Interview with Michele Straube on Results of Survey of A-Fib Patients and Wearable Devices
by Steve S. Ryan
We are happy share the results of Michele Straube’s survey of A-Fib patients on consumer wearable/portable devices/apps which many of you participated in April 2019. She received a great response―315 replies! You can review the actual survey and tabulated results at: Survey Questions and the Results.
You may want to re-read Michele Straube’s 2010 A-Fib story, Cured after 30 years in A-Fib. She recently had a second catheter ablation June 11, 2020 and is doing fine, “Went for a walk in the mountains yesterday with 500’ elevation gain, and felt good.”

Michele Straube
Interpreting the Survey Data
I asked Ms. Straube to share her insights and conclusions about her survey data and how it might or should affect A-Fib treatment strategies.
“What do you think is important in your survey’s responses?”
It’s important how many people responded, and the fact that these AFib patients are very interested in having data about their condition.
It’s clear that AFib patients are interested in being an active part of the team managing their condition. Doctors should welcome this (but see below).
For device and apps developers: there’s a huge market for wearables with apps that help inform AFib patients and gain peace of mind when making treatment decisions. Current devices don’t necessarily give us all the information we’re seeking.
There should be greater collaboration between the device developers and patients in future research and design.
“What information were you looking for?”
I wanted to know if AFib patients use wearable devices? And if so, why and how they use the data. What device or apps would they like someone to design for them.
“Were you surprised by any of the results?”
I was surprised how many different devices there are that give some kind of relevant data (over 45 different brands), yet virtually none of the A-Fib respondents were 100% satisfied with their device’s capabilities.
About 10% of the respondents said that their doctors were not interested in seeing the data from wearable devices!!!
Many of the respondents wished for device capabilities that already exist; i.e., the devices are not being marketed to the right audience.
“What results do you think should be published?”
I wanted to know how AFib patients currently use the data available and what they wish would be developed.
“How do you think your results should influence A-Fib treatment strategies?”
Educate: AFib patients should be educated about the various types of consumer devices and encouraged to use them to help manage their AFib.
Medical providers: doctors should welcome this independently collected additional data (especially for patients who experience AFib episodes when they’re not in the doctor’s office).
Treatment costs: A patient’s use of wearables and apps can reduce the overall expense of AFib treatment.
Michele shared how she used a wearable device:
Using myself as an example, I take an ECG reading on my device, email it to the doctor’s office, and we discuss what to do about a “bad” reading via email or phone.
The one time my device was not working correctly, I had to go into the office for an official EKG reading, which took up much more of everyone’s time and cost oodles of money … and the end result (modification of my meds) was the exact same had I emailed a reading from my device.
We appreciate Michele’s survey work and sharing the results and her conclusions with A-Fib.com readers.
Review the actual survey and tabulated results at: Survey Questions and the Results.
Michele expressed her gratitude to all who participated in this survey, and to A-Fib.com and other sites that solicited A-Fib patients to take the survey. Michele Straube can be reached at mstraube@mindspring.com
Results of Survey of A-Fib Patients and Wearable Devices

