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[Atrial Fibrillation/Method] |
Ablation treatment of atrial fibrillation |
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Method of ablation treatment of atrial fibrillation
Before the procedure is performed, a local anesthetic is administered to the sterilized groin area and to the root of the neck for pain relief. A catheter is then inserted, and. intravenous anesthesia is administered simultaneously so that the patient slowly falls asleep. |
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Extensive cauterization of pulmonary vein ostia for electric isolation
As indicated for the mechanism of onset of atrial fibrillation, 90% of the problems occur in the blood vessels called pulmonary veins; thus, the pulmonary veins connected to the left atrium are cauterized around their ostia.
The cauterization lines (the pink lines), made to simultaneously isolate the superior and inferior veins, illustrate the method exclusively developed by Atsushi Takahashi, the manager of our cardiovascular department.
The cauterized sites do not convey electricity and therefore electrically isolate the pulmonary veins from the heart (electric isolation of the pulmonary veins). Therefore, even if abnormal excitation occurs in the pulmonary vein, it is not conveyed to the heart and atrial fibrillation is prevented.
Nevertheless, electric isolation of the pulmonary vein is difficult to attain, and experience and knowledge are required to ensure that this technique is performed safely.
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Extensive cauterization of left pulmonary vein ostia for electric isolation
The extensive method for atrial fibrillation ablation developed by Atsushi Takahashi, manager of our cardiovascular department, is illustrated above. The method was developed after his study at Bordeaux University, France, which is the mecca for atrial fibrillation ablation.
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| Before this method was developed, we used to isolate pulmonary veins one by one. This conventional method often resulted in complications, including pulmonary vein stenosis and the failure to locate the site of excitation around the pulmonary vein ostia that caused atrial fibrillation. The permanent cure rate with the traditional method was approximately 50%. |
By cauterizing both the right and left superior and inferior pulmonary veins simultaneously , we markedly improved the permanent cure rate for atrial fibrillation to 90% , and we no longer experience complications such as pulmonary vein stenosis.
(Presented in Japanese Circulation Society and North American Society of Pacing and Electrophysiology in 2002.)
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Nonetheless, the new procedure requires more advanced techniques and cauterization of a more extensive area. These limitations have prevented the widespread use of the technique, and few facilities have been able to maintain high success rates.
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| The above chart shows where a ring shaped catheter was actually inserted into a pulmonary vein, which was isolated while we observed the electric activity of the pulmonary vein. In the fourth column from the left, electric activities were simultaneously lost in the superior and inferior pulmonary veins, so electric potential was isolated from the left atrium. |
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Atrial flutter ablation
Because atrial fibrillation is often complicated by atrial flutter, we simultaneously treat atrial flutter after by isolating the pulmonary veins after atrial fibrillation is cured. Because atrial flutter rotates around the tricuspid annulus in the right atrium, a part of the pathway should be cut off by cauterizing one line (the pink line in the above illustration). |
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Chronic atrial fibrillation involves not only the pulmonary vein but also other areas of the atrium. In addition to using ablation to cure paroxysmal atrial fibrillation (green lines in the above illustration), it is occasionally required to electrically isolate the superior vena cava, cauterize the lines shown in pink, or cauterize another site that frequently causes abnormal excitation (cauterize atrial fundamental structure).
The duration of surgery may be longer for chronic than for paroxysmal atrial fibrillation, because larger areas, need to be cauterized, and it is technically more difficult than surgery for paroxysmal atrial fibrillation .
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