On Time, Technology, and The War of the Worlds

It seems so sudden, this shortening of the days.

It is dark now where it was once light, yet the days remain fixed at 24 hours. You reflect, and think about time: time for light, time for leisure, time for family, and time for work.

Time for doctors is the incessant foot soldier, marching relentlessly as one day moves to the next. Increasingly, doctors (especially proceduralists like myself) are compensated, in part, based on productivity. Such a model is limited by the time available, by its vary nature. So in order to remain income-neutral as insurance payments have dwindled, doctors historically have been pressed to do more in less time. In most instances we have managed, but the margins for doing more within the same fixed 24 hours of time has reached its limits.

Consequently, I wonder what my profession will look like in five or ten years.

It is interesting to see the promotion of atrial fibrillation ablation and cardiac resynchronization devices for heart failure begin to take the forefront of cardiac electrophysiology. But these more complicated procedures also take much more time to perform than a comparable catheter ablation procedure for supraventricular tachycardia or a standard pacemaker for heart block. Not surprisingly and likely in large part due to the push by government payers to limit expenditures to proceduralists like myself, a serious discussion is now being had across the country by subspecialists: offer more complicated procedures which pay much less per hour spent, or funnel these cases to specialized centers in favor of cherry-picking the simpler procedures.

Such a strategy also plays into the hand of high-tech developers in my field nicely. Increasingly, we have seen a large marketing push to promote either the stiff-cathetered Hansen Medical steerable sheath in the heart or blood vessels, or the spaghetti-noodle-soft catheter of the Stereotaxis system which is steered within the heart using a super-magnet and driver motor. But what I have been noticed is these technologies have not launched to the level I would have expected if they had delivered a true paradigm shift to the way we ablate arrhythmias.

Why?

While these technologies are fascinating and make for great promotional material for hospitals, they address a problem few electrophysiologists feel they have a problem with: steering a catheter. Unlike the 3-D mapping systems like Biosense Webster's Carto system, or St. Jude's Ensight system that help us understand the anatomy and physiology of arrhythmia processes (and therefore have value-added benefit to the electrophysiologist), catheter-moving robotic technology has so far added little to the ability of electrophysiologists to correct the underlying rhythms being treated. Additionally, cost has been a barrier to market entry, with Hansen's system costing somewhere in the neighborhood of $600,000 US and, Stereotaxis's system costing significantly more since special construction and non-magnetic equipment is required to install their system.

But there's still a more pressing barrier to entry for these technologies now: time.

These devices take time to set up, time to train personnel, time to wait for the anesthesiologist, time to move the other non-robotic catheters used in the case, and more time to move the robotic catheter from point A to point B. As such, they have not yet delivered on the promise to be more efficacious or expeditious than our manual ablation techniques. They have not simplified our complicated procedures but rather complicated them.

This is not to say that ablation cannot be performed with these robotic systems. Certainly they can. But to the average electrophysiologist interested in getting their work done well and getting home in time to see their kids before bedtime, or to the hospital administrator interested in increasing their productivity in an existing lab, these devices have yet to deliver improved efficiencies or effectiveness compared to manual procedures. I even heard one hospital administrator snicker that they're aware of more than one specially-constructed laboratory sitting idle as doctors resist its use in favor of a conventional facility. Does this mean for doctors whose hospitals purchase these systems that they'll be forced to used them? Will the companies push Medicare to developing a reimbursement code to that there will be an economic incentive to use them?

In H.G. Well's War of the Worlds, a simple, unappreciated bacterium ultimately destroys invading powerful alien creatures that arrive in London. For these robotic catheter-driving technologies, time, especially procedural time, has become the simple under-appreciated bacterium that might affect their survival as well. While any new technology carries a learning curve, unless they offer improved time or outcome efficiencies, they will be bypassed for more conventional approaches. What is clear, is that few hospital administrators will want to purchase them if they're just doing to store these expensive technologies in a closet.

-Wes

Image reference: Wikipedia.

How to Make an Expensive Procedure Even More Expensive

... just add a robot.

(At least the pictures are pretty cool... Now, looking at slide 10, I don't see atrial fibrillation, so I wonder what was ablated? An atrial tachycardia?)

-Wes

New Technologies for Atrial Fibrillation Ablation

One of the highlights of the Heart Rhythm Society 2008 meeting in San Francisco was the “EP TV” live cases performed today. In the morning were two ventricular tachycardia cases, and the afternoon, two atrial fibrillation ablation cases. They were professional and very well-attended.

