ABSTRACTS

BORDEAUX, FRANCE. Most AF episodes have their origin in and around the pulmonary veins. However, AF foci have also been found on the back wall of the left atrium, the coronary sinus, the ligament of Marshall, and in the superior and inferior vena cava. Now electrophysiologists at the Hopital Cardiologique du Haut-Leveque report a case where the ectopic beats precipitating the AF originated in the left atrial appendage (LAA).

A 35-year-old woman with drug-resistant paroxysmal AF underwent a standard PVI whilst in AF. Successful isolation of all four pulmonary veins did not terminate the AF, so the EPs went looking for other sources of AF- precipitating ectopic beats. They located the source in the LAA. After successfully creating a continuous lesion around the opening of the LAA the AF ceased and the patient has now been in sinus rhythm for 5 months. The French EPs point out that isolation of the LAA is a very tricky procedure and should be considered a last option as perforation of the heart wall and damage to the phrenic nerve are very real risks.
Takahashi, Y, et al. Disconnection of the left atrial appendage for elimination of foci maintaining atrial fibrillation. Journal of Cardiovascular Electrophysiology, Vol. 16, August 2005, pp. 917-19

DUBLIN, IRELAND. The 10th annual Atrial Fibrillation Symposium was held in Boston January 14-15, 2005. An illustrious group of cardiologists and EPs exchanged information concerning remaining problems and current research into the catheter ablation of AF. Among the distinguished contributors were Pierre Jais MD, Fred Morady MD, Koonlawee Nademanee MD, Andrea Natale MD, Carlo Pappone MD, and Marcus Wharton MD. Following are highlights of the discussions:

• It is becoming increasingly clear that just isolating the pulmonary veins during an ablation may not be sufficient to result in a cure. It may also be necessary to create lesions specifically aimed at disrupting the dominant rotors in the left and right atria, or to target vagal nerve endings or ganglionated autonomic plexi in the epicardial fat pads. These approaches are currently under intensive study.

• There is intensive debate as to just how far from the edge of the pulmonary veins the ablation lesions should be placed. Placing them too close to the edge increases the risk of stenosis, while placing then too far away necessitates a greater number of "burns" in order to complete the isolation.

• There is some indication that the segmental PVI (Haissaguerre method) is more effective than the circumferential PVI (Pappone method) in reducing ectopic activity, but that the Pappone method may be more effective in inactivating the rotors responsible for maintaining AF.

• Ablation techniques at advanced centers have now reached the stage where patients with permanent AF and heart failure patients can be successfully treated. There is actually some evidence that a successful ablation may improve left ventricular function and the quality of life in patients suffering from both heart failure and AF.

• There is considerable variation in the way different centers report their success rates depending mainly on the type and duration of electrocardiographic follow-up and on the definition of success. There is recognition that success should perhaps be based on the perceived improvement in patients' quality of life. Thus, "for a patient who is transformed from a predominant pattern of highly symptomatic persistent atrial fibrillation with occasional spontaneous terminations preablation to a pattern of asymptomatic or symptomatic short-lived episodes of transient atrial fibrillation (lasting 30 seconds or 1 minute) postablation, the procedure could be deemed clinically successful."

• There is still no consensus as to the optimum type and size of ablation catheters. There is some indication that the use of an 8 mm catheter is more likely to cause blood clots than is the use of an irrigated tip catheter. The use of the intracardiac echocardiography (ICE) does not totally exclude the occurrence of the steam popping associated with excessive tissue healing.

• The creation of a fistula (hole) between the back wall of the left atrium and the esophagus is now recognized as a potential complication with often fatal consequences. It is estimated that approximately 20 cases of atrio- esophageal fistula have occurred so far worldwide. Numerous suggestions for avoiding this serious problem were discussed.

• The danger of blood clot formation at the time of penetration of the wall (septum) between the right and left atrium is high so heparin is now routinely administered immediately prior to penetration. Most centers continue anticoagulation with warfarin 3-6 months post-ablation depending on the age and risk factors of the patient and on whether or not the ablation was successful.

