in maintaining sinus rhythm. For such patients rate control with calcium channel blockers and beta blockers can be a reasonable alternative, though many patients remain symptomatic on these therapies. Additionally many patients experience intolerable side effects from antiarrhythmic drugs. In such patients, catheter ablation should be considered as the only potentially curative therapy for atrial fibrillation. In fact the most recent ACC/AHA guidelines include catheter ablation as a treatment option in these types of patients.

In most patients atrial fibrillation originates from the pulmonary veins near their junction with the left atrium. Rapidly firing foci from one or several veins cause atrial fibrillation. Catheter ablation involves electrically disconnecting these veins from the rest of the atrium by radio frequency ablation. For more complex cases, additional ablations need to be given in various parts of the right and left atria.

The procedure is done percutaneously via catheters in the femoral and internal jugular veins. The procedure generally lasts 4 to 5 hours and requires an overnight hospital stay. The chief risks of the procedure are stroke and cardiac tamponade. The success rate for the procedure in patients with paroxysmal atrial fibrillation is approximately 70 to 80 percent and in chronic atrial fibrillation approximately 40 to 50 percent. Patients are frequently able to discontinue antiarrhythmic medication. More data is needed to assess the safety of discontinuing coumadin therapy after a successful ablation. The management of atrial fibrillation continues to evolve as ongoing trials compare drug therapy to catheter ablation.