One of the more interesting interactions occurred in the afternoon atrial fibrillation case discussions which included doctors Warren M. “Sonny” Jackman, MD (Oklahoma City, OK), Fred Morady, MD (Ann Arbor, MI), Andrea Natale, MD (his lab was operating – Austin, TX), Douglas Packer, MD (Rochester, MN), and Koonlawee N. Nademanee, MD (Inglewood, CA) as panelists and John D. Day, MD (Salt Lake City, UT) as moderator. There were two paroxysmal atrial fibrillation cases being performed – one with manual catheter manipulation and CartoSound ultrasound image development, and the other using the Hansen robotic mapping system coupled with the ESI Nav-X 3D mapping system that used their new “Fusion” software to superimpose a pre-procedural-obtained CT volume rendered image over the Nav-X geometry.

I have attempted to paraphrase the commentary (taken from notes taken) in response to a question e-mailed to the participants from the audience:

“What does the image overlay and all of this technology add to doing this procedure?”

Jackman: Well, with the known limitations of registration with these systems, I am cautious when using them. CartoSound is okay, because you’re imaging the surface of the heart directly. And certainly pre-operative CT imaging is helpful to understand the anatomy. But I would have wanted to get a feeling for this arrhythmia first (the patient was in sinus rhythm at the time) – I would want to initiate the rhythm first to see if there might be something I might understand to ablate before proceeding with the whole afib ablation. I might not find anything else most of the time, but if I did it’d be helpful.

Nademanee: I just use Carto to create a very simple map – you know, the His, CS, and pulmonary veins and use about 6-7 minutes of fluoro for the whole case after the geometry is developed – I don’t think Stereotaxis would help reduce that time very much. I use image guidance with fluoro, because my technique uses electrograms and I’m going to move that catheter because my technique relies on proper electrograms.

Morady: I don’t think there is a dispute over the role for 3D mapping of the left atrium – it cuts down on fluoro, and registering the locations of the ablation points is helpful. The extra imaging with “Merge” and CartoSound is nice but it could be that a mistake if 1-2 mm will be the difference between thinking you’re in the left atrial appendage or the ridge outside the left superior pulmonary vein. We still need a cost-benefit evaluation. Will outcomes be better? I don’t know. In the top labs around the world, they’ve ben doing a pretty good job already – it’s hard for me to think it’ll be improved with this technology.

Day: Andrea, tool or toy?

Natale: In the hands of people who do this everyday, it might not be that helpful, but for people who don’t do it everyday, I think it will be useful.

Packer: I agree with Fred’s (Morady) comments. In the more complicated cases, the utility of 3D images increases our success we think. We’ve done validation (on accuracy) with CT images. CT’s are yesterday’s news, ultrasound is today’s. Ultrasound gives about a 2mm error, vs. 3D mapping systems that give 6-8 mm error. How fast can we do it? How much does it cost. We’ve found we’re doing less pre-procedure CT’s with ultrasound now… The utility of all of this will need to be sorted out in prospective randomized trials…

Hopefully this will give a flavor for their enthusiasm. Consider purchasing the actual CD for the actual conversations from the Heart Rhythm Society if you’d like to hear more…

-Wes

Addendum: The funniest moment of the whole event was when Rodney P. Horton, M.D was introducing his atrial fibrillation case. Imagine, a room the size of two or three football fields full of cardiac electrophysiologists from around the world, analysts from every major venture capital firm in this space, and tons of industry personnel - all whom have collectively performed thousands upon thousands of catheter ablation procedures for atrial fibrillation. Then Dr. Horton says:

"...atrial fibrillation is an experimental procedure and is not approved by the FDA..."

and there, lying on the table is a patient with a Hansen robot in their leg (approved by the FDA) and an ESI mapping system (approved by the FDA) mapping their heart.

The whole room started quietly chuckling...

...like anyone cared. Now, it seems, every operation performed in the US will have to be "approved by the FDA" before it can occur.

-Wes

Lost in Space

Monday I traveled to Minneapolis to tour Boston Scientific and learn about the "project Aurora" initiative to clean up their shortcomings that lead to an FDA warning letter which halted their production line. (They devoted some 600 engineers and $140 million to "re-vitalize" their business, they said.)