• New developments in the field of ablation include the combination of three-dimensional MRI and CT scans with real-time three-dimensional electroanatomical mapping. This approach could potentially eliminate the use of fluoroscopy during the procedure.

• Closure or removal of the left atrial appendage may be a viable alternative to anticoagulation for patients with persistent AF who have had a failed ablation.

Keane, D, et al. Emerging concepts on catheter ablation of atrial fibrillation from the Tenth Annual Boston Atrial Fibrillation Symposium. Journal of Cardiovascular Electrophysiology, Vol. 16, September 2005, pp. 1025- 28

Editor's comment: Much of the above information is clearly highly technical, but the fact that these topics are still being intensely debated indicate that catheter ablation still has a ways to go before being entirely successful, and that much research effort is being invested in solving the remaining problems.

BOSTON, MASSACHUSETTS. Researchers at the Massachusetts General Hospital have carried out a survey of 188 lone AF patients to determine their symptoms, triggers, medication use, and family history of LAF. Among the highlights of their findings are:

• The majority (94%) had the paroxysmal from of LAF when first diagnosed. Almost 8% of these afibbers progressed to permanent AF within a mean of 6 years of initial diagnosis.

• Average age at study enrolment was 54 years and age at first diagnosis was 45 years (range of 15- 67 years). The majority of study participants (82%) were male.

• Afibbers who had hypertension were excluded at enrolment, but 8.3% did develop hypertension during the study (2-28 years after diagnosis).

• The majority (54.5%) had experienced more than 100 episodes of AF, while 70.7% had experienced more than 20 episodes. About a third (35%) had undergone one or more cardioversions.

• Thirty-four per cent of all study participants reported having a first degree relative with AF. Only 5% of participants smoked, but 76% reported alcohol consumption. High cholesterol levels were reported by 20% and diabetes by 3.9% of participants.

• The average systolic blood pressure within the group was 124 mm Hg and the diastolic pressure average was 76 mm Hg. Average pulse rate when in sinus rhythm was 68 beats/minute.

• Echocardiograms revealed structurally normal hearts with a mean left ventricular ejection fraction of 62% and a left atrial size of 39 mm. Permanent afibbers tended to have a larger left atrium (42 mm).

• The most common triggers were sleeping (44%), exercise (36%), eating (34%), chocolate (16%), soda (11%), and coffee (9%).

• The most common symptoms experienced during an AF episode were palpitations (88%), fatigue (77%), dizziness (67%), breathing difficulties (51%), and fainting (9%). Women were more likely to experience palpitations and breathlessness than were men and were also more likely to experience frequent episodes. It is also interesting that nausea was listed as a trigger by 7% of women, but 0% of men.

• The risk of progression to permanent AF was associated with a family history of AF, having undergone one or more cardioversions, having developed hypertension after diagnosis, and having an enlarged left atrium.

• Three participants (0.6%/year) sustained a stroke during the two and a half year study period, while 2 (0.4%/year) had a documented transient ischemic attack (TIA).

• Medication usage among the participants was as follows:

• * Beta-blockers – 56.1%
• * Calcium channel blockers – 16.7%
• * Digoxin – 20.0%
• * Flecainide – 16.9%
• * Amiodarone – 13.5%
• * Sotalol – 10.7%
• * Propafenone – 7.9%

• Twenty-eight per cent of women, but only 3% of men reported having an inflammatory disease such as systemic lupus erythematosus, inflammatory bowel disease, rheumatoid arthritis, ulcerative colitis, ankylosing spondylitis or sarcoidosis. This suggests that chronic inflammation, in women at least, may be an underlying cause of LAF.