Michele Straube
In the spring of 2019, Michele Straube (who was cured of her A-Fib in 2010), conducted a survey of A-Fib patients about consumer wearable technology and apps designed to collect and share a patient’s cardiac data in real-time. The survey was completed by 315 A-Fib patients.
Read our interview with Michele in August 2020 who shares her insights and conclusions about the survey data.
Results of Survey of A-Fib Patients and Wearable Devices
Q1 The Survey Introduction; completed surveys: 315
Q2: Which type of AFib do you suffer from?
- Paroxysmal (>55% — more than half)
- Persistent (~13%)
- Permanent (~8%)
- No longer in AFib (~15%)
- Other (~7%, variations on the above themes)
Q3: How long have you been diagnosed with AFib?
- Less than 1 year (10%)
- 1-2 years (~22%)
- 3-5 years (~25%)
- More than 5 years (~39%, plus ~4% other)
Q4: Do you regularly use any of these wearable/portable devices/apps to provide you with AFib-related information?
- Handheld (portable) ECG/EKG monitor (~47% — almost half)
- Wristband HR monitor (~32%)
- Wristband ECG/EKG monitor (~15%)
- Lead- and wire-free event monitor (~3%)
- No, don’t use any devices (~13%)
- Other (15%) – BP monitor, implanted loop monitor, pacemaker, etc.
Q5: Brands
- Alivecor/Kardia: 150 (almost half)
- Apple Watch (some version): 62 (20%)
- Fitbit/Garmin (some version) 56 (~19%)
- Ziopatch: 6 (~2%)
- Others: ~40 other separate brands
Q6: What made you decide to regularly use the wearable/portable device/app?
- Prescribed by my doctor (~10%)
- Personal decision (~73%)
- Be informed / peace of mind / decide about meds (101, one-third)
- ID “silent” AF episodes / document AFib to doctor when not in office (60, 20%)
- Reduce ER visits / decide whether to contact doctor (24, ~8%)
- Prevent overdoing it during exercise (18, ~6%)
Q7: If you do use a device/app, which AFib-related information do you find valuable?
- HR – instantaneous reading (~75%)
- Heart rhythm (~71%)
- HR – trends over time (~48%)
- ECG/EKG (~44%)
- HR variability (~35%)
- Sleep data (from CPAP and other device) (~30%)
- BP (20%)
- Oxygen saturation (10%)
Q8: Does having AFib-related information from your device/app change your behavior? How?
- No, does not change behavior (100, almost one-third)
- Yes, does change behavior (a little over two-third)
- Actions to end/prevent AFib (85, ~28%)
- “Emotional comfort blanket” / reduced anxiety (45, ~15%)
- Modify meds (24, ~8%)
- How fast to get to ER, contact doctor (14, ~5%)
- Makes me panic / become obsessed with HR (7, ~2.5%)
Q9: Do you share any of the data with your doctor? How? What does doctor do with it?
- Yes: 177 (more than half)
- No: 87 (~30%)
- What share?
- Rhythm strip (108, one-third)
- HR trends / HR spikes (21 (~7%)
- times / length in AFib (20, ~7%)
- Summaries / trends (14, ~5%)
- Own charts analyzing info (8, ~3%)
- How?
- In person (93, almost one-third)
- Email (61, 20%)
- Automatic access (18, ~6%)
- What does doctor do with it?
- Diagnosed with AFib from device data (5)
- Doctor not interested (30, ~10%)
- Decide what treatment (19, ~7%)
- Pleased for additional info (15, ~5%)
Q10: Think about the AFib-related information you wish you could get from a device/app.
- What would you like someone to design for you?
- Some things asked for already exist—may need to do better education/ marketing
- ID any arrhythmia / name type of arrhythmia (51, ~16%)
- Auto/continuous AF monitoring / 24/7 event recorder (37, ~12%)
- Alert when in AFib (32, ~11%)
- Greater accuracy / fewer “possible”, “unclassified”, “indeterminate” readings (28, ~10%)
- All-in-one watch (ECG/EKG, HR, HRV, BP, oximeter, sleep) (20, ~7%)
- Less bulky, cheaper, easier to read (18, ~6%)
- Greater patient access to device data / automatic interpretation / show trends (18, ~6%)
- How would this feature/information improve your quality of life and/or change your behavior?
- Inform treatment decisions (55, ~18%)
- “Knowledge is power,” peace of mind (35, ~12%)
- Cause and effect / look for triggers, patterns (18, ~6%)
Q11: Is there anything else you’d like to share with the Heart Rhythm 2019 audience?
- Complaints about specific devices
- Have insurance cover cost of devices
- Educate doctors about the existence and value of these devices
- Power to the patient
- “Anyone with arrhythmias should be assigned one of these devices”
- “We need full access to what is happening in our bodies so we can make informed decisions and be partners in our care with doctors”
End of survey and results
Go to our interview with Michele Straube about her survey conclusions.
If you find any errors on this page, email us. Y Last updated: Thursday, August 6, 2020
2020 AF Symposium Abstract: High Hemorrhagic Risk Factors from NOACs
2020 AF Symposium Abstract
High Hemorrhagic Risk Factors from NOACs
by Steve S. Ryan