But along the way, I had the chance to meet with many other electrophysiologists (we call them EP's) from the Chicago area - good guys all - each at the top of their "game," so to speak. We discussed the the future of our field: new ideas and innovations. And naturally, up came the subject of "robots" - specifically robotic assistance for catheter ablation - especially atrial fibrillation. Two main companies are in this space right now, Sterotaxis, that uses some big magnets to move a magnetic catheter in 3D space, and Hansen Medical that uses a motorized robotic sheath system to steer a catheter in 3D space (I blogged on this earlier). Here was the discussion that transpired:

"Yeah, we're going to have two new ones later this year."

"Our center is moving to some new labs and we'll have one, too."

"Is there any data to demonstrate efficacy with these devices?"

"Not in any prospective, randomized, multi-center way, no."

"Do you think these things will help?"

"I don't know. But it'll be cool to play with 'em. I'm looking forward to having an opportunity to really see the potential of this technology. Certainly, the hospital likes the marketing opportunities..."

"But do they work? I mean, for $1.5 million and a special non-magnetic room and all..."

"We'll have to see. Our center got one donated through a grateful patient, so our return on investment will be immediate via marketing. I mean, it's almost like you have to have it to say you're on the 'cutting edge.'"

"Why haven't there been any multi-center studies with these things?"

"Simple. They really don't want to do those studies. They're expensive. Why would a company want to spend the money to study them when centers are buying them anyway? Everyone wants to say they are on the 'forefront' of medicine, right?"

I mean, technology is so sexy, isnt it? Multiple computer screens, 3D graphics, joy sticks with multiple degrees of freedom and pre-designed programs, built on models, that move a stick in 3D space using cool whirring motors or magnets. I mean "pulling" the catheter where you want to go - what could be better?

And I can sit down! No more hemorrhoids! No more swollen legs!

But realistically, each system has its limitations. I have already mentioned some of those seen with earlier iterations of the Sterotaxis system, and Hansen has been plagued by rumors of cardiac perforations.

In the old days of EP, catheter ablation defined itself by number of radiofrequency applications (less was better to minimize injury to the heart), procedure times, acute and long-term procedural success. Are ablation times shorter with robots, hmmm, haven't heard. Better outcomes? Nothing. I have heard about the "learning curve." One novice doctor noted it was hard to even move the catheter to the His bundle position with one of the systems when he tried since this location was not "pre-programmed."

And yet these devices are "approved" by our FDA. Deemed safe, effective by a 510(k) approval process that states:

A 510(k) is a premarket submission made to FDA to demonstrate that the device to be marketed is at least as safe and effective, that is, substantially equivalent, to a legally marketed device (21 CFR 807.92(a)(3)) that is not subject to PMA (pre-market approval). Submitters must compare their device to one or more similar legally marketed devices and make and support their substantial equivalency claims.

Safe and effective perhaps for simple atrial flutter ablation, but atrial fibrillation? Really? How many cases were submitted to the FDA? Twenty?

Now I am no Luddite when it comes to all things technical. I love technology. And I certainly think that studying these devices to determine safety and efficacy should be done.

But I see a trend now where the amount of heart destroyed doesn't matter (some feel if enough ablation is performed, all afib will eventually cease - and they're probably right - but what about atrial transport?) Marketing, marketing, marketing of the latest, yet not necessarily the greatest robot, seems to be the norm. Science and the rigor required to determine efficacy and safety are squeezed by ever-tightening research budgets while companies are permitted to expand without demonstrating superiority, only equivalency.

And it all costs our patients (via the Medicare National Bank) millions and millions of dollars.

-Wes

Image reference.

Calling Dr. Pappone

Alexis Madrigal seems to want to get Carlo Pappone, MD to respond to his post on Wired magazine's blog regarding Hansen's robot-assisted atrial fibrillation ablation device.

Will he respond? Or was the demo nothing more than ill-conceived marketing hype?

-Wes

5 Nov 2007 @ 1930: Mr. Madrigal's update.

Robotic Marketing

Imagine buying a Mercedes Benz luxury car to take a trip. You save your hard-earned cash and spend handsomely for the car because of its human engineering, reputation and admire its comfort during a test drive. You drive it from the dealer and find the car’s the rage as it sits in your driveway. You gloat over its finish and detailing. You’re the envy of the neighborhood.

And then you find out the trip is a transatlantic one, and you should have bought a boat instead.

Such is the lure of technology in medicine. It seems all too often the development, manufacturing, and marketing of devices, especially high-tech robotics, has exceeded our understanding of the mechanisms and etiologies of the very diseases we hope to treat. And it is sexy.

