Heart Rhythm Society Convention – 2002
The topics covered under this section are:
- Improved A-Fib procedure from the French Bordeaux group
- Segmental Ablation may have more advantages for patients than Circumferential ablation
- New ablation procedures being developed are Cryoablation, Laser Ablation and Ultrasound Ablation
- ICDs set to pace before they shock reduce the number of painful shocks by 80 percent
Improved A-Fib Procedure—NASPE Convention, San Diego, Ca. May 8, 2002
In perhaps the most important research development in A-Fib this year, Dr. Pierre Jaïs of the French Bordeaux group announced a major improvement in Pulmonary Vein Ablation of A-Fib. At the North American Society of Pacing and Electrophysiology Convention in San Diego, CA May, 2002, Dr. Jaïs announced that the Doctors in the Bordeaux group are currently performing Catheter Ablation of the Pulmonary Veins using Pulmonary Vein potentials (Segmental Ablation) combined with linear ablation of the “Left Atrial Isthmus. After first ablating any areas of the Pulmonary Vein openings with Pulmonary Vein Potentials, they then make a linear ablation line between the ostium of the Left Inferior Vein and the Lateral Mitral Annulus using a cooled tip catheter. This significantly improves their success rate in curing A-Fib.
The Bordeaux group also seems to have raised the bar for measuring success in treating A-Fib. They now measure success not simply in eliminating Pulmonary Vein Potentials, but rather in restoring patients to normal sinus rhythm without dependence on any medications. Dr. Jaïs reported success rates of 85% in curing patients with Paroxysmal A-Fib. This is a remarkable success rate. What this means for patients with A-Fib is that soon one or two visits to an A-Fib facility for what will become a routine procedure will eliminate A-Fib in nearly all cases.
Segmental vs. Circumferential Ablation—NASPE Convention, San Diego, Ca. May 9, 2002
In an unusual format for a medical convention, NASPE sponsored a debate on Segmental versus Circumferential Ablation of the Pulmonary Vein Openings to eliminate A-Fib. The participants were Dr. Andrea Natale of the Cleveland Clinic Foundation arguing on the side of Circumferential Ablation, and Dr. Pierre Jaïs from the Hôpital du Haut-Lévèque, Bordeaux (Pessac), France arguing in support of Segmental Ablation.
(“Segmental Ablation” refers to a technique of Focal Ablation in which Pulmonary Vein Potentials in the heart are individually identified and ablated, thereby eliminating the sources of A-Fib signals in the heart.
“Circumferential Ablation,” rather than pinpointing Pulmonary Vein Potentials in the heart, uses a circular catheter to ablate each Pulmonary Vein Opening (Ostium) in the heart. This procedure “isolates” the Pulmonary Vein Openings so that A-Fib signals from the Pulmonary Vein Openings can not get into the rest of the heart. See Focal Ablation.)
Though the jury is still out on the merits of each of these procedures, in this author’s opinion patients with A-Fib are probably better served by medical facilities that use Segmental rather than Circumferential Ablation. To quote Dr. Jaïs, “Why use a cannon to shoot an ant?” Circumferential Ablation applies RF energy to the entire Pulmonary Vein Opening (Ostium) rather than just to individual areas of the Pulmonary Vein Openings that have potentials. This increases the risk of Pulmonary Vein Stenosis—a swelling and narrowing of the Pulmonary Vein Openings which restricts blood flow into the heart. PV Stenosis can lead to fatigue, flu-like symptoms and pneumonia.
An additional problem with Circumferential Ablation is that the Pulmonary Vein Openings are not always smooth and oval. With current techniques it is not always easy to make continuous circular ablation lines. Because the actual focal points or sources of A-Fib signals are not destroyed as in Segmental Ablation, any break in the Circumferential Ablation line can lead to more A-Fib. Dr. Natale illustrated how in some veins, in order to better achieve a continuous circular ablation line, he inserted the circular catheter inside a Pulmonary Vein Opening. But the further you move a circular catheter into a Pulmonary Vein Opening and ablate, the greater is the risk of PV Stenosis.
Segmental Ablation takes more time and effort, but currently seems to be better for patients than Circumferential Ablation.
New Ablation Techniques—NASPE Convention And Exhibits, San Diego, CA, May, 2002
There are several ablation procedures being developed and tested which may significantly improve results for patients with A-Fib. They are:
- Laser Ablation
- Ultrasound Ablation
RF energy used in current ablation techniques creates a burn in heart tissue thereby destroying the areas of the heart that produce A-Fib pulses. This burn can cause swelling and narrowing of the Pulmonary Vein Openings sometimes resulting in what is called PV Stenosis. Also, particles of burnt tissue debris from RF Ablation may get into the blood stream thereby causing blockages and even stroke. Current RF Ablation techniques use cooled-tip and low wattage catheters to avoid these problems.
Cryoablation, by freezing heart tissue rather than burning it, has the potential of eliminating the swelling (Stenosis) after ablation. Laser and Ultrasound, by not damaging the surface of heart tissue, have the potential of eliminating the damaged tissue debris that may get into the bloodstream when using RF Ablation.
We will follow the development of these ablation techniques closely. They may significantly improve the treatment of A-Fib.
Pace First ICDS—NASPE Convention Press Briefing, San Diego, Ca, May 9, 2002
The author of this Web site doesn’t recommend current Implantable Defibrillator technology for the normal treatment of A-Fib (See Implantable Defibrillator). However, new research presented at NASPE may lead to ICDs becoming a viable option for A-Fib.
“ICDs should routinely be set to pace before they shock,” according to Dr. Hugh Calkins of Johns Hopkins Medical Institutions, Baltimore, who presented the results of the two year Low Energy Safety Study.
About 250,000 ICDs (Implantable Cardioverter Defibrillators) are in use today, and virtually all of them can use low energy electrical impulses to painlessly pace the heart in an attempt to terminate an abnormal rhythm. “Trying pacing first takes a total of 15 to 30 seconds,” said Dr. Calkins. “There appears to be no downside to trying pacing first, yet there are two major upsides — no pain for the patient and less drain on the ICD battery when pacing alone is used.”
ICDs are normally implanted in people at risk for sudden cardiac arrest because the heart (the ventricles) starts beating too fast. Pacing first before shocking corrected this arrhythmia problem 80 percent of the time, thereby cutting down by 80 percent the number of painful shocks a patient received. More importantly, when the shocks did occur, they corrected the arrhythmia. No one in the two-year study died.
In this Web site’s section on Implantable Defibrillators this author suggests that, for most A-Fib patients, ICDs are not currently a probable option. Most people would rather have A-Fib or pursue other procedures for curing their A-Fib rather than being shocked by an ICD which can be painful, like being “kicked in the chest.” Since A-Fib is normally not a life threatening arrhythmia, there is no need for an ICD and painful shocks when other procedures for curing A-Fib will work. However, “pacing first” ICDs are an important first step in making ICDs a viable option for treating A-Fib. Perhaps someday the pain from the ICD shocks can be eliminated as well.
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Last updated: Sunday, February 15, 2015