NOAC Hemorrhagic Stroke Risk
When I read in this abstract from Massachusetts General Hospital in Boston, these NOAC findings almost jumped off the page at me! We know that NOACs are high risk meds (though they are certainly better than having an A-Fib stroke). But, add to that, also a high risk of Hemorrhagic risk factors, too?
This is a most important and relevant study for A-Fib patients.
Brain MRI to Detect NOAC Hemorrhagic Stroke Risk
Researchers from Massachusetts General Hospital in Boston used MRI to identify markers of increased intracerebral hemorrhage risk (ICH).
This was a single center study conducted from January 2011 to May 2019. In the study were 282 patients of which 76% had Atrial Fibrillation; Of the 282 patients, 49 were taking NOACs and 233 were taking warfarin. All demographic variables, vascular risk factors, etc. were similar between the two groups.
Study Findings
Analyzing the MRI data of the 282 participants revealed:
• cerebral microbleeds (67%)
• moderate-to-severe white matter hyperintensities (76%)
• cortical superficial siderosis (excess iron in body tissue) (18%)
In particular, of the 49 patients taking NOACs:
• 97% had at least one of these markers
• 60% had two
• 4% had all three
Conclusion
Established MRI markers of increased ICH (intracerebral hemorrhage) were common in the NOAC study group.
High hemorrhagic risk markers were present in an overwhelming 97% of NOAC patients.
Editor’s Comments:
Does taking a NOAC long-term mean you’ll eventually develop a hemorrhagic stroke?
No, the researchers didn’t go that far. This was a limited study as the number of patients who were on NOACs was 49 compared to those on warfarin which was 233.
Red Flag Warning: But this study should raise a red flag for anyone taking NOACs long term. Almost all patients on NOACs (97% in this study) had “evidence of neuroimaging markers of high ICH risk.”
The authors recommended that prescribers (and patients) look at nonpharmacological stroke prevention methods. Eliminating the need for lifelong NOAC anticoagulation “may decrease the incidence of fatal/disabling hemorrhages in A-Fib patients.”
For more on NOACs and stroke, see my article Anticoagulants Increase Risk of Hemorrhagic-Type Strokes.
If you find any errors on this page, email us. Y Last updated: Monday, September 7, 2020
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2020 AF Symposium: Terminate Persistent A-Fib by Ablating Higher Frequency Modulation Areas
2020 AF Symposium
Terminate Persistent A-Fib by Ablating Higher Frequency Modulation Areas
by Steve S. Ryan
Background: Previous studies by Dr. Jose Jalife, University of Michigan, Ann Arbor, MI.:
• A-Fib Produces Fibrosis—Experimental and Real-World Data: Dr. Jose Jalife’s ground-breaking research studies with sheep demonstrated conclusively that A-Fib produces fibrosis;
• Experiments in Atrial Remodeling in Sheep and the Transition From Paroxysmal to Persistent A-Fib: Dr. Jalife’s later research showed how A-Fib progresses in time from paroxysmal to persistent A-Fib.

Jose Jalife MD
At this year’s AF symposium, Dr. Jalife presented findings by research colleagues showing how leading-driver regions of A-Fib have higher frequency modulation (iFM) areas which, when ablated, usually terminate persistent A-Fib.
His presentation was entitled “Using Instantaneous Amplitude and Frequency Modulation to Detect the Footprint of Stable Driver Regions as Targets for Ablation of Persistent AF.” Dr. Jose Jalife, University of Michigan, Ann Arbor, MI.
Clinical Study
Researchers have used sheep and pigs in previous studies. This time to detect rotors in sheep, researchers developed algorithms based on amplitude modulation (iAM) and frequency modulation (iFM).
They then switched to pigs who underwent high-rate atrial pacing to develop persistent A-Fib.

Frequency modulation (iFM) /instantaneous amplitude modulation (iAM) approach to patients with persistent atrial fibrillation
Using the PentaRay Catheter (Biosense Webster) to produce high-density electroanatomical atrial mapping, they found that regions of higher than surrounding average iFM were considered leading-drivers.
These iFM areas also had the highest dominant frequency. “They are the footprints of rotors.”
Not all rotors are drivers. Only those with the highest frequency and greater stability are A-Fib drivers. “IFM helps identify the regions with the highest frequency drivers.”
Researchers constructed two leading-driver + rotational-footprint maps (rotors) 2.6 hours apart from each other to test for stability and to guide ablation. Leading-driver regions remained in approximately the same spots in each map.
The trial showed high iFM areas are responsible for maintaining persistent A-Fib
Study Results
When these areas were ablated, persistent A-Fib terminated in 12 of the 13 cases (92.3%). Rotational-footprints (rotors) were found at every leading-driver region, but not all rotors had higher iFM. “In pigs, ablation of leading-driver regions usually terminates persistent A-Fib and prevents its sustainability.”
Conclusion
Dr. Jalife concluded that high iFM areas are responsible for maintaining persistent A-Fib. And using iFM results in higher sensitivity and specificity without the need for high resolution and costly panoramic mapping.
Editor’s Comments:
(I had never heard of the term “frequency modulation” (iFM) applied to A-Fib before.)
High Areas of iFM a New Discovery in A-Fib: The researchers have re-defined the field of mapping and catheter ablation.
This research shows that higher regions of iFM help identify the regions with the highest frequency drivers (rotors) and are more easily mapped in persistent A-Fib.
Dr. Jalife and his colleagues have given EPs and researchers a new tool to better ablate persistent A-Fib, the most difficult arrhythmia to fix.
If you find any errors on this page, email us. Y Last updated: Wednesday, August 26, 2020
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2020 AF Symposium: Protecting the Esophagus by Cooling It
2020 AF Symposium
Protecting the Esophagus by Cooling It