But others have argued that such technology does nothing but contribute to hospitals' technical arms race.

Such is the case of atrial fibrillation ablation.

I am struggling with the decision of obtaining a device to perform robotic-assisted catheter ablation of atrial fibrillation. There are several devices now on the market. One is a mechanical robotic sheath system from Hansen Medical that purports to "extend my reach" to locations within the left atrium better and with more precision, and the other a system from Stereotaxis that uses a powerful magnetic field to provide "a softer touch to the treatment of heart disease."

Both systems have their pros and cons. Both are expensive.

But despite huge leaps in our understanding of atrial fibrillation and its mechanisms, the more I understand the arrhythmia, the more I have come to believe that we still don’t understand the mechanisms at play in the individual patient. For instance, why do some patients with normal-sized hearts get atrial fibrillation while others do not? Why do some patients with huge left atria from mitral stenosis sometimes never manifest the arrhythmia, while others are debilitated by it? What are the long-term mortality data with ablation compared to drug therapy? With the complications of the procedure (which admittedly are rare in skilled hands), are these still less than the complications of anticoagulation or drug therapy? What really is the role of neurologic (ganglionic) inputs to the heart at supporting atrial fibrillation versus fibrous remodeling or pulmonary disease?

And while these robotics are ingenious instruments, can they really replicate the remarkable tactile feedback of the human hand and assure the safety of these uncharted waters? Will they respond as quickly to visual and tactile clues afforded by our senses at the patient's bedside? And where should we ablate? Do we really need such complicated and expensive machinery before more basic questions are answered?

Certainly the FDA has approved these devices as safe. But this does not guarentee improvements in ablation efficacy. These early approvals to little to reassure those of us in the day-to-day clinical grind of these devices' cost effectiveness. For instance, despite all of the testing in human volunteers of the magnetically-driven system by Stereotaxis, I was left to wonder how this system was approved with its propensity to developing large char formation compared to more conventional approaches. Was this not seen in earlier trials? Didn't this affect the movement of their catheter as it welded to the left atrial surface? Wasn't this considered important? How much additional time did correcting these problems add to the procedure?

Perhaps in the end it won’t matter. Perhaps the ablation lesion sets during atrial fibrillation ablation procedures will be so defined so accurately through brute force trial-and-error that we will simply push a button and, like a car wash, a catheter will be dragged through a pre-defined course that’s the same for everyone and everyone's atrial fibrillation will be magically cured. As if everyone's atrium was the same size and shape.

But then again, maybe before buying our "Mercedes," we should first look to see if we need a boat instead.

-Wes

Heart Rhythm 2007: Recapitulating

Now that the Heart Rhythm Society meeting in Denver, CO is nearing its' close, it’s time to reflect on this year’s meeting.

As always, it’s nice to see old friends and colleagues, especially other folks I trained with many years ago. Denver, too, seemed to have been placed on its best weather behavior for the meeting – it was beautiful all week. The hotel and city life seemed acceptable to most of the folks I spoke with. There were some great posters and abstract presentations, and overall, I think the meeting was well-received.

Unlike prior years though, there seemed to be little “buzz” about implantable devices like pacemakers and defibrillators (except for perhaps the iPod story) – no doubt the Big Three wanted to keep their noses clean to let the recall dust settle a bit more. And there was little new “buzz” about catheter ablation of atrial fibrillation – it seemed to be more of the same – except for revealing new “guidelines” for a procedure whose method, safety, and efficacy are still a work in progress. If there was any area that generated any new "buzz," at all, most seemed to focus on the mapping systems and robotics. At least until potential customers heard about Hansen Medical’s robotic price tag of about $650,000 or an even heftier price tag for the Sterotaxis robotic system installation for over a million dollars. Enthusiasm waned a bit then.

But there was also something else different about this meeting. It was almost imperceptible. It was insidious. There was a tacit sensation throughout the meeting.

What was it?

People were so polite.

Everyone was on their best behavior throughout the meeting. Pleasantries were shared with polite smiles and handshakes. Invitees to the Afib Summit thanked the co-chairs profusely for allowing them to be invited to the meeting, then went about their way telling their story, their pitch. Some reviewed studies and presented data well, others presented experiences or techniques rather than data, but they all pitched. Whether it was the greatest way to perform ablation, or the next block-buster drug to look for, they told their story.