Patton, KK, et al. Clinical subtypes of lone atrial fibrillation. PACE, Vol. 28, July 2005, pp. 630-38

Editor's comment: This study parallels the findings made in our own LAF surveys. It is particularly interesting to see the genetic connection confirmed. Our LAF Survey V found that 40% of all afibbers had a first degree relative with AF. The Massachusetts survey found that 34% of respondents had such a connection. It is also interesting to note the close correlation between age at first diagnosis in the Massachusetts survey of 188 afibbers (45 years) and our LAFS-8 survey of 619 afibbers (48 years). Similarly, the percentage of men and women having AF was also very close in the two surveys (82% and 79%).

LEIPZIG, GERMANY. Most afibbers experience very obvious symptoms when they experience an episode with palpitations being the most common. Perhaps 20% of afibbers have no symptoms at all during an episode and thus suffer from what is called asymptomatic or silent AF. German researchers now report that the incidence of asymptomatic AF increases substantially after a radiofrequency ablation using the Pappone method (circumferential anatomical pulmonary vein isolation). Their study involved 114 patients with highly symptomatic AF who had experienced at least 3 documented episodes and had suffered from the condition for at least 18 months. The patients had a 7-day Holter monitoring session just prior to their ablation, immediately following, and after 3, 6 and 12 months of follow-up.

Prior to the ablation the study participants experienced a median of one episode (range of 1-3) during the 7-day Holter monitoring period. The average duration of these episodes was 38 (10-133) hours. Immediately after ablation the median number of episodes experienced over 7 days was 2 (1-5) and the duration was 36 (22-79) hours. The corresponding numbers after 3, 6 and 12 months were:

• After 3 months – 2 (1-6) episodes for a total of 23 (8-41) hours
• After 6 months – 2 (1-4) episodes for a total of 17 (8-43) hours
• After 12 months – 2 (1-5) episodes for a total of 10 (3-25) hours

The number of episodes that were asymptomatic was substantially higher after the ablation than before.

• Percentage of asymptomatic episodes before ablation – 0% (0-25)
• Percentage of asymptomatic episodes after ablation – 50% (0-89)
• Percentage of asymptomatic episodes after 3 months – 50% (0-100)
• Percentage of asymptomatic episodes after 6 months – 50% (0-100)
• Percentage of asymptomatic episodes after 12 months – 58% (0-100)

The proportion of time spent in asymptomatic AF as a percentage of total time spent in AF also increased slightly with time.

• Time spent in asymptomatic AF before ablation – 62% (6-88)
• Time spent in asymptomatic AF after ablation – 70% (10-98)
• Time spent in asymptomatic AF after 3 months – 73% (23-96)
• Time spent in asymptomatic AF after 6 months – 77% (8-100)
• Time spent in asymptomatic AF after 12 months – 77% (34-88)

Combining this information shows that the total mean duration of symptomatic AF decreased from 12 hours (during a 7-day period) prior to ablation to 2.3 hours 12 months after the ablation. A very noticeable improvement particularly in view of the fact that the researchers considered any period of rapid, irregular heart beat as an AF episode if it lasted more than 30 seconds. Nevertheless, the fact that 50% or more of AF episodes after the ablation were asymptomatic is disconcerting. It clearly impacts on success rates, which actually may be significantly lower than generally claimed. It also raises the question as to whether continued aspirin usage or anticoagulation is advisable after a circumferential, anatomical PVI.

The researchers point out that the use of beta-blockers increased substantially from prior to the ablation when 57% of participants took them to after the ablation when 77% took them. Even after 12 months 72% of participants were still on beta-blockers. It is possible that this may have reduced the intensity of episodes to the point whereby the afibber did not perceive any symptoms during an episode resulting in the episode being classified as asymptomatic.
Hindricks, G, et al. Perception of atrial fibrillation before and after radiofrequency catheter ablation. Circulation, Vol. 112, July 19, 2005, pp. 307-13

Editor's comment: The main expectation of an afibber having an ablation is that he/she will come out of it having no more symptomatic episodes. While the procedures performed in Leipzig clearly did not totally eliminate AF in all cases, they certainly made a vast improvement in regard to the average time spent in symptomatic AF. Nevertheless, the continued presence of asymptomatic episodes is disconcerting. It is possible that his phenomenon is related to the type of PVI procedure used. Another long-term study involving 165 afibbers having undergone a segmental PVI (Haissaguerre method) found that successfully ablated afibbers had very few asymptomatic episodes (only 12% of total episodes in a 30-day period) after 2 years.