Mark Gallagher. MD
“We know that most strategies (to prevent fistula) don’t work,” Says Dr. Mark Gallagher from St. George’s University Hospital in London, United Kingdom.
At the 2020 AF Symposium, he described an innovative strategy he and his colleagues developed to prevent fistula. He presented the completed IMPACT study which investigated whether Attune Medical’s ensoETM esophageal cooling system could effectively reduce the incidence and severity of thermal injuries to the esophagus during cardiac ablation.
IMPACT Double Blind Randomised Controlled Trial
In their clinical trial, Dr. Mark Gallagher and colleagues divided 120 patients into two groups: a control group and a experimental group.
The Control Group: The control group received only standard care, in this case a temperature probe in the esophagus. If the temperature in the esophagus went too high, they would stop the ablation till the temperature went back down (current practice).
This would often lead to the EP not being able to effectively isolate all A-Fib signal areas in the heart which were too close to the esophagus. And often, by the time the temperature went up, damage had already been done to the esophagus.
The Experimental Group: Patients in the second (experimental) group instead received a 3-foot long silicone soft tube in their esophagus connected to what was basically a refrigerator. This closed loop system pumped cooled water (25 ͦ F) down one loop of the tube, then back through another loop to the console whenever the EP worked near the esophagus. The EP controls the temperature.
Double-Blind for Both Operators and Evaluators
This was a double-blind study. The EP doing the ablation didn’t know if they were working on a Control or Experimental patient. And the doctors evaluating the procedure for possible esophagus damage also were blinded.
After 7 days, an endoscopy was performed on each patient’s esophagus (an endoscopy examines the inside of an organ). They were looking for lesions and for gastroparesis (delayed emptying of the stomach).
IMPACT Study Results
The Control group who received the standard temperature probe had multiple epithelial lesions, while the Experimental group who experienced the closed loop cooling system had only one minor lesion.
The Experimental group also needed less fluoroscopy (X-ray) time. And, more importantly, the EP was able to ablate longer in areas near the esophagus (such as the posterior wall of the left atrium). That improved the success rate of the ablation and ablation efficacy.
Editor’s Comments
Most fistula patients die. And for those who live through the emergency treatment, they are often compromised for life. But with the esophageal cooling system, patients and doctors may never again have to worry about the dreaded complication Atrial-Esophageal Fistula!
Cooling the Esophagus, a Major Medical Breakthrough! Cooling the esophagus is simple and relatively easy to do. And, barring future research findings, it seems full proof.
The Attune Medical’s ensoETM esophageal cooling system is certainly cheaper than having to care for patients with a fistula.The Attune Medical ensoETM esophageal cooling system can provide both cooling during RF ablation, and heating during Cryo ablation.
Probably among the major proponents of the esophagus cooling system will be hospital administrators. Treating patients with a fistula is a huge expense and a nightmare for hospital staff.
A fistula is an all-hands-on-deck emergency involving not just the EP department but surgeons and many hospital staffers. A surgeon may have to perform emergency surgery to insert stents in the esophagus in order to close off the fistula, or the surgeon may have to cut out part of the damaged esophagus, which is particularly risky
(I remember one EP describing how he and his staff were running down a hospital corridor with their fistula patient close to dying, in order to get the patient to an operating surgeon.).
Esophageal Cooling Means Better Ablations: And as a bonus, using the esophageal cooling system enables EPs to do a more thorough better job. They can ablate all areas of the heart rather than avoiding areas too close to the esophagus or using lower power with shorter duration or less contact force.
When Will Esophageal Cooling be Available? For catheter ablation application, probably not soon. In the U.S and probably worldwide, Attune Medical’s ensoETM esophageal cooling system is already in use and approved for specific purposes, for example, in cases of brain damage where a patient needs to have their whole body cooled down. But not for catheter ablation
In the United Kingdom, it will first have to be approved by NHS. In the U.S., it may not need to go through the FDA approval process again. (But this is a very speculative observation.)
Will Ablation Centers Implement? It will probably require a great deal of marketing to make EPs and ablation centers aware of and actually start using the esophageal cooling system. And because Atrial-Esophageal Fistula is such a rare complication, centers may not be willing to invest in an esophageal cooling system.
If you find any errors on this page, email us. Y Last updated: Wednesday, August 26, 2020
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2020 AF Symposium: After Diagnosis, How Soon Should an A-Fib Patient Get an Ablation?
2020 AF Symposium
After Diagnosis, How Soon Should an A-Fib Patient Get an Ablation?
by Steve S. Ryan
When you were diagnosed with A-Fib, did your doctor say, “Let’s wait a year or two and try different drugs before we send you for a catheter ablation.” Is this attitude justified by current research?