And no one said a word. They were too busy being polite. Oh sure, there were many, many topics covered, and even a few oral abstract presentations with brief periods of rebuttal in small rooms, but the biggest venues were reserved for platitudes and anecdotes. Only at the end of the Afib Summit, when the invitees were discussion the “state of the art” regarding atrial fibrillation ablation was there a hint of concern that perhaps we were at risk of overstating our success rates with atrial fibrillation ablation as a profession, and risking our credibility with our referring doctors and patients. Just when it started to get juicy, the Summit ended.

Maybe it was the fact that corporate people or analysts outnumbered doctors about three to one (I’m guessing, but that’s how it seemed). Many fewer doctors appeared at this meeting than I remembered in prior years, especially doctors from overseas (could the geography of Denver played a role? I don’t know.) Perhaps that’s why most people were polite – they were on their best corporate behavior.

I remember prior meetings when abstracts would be presented in huge auditoriums and tons of microphones would line the aisles of the large amphitheater and people would get up to rebut a study’s findings or review how they had done the same study 18 years ago, and skewer the poor sole on the podium. Politeness was out. Scientific rigor was in. People were not afraid to make their opinion known. Quality and limitations of studies quickly became apparent to all. Reputations were made by thoughtful intellectual commentary, rather than strictly the number of cases performed.

Instead, attendees this year were greeted to carefully staged sets for the speakers, with plenty of nice lighting and special effects, and no forum for lively discourse, all seemingly to calm the sole and remind folks to be polite.

After all, we wouldn’t want the corporate sponsors to get upset.

-Wes

Heart Rhythm Society: Afib Summit - Day 1

The Atrial Fibrillation Summit held as part of the Heart Rhythm Society’s annual meeting in Denver, Colorado has just concluded. Why a "summit" would be held in the basement of the Colorado Convention Center seems a bit odd, but perhaps it was to be sure the fancy colored lights behind the speaker’s podium radiated a professional glow.

The event was a virtual “Who’s Who” of catheter ablation, assembled by the two program coordinators, Douglas Packer, MD of the Mayo Clinic, and Hugh Calkins, MD of Johns Hopkins Medical Center.

Eric Prystowsky, MD kicked off the sessions with a great review of the history of atrial fibrillation: its mechanisms and early historical observations by scientists of an earlier era, and put us in our place after demonstrating that most things we know seem to have already been observed by prior electrophysiologic minds from the 1940’s. He also hinted at a work published in Nature 2001 Vol 409 regarding a tarantula peptide that can reduce atrial stretch, and might be a pharmacologic target for reducing atrial fibrillation. Hmmm. But his most important message to those performing atrial fibrillation ablation procedures at the close of his talk was: “PRESERVE THE BRAIN.” Wise man.

Jose Jalife, MD (SUNY, NY) then followed with some elegant videos of his work on tissue cultured atrial cells interspersed with varying amounts of fibroblasts (that make fibrous tissue) and showed how fibrosis within the atrial architecture can contribute to the development of the erratic activations of the atrium, and that fibrosis increases in the settings of hypertension and heart failure.

Peng-Sheng Chen, MD (Krannert Institute, Indianapolis) was supposed to talk on Neural Networks in the generation and treatment of atrial fibrillation, but the message must have gotten out about his thick accent, so we never heard from him. Shin-Ann Chen, MD (Taipei) took over instead and reviewed nice basic scientific work on the contribution of atrial stretch causing atrial after-depolarizations, and might account why the initiation of atrial fibrillation always occurs after a pause and then a sinus beat, then atrial fibrillation.

Virend Somers, MD (Mayo Clinic) did a great job reviewing the mechanisms of why obstructive sleep apnea might exacerbate atrial fibrillation (or might even be a cause it) but cautioned his theories were only based on observational studies and not based on prospective studies. However, the mechanisms postulated were: low oxygen periods (hypoxemia), sympathetic activation, extreme blood pressure surges, transmural pressure gradients (see my prior post) as much as -40 to -80 mmHg during attempts to breath against a closed airway, and systemic inflammation with elevated C-reactive protein levels. Treated sleep apnea (with CPAP) had a 50% reduction in recurrent afib after cardioversion compared to folks who refused or could not tolerate the CPAP machine.

Patrick Ellinor, MD, PhD from Mass General reviewed the genetics of atrial fibrillation. He said something about the long arm of chromosome 10, but then I fell asleep briefly. I’m told he did a good job reviewing this.