FORLI, ITALY. The treatment with certain antiarrhythmic drugs, notably propafenone, flecainide and amiodarone, can result in the conversion of AF to typical right atrial flutter (AFL). AFL episodes are probably at least as uncomfortable as AF episodes, but could the conversion from AF to AFL actually be a blessing in disguise? Italian researchers believe so. Their study involved 46 AF patients (the majority with hypertension) whose AF episodes had converted to AFL episodes during treatment with propafenone, flecainide or amiodarone, or in whom AFL had been induced during an electrophysiological study. All study participants underwent radiofrequency ablation for AFL and were then followed for 1-78 months while on the same drugs prescribed for them prior to the ablation. The researchers found that 50% of participants remained AF-free, while 33% experienced a very marked improvement in their symptoms. The degree of improvement, however, declined significantly during the observation period and, after 35 months, only 8% of the patients were in stable sinus rhythm. The researchers conclude that AFL ablation and continuation of antiarrhythmic drugs may be a worthwhile first step in eliminating or reducing AF episodes in patients whose AF converts to atrial flutter either spontaneously (during drug treatment) or during an EP study.
Bandini, A, et al. Atrial fibrillation recurrence after drug-induced typical atrial flutter ablation. Italian Heart Journal, Vol. 6, July 2005, pp. 584-90
Catanzariti, D and Vergara, G. Lessons from catheter ablation: how a proarrhythmic effect has become a therapeutic chance. The case of class IC/II drugs in atrial flutter. Italian Heart Journal, Vol. 6, July 2005, pp. 591-94

Forty-five afibbers reported that they had undergone procedures other than RF ablation to deal with problems (left or right atrial flutter) arising from a pulmonary vein isolation procedure, or to achieve a cure for their afib.

The distribution of the procedures covered in this part of the survey is as follows:

A total of 15 (33%) of the procedures covered in this part of the survey (mostly right atrial flutter ablations) were followed by standard pulmonary vein ablations.

Demographics

Most of the afibbers (51%) undergoing the procedures covered in this section had the mixed (random) variety of AF. The next largest grouping was permanent afibbers at 27%, vagal afibbers at 16%, and adrenergic at 6%. Women constituted 26% of the group and the median age at diagnosis was 49 years with a range of 20-68 years. The median age at which the procedure was performed was 58 years with a range of 39-69 years.

AF Frequency & Duration

The majority of respondents (79%) experienced episodes at least once a week and 42% had daily ones (including permanent afibbers). Only 7% of those seeking a cure through the procedures covered here had episodes less frequently than once a month. This indicates that the vast majority in this group only opted for a procedure when the frequency of episodes became intolerable or permanent AF became a reality. The median duration of paroxysmal episodes was 9 hours with a range of 2-60 hours.

Evaluation of Procedure Results

Maze Procedure

The maze procedure involves open-heart surgery and the use of a heart/lung machine since the heart needs to be stopped during the procedure. After making a 10-12 inch long incision and cracking open the ribs, scar tissue is surgically created (by cutting and sewing) on the surface of the heart to make pathways connecting the sinus node and the AV node and to eliminate the possibility of aberrant impulses initiating atrial fibrillation.

Five afibbers (4 males and 1 female) had undergone the maze procedure as their first (and only) procedure, while 1 male afibber had his after previously having undergone two failed RF ablations. One procedure used laparoscopic cryo surgery and involved the use of a heart/ling machine. It was performed in April 2005, so far it looks promising, but the side effects of edema and infections in the leg and groin were fairly severe.