Karl-Heinz Kuck, MD
Dr. Karl-Heinz Kuck of St. Georg Hospital in Hamburg, Germany discussed this most important topic for patients in his presentation “ATTEST Trial―Impact of Catheter Ablation on Progression from Paroxysmal to Persistent AF.”
Heavy Decision for Electrophysiologists (EPs): When to Ablate
Dr. Kuck started by describing how he personally is affected by the strategic decisions he has to make every day. As an EP, “when should we ablate a patient with A-Fib?” Should we just look at symptoms (not considering anything that is caused by A-Fib).
Will this decision contribute to a patient moving into persistent forms of A-Fib?
This happens all too often―within one year, 4% to 15% of paroxysmal A-Fib patients become persistent.
Persistent A-Fib Patients at Higher Risk
Patients who progress to persistent A-Fib are at a higher risk of dying, they have more risk of stroke, it’s more difficult to restore them to normal sinus rhythm.
In the Rocket AF trial, the mortality rate of persistent A-Fib was triple that of paroxysmal patients.
ATTEST stands for “Atrial Fibrillation progression randomized control trial“
ATTEST: RF Ablation vs Antiarrhythmic Drugs
The ATTEST clinical trial included 255 paroxysmal patients in 36 different study locations. They were older than 60 years and had to have been in A-Fib for at least 2 years (mean age 68). They had failed up to 2 antiarrhythmic drugs (either rate or rhythm control).
Patients were randomized to two groups: radiofrequency ablation (RF) (128) or antiarrhythmic drugs (127). They were followed for 3 years (ending in 2018).
ATTEST Findings: RF Ablation vs Antiarrhythmic Drugs
At 3 years, the rate of persistent A-Fib or atrial tachycardia was lower (2.4% ) in the RF group vs the antiarrhythmic drug group (17.5%).
The RF group was approximately 10 times less likely to develop persistent A-Fib compared to the antiarrhythmic drug group.
For patients in the antiarrhythmic drug group, 20.6% progressed to persistent A-Fib or atrial tachycardia compared to only 2.2% in the RF group.
Recurrences occurred in 49% of the ablation group vs. 84% in the drug group. Repeat ablations were done on 17.1% of the ablation group.
Dr. Kuck’s Conclusion
Early radiofrequency ablation was superior to antiarrhythmic drugs to delay the progression to persistent atrial fibrillation among patients with paroxysmal A-Fib.
His advice: “Ablate as early as possible.”
Editor’s Comments
Don’t Leave Someone in A-Fib―Ablate as Early as Possible: Dr. Kuck’s ingenious research answers once and for all whether or not A-Fib patients should be left in A-Fib, whether seriously symptomatic or not (e.g., leaving A-Fib patients on rate control drugs but still in A-Fib.)
These patients are 10 times more likely to progress to persistent A-Fib. That’s why today’s Management of A-Fib Guidelines list catheter ablation as a first-line choice. That is, A-Fib patients have the option of going directly to a catheter ablation.
Know Your Rights—Be Assertive: I occasionally hear of Cardiologists who refuse to refer patients for a catheter ablation, who tell patients a catheter ablation is unproven and dangerous.
When you hear something like that, it’s time to get a second opinion and/or change doctors.
As an A-Fib patient, you should know your rights and be assertive—that according to the guidelines, you have a right to choose catheter ablation as your first choice.
Your doctor may try to talk you into first trying antiarrhythmic meds before offering you the option of a catheter ablation. That is so wrong!
Why risk progressing into persistent A-Fib? There are so many bad things that can happen to you when left in A-Fib. As Dr. Kuck points out, you’re at a higher risk of dying, there’s more risk of stroke, it’s more difficult to restore you to sinus.
And we haven’t even talked about heart damage from fibrosis, the risk of electrical remodeling of the heart and, the all-too-real dangers of taking antiarrhythmic drugs over time.
Thanks for Sharing, Dr. Kuck! I am particularly grateful to Dr. Kuck for sharing his own anxieties and decision-making strategies when trying to determine when a patient should get a catheter ablation, how this affects him personally.
Making decisions about patients whom one cares about isn’t always easy. But Dr. Kuck’s research should now make these decisions easier both for EPs and for patients.
The Bottom Line for Patients: It’s safer to have an ablation than to not have one. For more see my article Live Longer―Have a Catheter Ablation!
If you find any errors on this page, email us. Y Last updated: Wednesday, August 26, 2020
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2020 AF Symposium Live Case: Ultra-Low Temperature Cryoablation
AF Symposium 2020
Live Case: Ultra-Low Temperature Cryoablation
Background: The Adagio Medical iCLAS catheter is a Cryo catheter that uses ultra-low temperatures and is unlike anything currently on the market. To learn more about the iCLAS catheter, see my earlier report from the 2018 AF Symposium: Innovative iCLAS Cyro Catheter by Adagio Medical.
Note: The Adagio Medical iCLAS is not yet FDA approved. The U.S. IDE study trial is active and enrolling. The clinical trial started in December 2019. https://clinicaltrials.gov/ct2/show/NCT04061603.
Live Ablation Via Streaming Video

