Utilizing the EnSite Precision™ Cardiac Mapping System and Assurity MRI™ Pacemaker: Interview with David N. Kenigsberg, MD

In this feature interview, EP Lab Digest speaks with David N. Kenigsberg, MD from Florida Heart Rhythm Specialists in Ft. Lauderdale, Florida, about his use of the EnSite Precision™ Cardiac Mapping System and Assurity MRI™ Pacemaker (St. Jude Medical, an Abbott Company). 

What do you think are the key features of the EnSite Precision Cardiac Mapping System? Has this technology met or exceeded your expectations? 

The major difference between this and the previous system is that the EnSite Precision System is more rapid at acquiring activation and location points, and it is more accurate at doing so as well. On average, I am acquiring over 3,000 points in less than 10 minutes. 

The addition of the magnetic platform has markedly improved the model and map creation in this version, in that the system will not accept or throw out data points that are not accurate. Thus, if I’m not making adequate contact with the tissue or the signal is noisy, the points will be discarded. This saves a lot of time due to the automation of the point acquisition and the fidelity of the information gathered. 

The EnSite Precision Cardiac Mapping System is a 3D electroanatomical mapping system that has exceeded my expectations. I have been using 3D electroanatomical mapping since I started my EP fellowship at Medical College of Virginia/Virginia Commonwealth University in 2005. Mapping technology has consistently gotten better over time, with new upgrades and improved technologies. But for me, this technology is what I consider to be a game changer, and the reason is I’m able to be more efficient with the use of my time. The AutoMap feature allows me to tackle more arrhythmias in an individual patient in less time because of the improvement in mapping. For example, if a patient has atrial fibrillation, atrial tachycardia, and atrial flutter, my previous approach would be to do a pulmonary vein isolation (PVI) for the atrial fibrillation, and then bring the patient back at a later date to address the other arrhythmias. With this system, due to the rapidity of the AutoMap function, with which I can gather the data and its improved accuracy, I can typically tackle all the arrhythmias that present in the same setting. Patient satisfaction as well as the effectiveness and safety of the procedure have all been improved. 

How many and what kinds of cases have you performed with the EnSite Precision Cardiac Mapping System?

I think we’ve treated in excess of 50 patients thus far. I’ve been using the system since the beginning of this year. I address complex arrhythmias such as atrial fibrillation, atrial tachycardia, atypical flutter, ventricular tachycardia (both idiopathic VT and ischemic reentrant VT), and PVCs (both idiopathic and structural). 

What attracted you to start using the EnSite Precision Cardiac Mapping System?

I have been using EnSite™ systems in my lab since 2007, and we’ve been periodically getting upgrades. When I heard about this software and the upgrades that were going to be available, I petitioned my hospital, as well as my local sales rep and her manager, to be one of the first to trial this system. I was the first in the state of Florida to utilize it, and to date, I have probably the largest clinical single-user volume with this system so far. 

Has the system helped you to achieve successful results? Could you discuss an example case? 

I recently treated a patient with a persistent atrial arrhythmia. On the surface ECG, it looked to be an atypical atrial flutter. The patient had never had an ablation, and had a history of atrial fibrillation. They were highly symptomatic, and had failed multiple antiarrhythmic drugs and cardioversions. The patient was transferred to me from another hospital, specifically for an ablation. The patient had a PVI followed by an ablation of a mitral isthmus atrial flutter, followed by an ablation of 2 distinct left atrial tachycardias, followed by atypical atrial flutter ablation all in one procedure. The entire procedure took 3 and a half hours, and during the mapping, we were able to rapidly gather different maps after each rhythm change. When we went from the atypical mitral isthmus flutter to the left atrial tachycardia, we remapped using the TurboMap feature (we did that again for the second left atrial tachycardia), and then did that again for the atrial flutter. All of the maps had over 2000 points, and took only 5 to 10 minutes to acquire. Therefore, because of this system, I was able to tackle 5 distinct arrhythmias, perform a complex procedure in a very short period of time, and achieve success. I was able to ablate the patient, and during ablation, the patient went into sinus rhythm. It was a great result for the patient and satisfying for me, the operator.  

Why is automation important in the diagnosis and delivery of therapy in EP procedures? How does the EnSite Precision Cardiac Mapping System help you achieve this?