Of the other 5 maze procedures three (60%) were fully successful, one (20%) was partially successful, and one (20%) was a failure. These rates are comparable to those obtained at top-ranked RF ablation facilities after one or more procedures.

The three successful procedures were performed by the following surgeons:

• Dr. Patrick McCarthy – Cleveland Clinic, OH
• Dr. Dale M. Geiss – St. Francis Medical Center, Peoria, IL (2 procedures)

Three of the 5 procedures, for which the outcome is known, were not accompanied by any adverse effects, but 2 afibbers incurred a transient ischemic attack (TIA), one of which is still causing problems.

Four out of 5 patients did not experience an increase in ectopics after the procedure, but the one partially successful case did.

Two out of the 3 successful cases experienced no post-procedural AF episodes, but one did so for a month and both the partial success and the failure also did so.

None of the 3 successes were on warfarin, but both the partial success and the failure were.

Neither the complete nor the partial success needed continuing avoidance of triggers and both the complete and partially successful cases subjectively judged their surgery to have been successful, while the failure deemed it a failure.

The successful cases took between 1 and 3 months to recover their stamina, while the partially successful and failure cases took more than 3 months to fully recover.

Conclusion

Based on this rather small sample of 6 afibbers it would appear that the success rate of a single maze procedure is comparable to that of an ablation (with repeat procedure if necessary) performed at a top-ranked RF ablation center. Considering that the full maze procedure involves stoppage of the heart and the use of a heart/lung machine (with its associated potential problems), that adverse events may be more serious, and that recovery times are longer, there would seem to be little benefit in choosing a full maze procedure over a RF ablation carried out by a top EP at a top-ranked center.

Mini-Maze Procedure

This procedure is similar to the maze in that scar tissue is created on the outside of the heart rather than on the inside as is done in ablation procedures. Access to the heart is through two or more small incisions between the ribs and it is not necessary to stop the heart during the procedure. Lesions are created with a standard RF ablation catheter rather than by cutting and sewing. The left atrial appendage, a small pouch where blood clots tend to form, is also removed during the procedure.

Seven afibbers (2 females and 5 males) had undergone the mini-maze procedure as their first (and only) procedure, while one male afibber had his after two failed RF ablations. One of the procedures used microwaves for ablating, but as it was only done in May 2005 it has not been included in the evaluation of overall success rate.

Of the 7 remaining, 6 (86%) were fully successful and the remaining 1 (14%) was a failure. The success rate of 86% with just one procedure is superior to that obtained at top-ranked RF ablation centers using one or more procedures. I believe only the very best EPs would be able to equal it.

The 6 successful procedures were performed at the following institutions:

• Ohio State University - Dr. James Cox
• University of Cincinnati - Dr. Randal Wolf (2 procedures)
• Medical City Hospital, Dallas, TX - Dr. Michael Mack
• Holy Cross Hospital, Fort Lauderdale, FL
• James Cook University Hospital, UK - Dr. Steve Hunter

Five of the 7 procedures were free of adverse events, while 1 was accompanied by a major accumulation of blood in the chest cavity and 1 resulted in a shingles-like nerve pain. Neither of these adverse effects were fully resolved 7 months post-procedure.

Six out of 8 patients did not experience any increased ectopic activity after their procedure, while 2 did experience some for less than a month post-procedure. Three of the successful cases experienced no post- procedure AF episodes, 2 experienced them for less than a month, and 1 experienced them for more than three months.

All the successful cases were off warfarin, while the unsuccessful case was still on warfarin. Most successful cases (4 out of 6) no longer needed to avoid previous triggers, while the remaining 2 were not sure. The unsuccessful case still needed to avoid known triggers.

The recovery time varied considerably. Among successful cases one recovered after 1-2 months, two recovered after 2-3 months, one recovered after 3 months, and two needed more than 3 months to recover.