Tom DePottee, MD
Live from Belgium, Dr. Tom De Potter and his colleagues from OLV Hospital performed an ablation using Adagio Medical’s ultra-low temperature cryoablation catheter.
When the Symposium audience joined the live ablation via streaming video, Dr. De Potter and his colleagues had already performed a single transseptal puncture and were working in the left atrium.

Several catheter configurations possible with the Adagio Medical system.
To produce temperatures as low as (minus) –196° Celsius, Adagio Medical uses what they call Near Critical Nitrogen (NCN) which is far lower than current CryoBalloon technologies.
Producing Continuous Linear Ablations
Adagio catheters produce continuous linear ablations and can also be configured to do focal (single point) catheter lesions. Dr. De Potter also showed how the same Adagio Medical catheter can also do cryo mapping.
As we watched, Dr. De Potter encircled the Left Superior Pulmonary Vein (PV) with a double loop catheter. Then applied the cryo energy and froze the ostium area to isolate the PV. The catheter stylus included a loop of the freezing section and a loop with electrodes which recorded/mapped the A-Fib signals.
Freezing Isolated the Vein
We could see the ice formation on the catheter itself and how the freezing isolated the vein.

Adagio catheter encircles PV and freezes to isolate the PV area.
It only took 30 seconds to isolate that vein, but Dr. De Potter continued the freeze for one minute. Then performed what he called a bonus freeze.
On the catheter monitor, we could see how that vein had PV potentials which were then isolated.
Then Dr. De Potter moved to the Right Pulmonary Veins. The phrenic nerve usually runs close to the ostia of the right PVs. He said they perform phrenic nerve pacing to prevent damage to the phrenic nerve. We saw how they performed phrenic nerve capture.
Monitoring the Phrenic Nerve
If they do find they might be damaging the phrenic nerve, they don’t ablate there or insert a different catheter stylus configuration which doesn’t affect that area.
They didn’t achieve isolation of the Right Interior PV, so they did a second ablation while slightly changing the stylus loop position. Dr. De Potter said that he usually achieves isolation with one pass, except for, as in this case, with the Right Interior PV which is more challenging.

Protecting the esophagus with the Adagio Medical Warming Balloon (right of heart)
CryoAblation is Reversible. Dr. De Potter showed how they first used low energy cryo in a 30 second ablation to see if the phrenic nerve was affected (if affected, the tissue can be de-frosted and returned to normal or reversed.) Then they applied the full cryo energy at the ultra-low temperature which is permanent. The speed of decrease in cooling is very fast at 300°C/sec.
Protecting the Esophagus
To protect the esophagus, Dr. De Potter showed how they insert a warming balloon with constantly circulating warm saline into the esophagus which prevents excessive cooling and damage to the esophagus.
He stated that the next generation of the warming balloon will also have temperature sensing. They can then have a much better idea of what the freezing will do to the esophagus, how much temperature affects will be seen in the esophagus.
Ablating the Posterior Wall
Dr. De Potter also showed the Adagio Medical system ablating the posterior wall. “It’s very simple. We will make overlapping rings.”
We saw him make those overlapping ring ablations in three passes which blocked conduction over the posterior wall. But with a larger atria, he may use 6 applications. He mentioned that at this stage he hasn’t achieved consistent success making a Mitral Isthmus line.
The Key Benefit of Ultra-Low Temperature Cryoablation
According to Dr. De Potter:
“The key benefit of this technology is a different energy source in contrast to the CryoBalloon which uses a theoretical minimum of –80°C.
This system (Adagio Medical) uses liquid nitrogen which has a theoretical minimum of –196°C. When you consider that this –80°C is at the center of the balloon and not necessarily at the tissue, we think we have a far better margin for efficient energy delivery while providing for patient safety.”
Editor’s Comments:
When I visited the Adagio booth at the Symposium exhibit hall, I was fascinated to see how easily the catheter can be manipulated into many different configurations depending on the lesions which need to be made.
Using its full length, the catheter can produce ultra-low temperatures along its whole span (110mm). Its 20 electrodes can also produce cryo-mapping of the atria.
Why is the iCLAS Cryo catheter special and innovative? The iCLAS catheter produces ablation lesions like current CryoBalloon catheters but at lower temperatures (colder). One would expect that such ultra-low Cryo lesions would be deeper, more transmural, and more lasting.
In addition, the ability to produce unlimited shapes gives the iCLAS catheter a unique ability to position Cryo lesions in a variety of locations in the heart.
The Adagio Medical iCLAS cyro system will make ablations much simpler and easier for EPs. It may eventually supersede normal CryoBalloon ablation (which is already a very effective ablation strategy).
If you find any errors on this page, email us. Y Last updated: Saturday, May 23, 2020
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2020 AF Symposium Abstract: Using MRI to Check Pulsed Field Ablations (PFA)
2020 AF Symposium Abstract
Using MRI to Check Pulsed Field Ablations (PFA)
by Steve S. Ryan
Background: Pulsed Field Ablation (PFA) is a new treatment for Atrial Fibrillation with some unique features. First, the ablations are tissue-specific, only affecting heart tissue and not the surrounding organs. Second, instead of direct contact to make lesions, as with RF ablation, all that’s necessary is proximity to the targeted tissue to make the ablation.