After resuscitation with a coffe break, the late morning session kicked off with Michel Haissaguerre, MD (Bordeaux, France) reviewing his step-wise approach to atrial fibrillation.

Carlo Pappone, MD followed with his “Milan (Italy) Approach” to atrial fibrillation – which basically seemed to be that he ablates a lot more than he used to, because, truth be told, he’s had some recurrences. (Who knew!). He ended his discussion remarking that one patient that had chronic atrial fibrillation took him three procedures and a total procedure of 20 hours to render him afib-free, suggesting we still need better tools to approach this population. It was the first time I heard him speak to reality, and it was appreciated.

Warren (Sonny) Jackman, MD (Oklahoma City, OK) then spoke eloquently on the topic of the importance of the vagal ganglionic plexi (nerve inputs) at supporting afib, and demonstrated that stimulating one ganglionic plexus on one side of the heart could cause a pulmonary vein on the opposite side of the heart to increase its firing frequency, suggesting that afferent and efferent limbs of the vagus nerve are at play in maintaining atrial fibrillation. Brilliant work and magnificent observation. I’m just glad I’m not his fellow, because I can’t imaging how long his procedures must last when collecting this information!

Koonlawee Nadamanee, MD (Inglewood, CA) then demonstrated his results with catheter ablation targeting just the small (0.05-0.12mV) electrograms that last between 50 and 120 msec WITHOUT isolating the pulmonary veins. His data suggested about the same outcomes as others, but also showed that sometimes waiting as long as 6 -12 months might be needed to rid a patient of atrial fibrillation after his procedure in some patients. I didn’t see too many other people using solely this approach, but more seem to be incorporating some of his lesion sets.

The afternoon session was mainly made up of reviews of left atrial anatomy, by Siew Yen Ho, PhD (London, UK), followed by the new imaging and robotic techniques used for catheter ablation.

Douglas Packer, MD (Mayo Clinic) listed his pros and cons of the Stereotaxis and Hansen Robotic systems. It seems all of the current robotics suffer from an inability to reliably register anatomic locations from one imaging modality to another imaging or robotic modality. Much work needs to be done here. Bottom line: Stereotaxis had better image integration with 3D electroanatomical mapping systems, but Hansen was less expensive, portable, and could use any catheter, but limited by a slightly higher perforation risk. Some interesting data there: it seems 10-20 grams of force on the ablation catheter gave the best lesions in dogs while limiting performations.

Henry Halperin, MD (Johns Hopkins, MD) spoke to the use of real-time MR for ablating tissue and its benefits for reducing ionizing radiation and spoke to its utility at being able to see lesions in the myocardium. David Haines, MD asked at the end of the session about the resolution of 1.5Telsa MRI scanners, to which is was admitted that the 3-5mm resolution might not be enough to see left atrial walls that are only 2 mm thick in places. Henry seems to think that 3 Telsa MR scanners might improve on this. But the cost???

Vivek Reddy, MD showed some interesting work on rotational CT imaging performed during an AF ablation procedure and uses one fifth the amount for fluoroscopy to image the left atrium compared to spiral CT’s obtained pre-procedure. He also showed how these 3D volumes could then be projected onto fluoroscopic images to better localize the ablation catheter intra-operatively. Kind of cool.

The remainder of the afternoon was spent talling about the possible complications of atrial fibrillation procedures. Tamponande, gastroparesis and pyloric spasm, lasso entrapment, and minimizing embolic events with anticoagulation were all covered by Dr. Dipen Shah, MD. Esophageal perforations, heralded by chest pain, dysphagia (difficulty swallowing) and fever, were nicely reviewed by Dr. John Day, MD (Salt Lake City, UT). It seems they had two back in 2004 after ablating the posterior left atrium with an 8mm tipped catheter at 70W output for 20 seconds with each burn. Each patient presented 2-3 weeks after the (initially) uncomplicated procedure. The first died (we were left to assume) because the diagnosis was not recognized early. The other was treated aggressively with esophageal stenting, broad spectrum antibiotics (including antifungals) and nasogastric tube feedings, and survived, and has been followed 3 years and is still doing well.

Frank Marchlinski, MD (Philadelphia, PA) reviewed management of pulmonary vein stenosis, pericardial tamponde, and the phrenic nerves, and Samuel Asirvatham, MD (Mayo Clinic, Rochester, MN) help cap the anatomical relationships that can lead to these complications.

Whew! Lots covered on Day 1. Now off to poster sessions…

-Wes