Conclusion

Based on this rather small sample of just 8 afibbers, it is evident that the mini-maze is a highly successful procedure when carried out by a skilled cardiac surgeon. Recovery times are somewhat longer than for RF ablation and side effects can be more serious, but radiation exposure is likely to be negligible to nil. Overall, the mini-maze will no doubt soon emerge as a worthy competitor to RF procedures done at top-ranked institutions. However, not many cardiac surgeons have extensive experience with the procedure, so it is important to either wait a while or choose a surgeon who has already performed a hundred or more.

Cryoablation

The cryoablation procedure is similar to the standard RF ablation procedure except that the ablation catheter is nitrogen-cooled rather than electrically-heated. The advantage of cryoablation is that it reduces procedure stroke risk and does not create pulmonary vein stenosis even if the ablation is done inside the pulmonary veins themselves.

Three male afibbers reported having undergone cryoablation as their first procedure. Two had the mixed variety of AF and one was vagal. One procedure was performed in the early days of cryoablation (April 2000) and was not successful. It was followed by two segmental pulmonary veins ablations which were also unsuccessful. One procedure, carried out by Dr. Gregory Feld at the University of California at San Diego, was successful with no adverse effects. The remaining procedure was done in connection with an aortic valve replacement procedure and the patient remains on amiodarone one year post-procedure. Both left and right atrial flutter was introduced by the procedure.

Conclusion

It is clearly not possible to conclude anything about the success rate of cryoablation based on just 3 cases.

AV Node Ablation + Pacemaker

Another approach to eliminating the effects of the fibrillation of the atrium on ventricular beats is to isolate the AV node (the ventricular beat controller) from any extraneous impulses and feed it its marching orders from an implanted pacemaker. This procedure has three major drawbacks:

• It does nothing to stop the fibrillation of the atria, which in itself can be quite uncomfortable, and necessitates continuing anticoagulation (warfarin) therapy.
• It makes the patient entirely dependent on the pacemaker. If it malfunctions or the batteries run out the patient dies.
• It does nothing to remedy the fatigue and reduced exercise capacity caused by the fibrillation of the atria.

AV node ablation is performed in much the same way as a RF ablation except that it is the area around the node that is ablated. A recent study found the procedure to be relatively safe for patients with lone AF, but another more recent study concluded that the procedural mortality rate is about 2.1%. Although AV node ablation and pacemaker implantation does improve the quality of life, it is still considered a last resort approach, especially for lone afibbers.

Two male afibbers (1 permanent, 1 vagal and both with no underlying heart disease) had undergone AV node ablation and pacemaker installation with no adverse events. They are both on warfarin (permanently), but are not taking antiarrhythmics or blockers and are not experiencing symptomatic AF episodes. They no longer need to avoid previous triggers. Thus, within the above-mentioned limitations, these two procedures were successful.

Right Atrial Flutter Ablation

Atrial flutter and AF are similar in that they both involve abnormal, sustained, rapid contractions of the heart's upper chambers (atria). In atrial flutter the atria contract 220 to 350 times a minute in an orderly rhythm. In AF the rate of contraction may be as high as 500 beats/minute and the rhythm is totally chaotic. The two arrhythmias can both occur as a result of an enlarged atrium or in the aftermath of open-heart surgery, but the mechanism underlying them is quite different. Nevertheless, they can coexist in the same patient and one may convert to the other.

There are two major types of atrial flutter – common or type 1 and atypical or type 2 flutter. Type 1 flutter is by far the most common (65-70% of all cases) and is characterized by a specific conduction abnormality in the lower right atrium. Type 2 or atypical flutter, on the other hand, has no easily discernible origin and is therefore harder to deal with.

Because the location of the origin of atrial flutter, at least in the common type, is so well known and consistent from patient to patient radio frequency catheter ablation can be used with considerable success to permanently eradicate atrial flutter. Unfortunately, this procedure is unlikely to cure AF, which may often coexist with atrial flutter. There is also some evidence that atrial flutter patients who have a successful ablation increase their risk of later developing AF by 10-22%. So undergoing RF ablation for atrial flutter may not remove the necessity of dealing with AF.