Pierre Jaïs, MD, The Bordeaux Group
In a remarkable statement that would strike terror in the heart of most Electrophysiologists (EPs), the French Bordeaux group stated about Pulsed Field Ablations:
“Measures to alter lesion placement based on proximity of the esophagus and phrenic nerve were not taken.”
Normally, during a RF or cryo ablation, doctors move the esophagus as far away as possible from where they are ablating. In this study they took no such precautions.
Pulsed Field Ablation (PFA) study

Farapulse catheter – Five Petal Flower configuration
At this year’s AF Symposium, the French Bordeaux group presented an abstract of their study using Pulsed Field Ablation (PFA) with MRI.
Study Technique: With the Pulsed Field Ablation (PFA) waveform generator, they used a 5-spline 12F catheter to isolate the Pulmonary Veins (PVs). Then, they used MRI to check the PFA lesions to assess any extra-cardiac damage.
Study Results
NO DAMAGE TO THE ESOPHAGUS

Position of Esophagus behind the heart
In 17 patients, the esophagus was located directly behind and adjacent to PFA lesions at a distance of 0.5 to 2 mm. Post PFA ablation and using MRI imaging, they found no esophageal lesions.
They also found no discontinuities (gaps) in any isolated PV.
(With other energy ablation sources such as RF, the esophagus would be scarred, have ulcer-like damage, and fistula.)
NO PHRENIC NERVE DAMAGE

Phrenic nerve near heart
When they ablated the right PVs, they knew that they were right next to or close to the phrenic nerve.
Upon examination, PFA lesions were found in the area of the phrenic nerve but no damage was seen (despite the fact that there was consistent phrenic nerve capture during PFA delivery).
LESS THAN 60 SECONDS PER PATIENT
And even more remarkably, the total energy delivery time per patient was less than 60 seconds. This is much less time than with other types of ablation.
Editor’s Comments:
I expect Pulsed Field Ablation (PFA) will revolutionize catheter ablation for A-Fib. This is incredibly good news for patients and will make the EP’s job much easier requiring less time in the EP lab.
Better for Patients
Atrial-Esophageal Fistula No Longer a Threat: These are remarkable results! When using Pulsed Field Ablation (PFA), EPs don’t have to worry about damaging the esophagus, even though the PFA catheter may be very close to the esophagus. The dreaded complication Atrial-Esophageal Fistula will become a thing of the past! The same holds for Phrenic Nerve damage.
PFA is Tissue Selective: Instead of direct tissue contact as with RF ablation, all that’s necessary with PFA is to position the catheter in proximity to the targeted tissue. Because PFA is tissue selective, it’s easier and faster to make lesions without gaps.
Better for EPs
PFA Allows More A-Fib Patients to be Treated: Because PFA takes so little time, patients won’t have to wait for months to schedule an ablation. EPs will be better able to handle today’s epidemic of A-Fib cases. (One wonders how many PFA ablations a skilled EP will be able to do during a day?)
Better for Health of EPs: PFA may add years to an EP’s career and health. EPs no longer will have to wear those heavy lead shields for long periods of time to prevent fluoroscopy radiation damage.
But Not Ready Yet
It will probably take 3-5 years for PFA to be available for most A-Fib patients.
If you find any errors on this page, email us. Y Last updated: Wednesday, August 26, 2020
Return to 2020 AF Symposium Reports
COVID-19: White House Pushes Unproven Drugs—Risk of Arrhythmias and Sudden Death
by Steve S. Ryan
Note: I have already written about the risk of COVID-19 for patients with A-Fib (and other cardiovascular diseases). See my post: COVID-19 Virus: Higher Risk for A-Fib Patients.
In recent coronavirus pandemic press conferences, President Donald Trump has repeatedly advocated the use of the drugs hydroxychloroquine (HCQ) and azithromycin (Z-Pak) to treat the COVID-19 virus.
He often says, “What have you got to lose?” About treating patients, he also said these drugs can “help them, but it’s not going to hurt them.” (Really?)
Hydroxychloroquine & Azithromycin Danger―“What Have You Got to Lose?”
The drugs hydroxychloroquine and azithromycin are currently gaining attention as potential treatments for COVID-19. Hydroxychloroquine sulphate (Plaquenil) is an antimalarial medication. Azithromycin (Z-Pak) is an antibiotic. (Antibiotics in general are ineffective against viruses.)
Each has potential serious implications for people with existing cardiovascular disease.
Contrary to Mr. Trump’s statements, you do have a lot to lose. Medical groups warn that it’s dangerous to be hawking unproven remedies.
Recently, three U.S. heart societies published a joint statement to detail critical cardiovascular considerations in the use of hydroxychloroquine and azithromycin for the treatment of COVID-19.
According to the “Guidance from the American Heart Association, the American College of Cardiology and the Heart Rhythm Society”:
Complications include severe electrical irregularities in the heart such as arrythmia (irregular heartbeat), polymorphic ventricular tachycardia (including Torsade de Pointes) and long QT syndrome, and increased risk of sudden death.
The effect on QT or arrhythmia of these two medications combined has not been studied.
With these increased dangers in mind, we must not take unnecessary (or foolish) risks in the rush to find a treatment or cure for COVID-19.
What We Know So Far About These Drugs and COVID-19
COVID-19 Virus: Higher Risk for A-Fib Patients
COVID-19, the disease caused by the new coronavirus SARS-CoV-2, has sickened hundreds of thousands and continues to kill large numbers of people worldwide.
Typically, it’s considered a threat to the lungs, but COVID-19 also presents a significant threat to heart health, according to recently published research.
“But It’s Just the Flu, Right?”
“During most flu epidemics, more people die of heart problems than respiratory issues like pneumonia,” according to Dr. Mohammad Madjid, McGovern Medical School at UTHealth. He expects similar cardiac problems among severe COVID-19 cases.
In addition, COVID-19 can worsen existing cardiovascular disease. For example, Atrial Fibrillation patients may develop myocarditis, an inflammation of the heart muscle. If left untreated, myocarditis may lead to symptoms of heart failure.
And for otherwise healthy people, COVID-19 can cause new heart problems.
Comorbid Conditions Increase Fatality Rate
Many A-Fib patients also suffer from other chronic conditions such as diabetes and hypertension. With comorbid conditions, COVID-19 can increase the severity and fatality of the virus.
According to research from the Chinese Center for Disease Control and Prevention (CCDC), COVID-19 patients from mainland China who reported no comorbid conditions had a case fatality rate of 0.9%.
While patients with the following comorbid conditions had much higher rates:
+ 10.5% for those with cardiovascular disease
+ 7.3% for diabetes
+ 6.3% for chronic respiratory disease
+ 6.0% for hypertension
+ 5.6% for cancer.
Among critical cases, the case fatality rate is unsurprisingly highest at 49%.
Take Away: A-Fib Patients at Higher Risk for COVID-19
Patients with underlying cardiovascular disease (i.e., A-Fib) are at higher risk for developing COVID-19 and have a worse outlook. Prior heart disease is a risk factor for higher mortality from COVID-19. Cardiovascular patients are encouraged to take additional, reasonable precautions to avoid contact with the COVID-19 virus. And to stay current with vaccinations, especially for influenza and pneumonia. Since people can spread the COVID-19 virus before they know they are sick, it is important to stay away from others when possible, even if you or they have no symptoms. • Stay at least 6 feet (2 meters) from other people Social distancing is especially important for people who are at higher risk of getting very sick including older adults and people of any age who have serious underlying medical conditions. For more information: see the article “How to Protect Yourself & Others” from the Centers for Disease Control and Prevention (CDC).A-Fib Patients: Practice Social Distancing and Stay Safe at Home
• Do not gather in groups
• Stay out of crowded places and avoid mass gatherings