Because of the close connection between AF and atrial flutter, it was quite common, in the early days of ablation, to perform an atrial flutter ablation in the hope that it would cure the AF. The atrial flutter ablation involves only the right atrium so there is no need to pierce the septum to the left atrium as is done in a PVI. Despite the 1998 discovery by Prof. Haissaguerre that 80-90% of all AF episodes are initiated in the pulmonary veins (left atrium), right atrial flutter ablations are still carried out today in an attempt to cure AF. They are also performed in cases where the patient suffers from right atrial flutter or a combination of AF and atrial flutter.

Sixteen (13 males and 3 females) had undergone a right atrial flutter ablation as their first procedure. Of these one (female) had a successful right atrial flutter ablation and an ablation for PVCs and now has no further problems. One (female) had a successful right atrial flutter ablation which also cured AF. The remaining 14 had both AF and flutter and the flutter ablation, while in most cases (85%) curing the flutter, did not cure the AF. Eleven of the 14 went on to have RF ablation for AF, while one had a repeat atrial flutter ablation.

The majority (75%) experienced no adverse events related to the flutter ablation. Three patients (19%) experienced hematomas in the groin and thigh area, while one developed left atrial flutter/tachycardia.

Four afibbers developed atrial flutter after their PVI procedure and were successfully ablated for right atrial flutter. It is interesting to note that only one of the 20 right atrial flutter ablation procedures was carried out at a top-ranked institution.

Conclusion

Right atrial flutter ablations are generally successful in curing the flutter, but only very rarely (1 in 15) cures coexisting AF as well.

Left Atrial Flutter Ablation

Left atrial flutter is considerably less common than right atrial flutter, but can also occur as a result of a PVI procedure. The PVI-related left atrial flutter may disappear on it own over a 6-month period or so, but some cases require a repeat ablation to fix the flutter.

Two respondents had left atrial flutter as their primary condition and were successfully ablated for this. One of them also had AF and was successfully ablated for this as well.

Three of the respondents who developed left atrial flutter as a sequel to their AF procedure had a successful follow-up procedure to eliminate it.

Conclusion

Left atrial flutter can occur as a sequel to an AF ablation. In many cases it disappears on its own, but in some cases a repeat ablation is necessary to correct the flutter. This procedure (based on a very small sample size) is usually successful.

Other Procedures

One successfully ablated afibber had a follow-up ablation (successful) for supraventricular tachycardia.

SUMMARY

A total of 45 procedures other than RF ablation was carried out in order to eliminate AF or conditions arising from a PVI procedure. The following observations were made:

• Based on a very small sample (6 procedures) it would appear that the success rate of a full maze procedure is comparable to that of a RF ablation (with repeat procedure as necessary) performed at a top-ranked institution.

• Based on a small sample (8 procedures) it would appear that the mini-maze is a highly successful procedure when carried out by a skilled cardiac surgeon.

• There were only 3 responses from afibbers who had undergone cryoablation, so it is not possible to draw conclusions regarding the success rate and safety of this procedure.

• Two responses were received from afibbers who had undergone AV node ablation and pacemaker implantation. Both procedures were successful and eliminated symptomatic AF. Nevertheless, this procedure remains the procedure of last resort.

• Twenty respondents had undergone a right atrial flutter ablation either as a follow-up to a PVI procedure, in an attempt to cure associated AF, or to eliminate atrial flutter on its own. Procedures were generally successful as far as eliminating flutter is concerned, but very rarely cured coexistent AF.

• Five respondents were successfully ablated for left atrial flutter either precipitated by a PVI procedure or present as a primary condition.

• One successfully ablated afibber had a successful follow-up ablation for supraventricular tachycardia.

This concludes the evaluation of the responses received in the 9th LAF Survey. Again, my sincere thanks to all those who participated.