The EnSite Precision system, with AutoMap software, is able to throw out points that are not accurate, based on criteria I have previously set up, whereas before, the system operator would do that manually; it was a very time-consuming and personnel-driven process. Now it’s an automated process — the computer is able to determine if the points are accurate and if they should be accepted. Therefore, it has made the process much faster and more streamlined. The accuracy of the detection algorithm is very good and does not require much if any post-mapping editing.

How precise is the EnSite Precision Cardiac Mapping System with the addition of magnetics to the impedance platform? How has this changed the stability and accuracy in your cases?

Historically, impedance was the only way that the legacy EnSite™ system was able to track the catheter location. With the new EnSite Precision™ System software, a magnet has been added to the impedance platform, and so the fidelity and accuracy of the points obtained and the location of the catheter (regardless of patient movement, deep breaths, or coughing) has been well maintained. The magnet has really improved the localization of the catheter in 3D space as well as the fidelity of the points in that space. The spatial resolution and stability have also been markedly improved with the addition of the magnet. 

How important is a flexible mapping system platform, and being able to use the right catheter for the right procedure to provide an efficient workflow? What are the benefits over the competition? 

EnSite systems have always had the benefit of having an open architecture, meaning I can take any catheter made by any company and utilize it for a procedure for precise 3D mapping. They have always maintained this open architecture platform, and it has allowed me to do all different types of procedures and be accustomed to using their mapping tool even with competitor’s catheters. Some competitors do not allow open architecture, and I’ve shied away from using certain competitor tools because of this. The addition of the magnet only allows me to use their magnetically enabled catheter with the current system; however, I still have open architecture for impedance mapping (without magnetic mapping). This flexibility allows me to choose the best catheter for the case.

What advice would you have for your peers who are considering using EnSite Precision?

If you are someone who relies on 3D electroanatomical mapping for your procedures and are doing complex ablation, it’s definitely a major step forward. The automation will improve the efficiency of your procedures, the rapidity in which you can collect points, and make you capable of taking care of more patients in a given day. If you are performing 2 or 3 ablations per day, you could potentially add an additional procedure because of the added time that you’ll have with this improved mapping tool. 

In regard to the Assurity MRI™ Pacemaker, what does an MRI-conditional pacemaker mean for patients?

Implanting pacemakers in patients with indications was a deal-breaker for those who might develop the need for an MRI down the road. The addition of MRI safety to the pacemaker platform is a considerable improvement — it allows us to implant these devices and not have to worry that a patient will be prohibited from a diagnostic MRI in the future. It gives us peace of mind when implanting these devices that patients will have access to these advanced imaging options later on. 

Tell me about your experience using the Tendril™ MRI lead with Assurity MRI Pacemaker.

The Tendril MRI leads must be used with the MRI-safe device, so again, I was originally skeptical because there was a small increase in French size of the lead tip. However, this has really not impeded me from using the lead in the way I was previously using the 2088 leads. I’ve been very pleased with the functionality of the lead and the ease of implantation.  

What does the Assurity MRI-conditional pacemaker bring that competitors do not?

In general, I think that St. Jude Medical devices are better shaped to fit into thinner and older patients, which is our typical pacemaker patient population in South Florida. There is also good use of RF antenna technology for real-time device interrogation during the implant, as well as their Merlin@home™ transmitter monitoring. Therefore, this device offers MRI-safe features, easy handling of leads, and the ability for the device to be remotely interrogated and followed. Many of the competitors do not have all of these attributes. 

Tell us about your first implant of the Assurity MRI pacemaker.

The first implant was in an elderly female with syncope and complete heart block. The procedure time was the typical 25 minutes for an implant. The patient did very well, there were no complications, and I was very pleased with how the leads handled as well as with the device itself. The patient went home post-op day 1. The patient was very pleased to learn that she had an MRI-safe device and that I successfully treated her complete heart block. 

How have your follow-up conversations gone with that first patient who was implanted?

All the follow-ups so far have been excellent. The patient is doing well. She has returned to playing tennis and her normal active lifestyle, despite her advanced age of 91 years old. 

What types of patients are you implanting with MRI devices?

Currently, any patient that has a pacemaker indication will get an MRI-safe pacemaker in my lab. 

Is there anything else you’d like to add?

Yes, I’d like to add that I think that one thing that differentiates St. Jude Medical from their competitors, in addition to their novel and cutting-edge technology, is that their support team and the clinical representatives and technicians that staff the cases are extremely knowledgeable and geared toward helping the doctor provide the best patient care possible.

Disclosure: The author has no conflicts of interest to report regarding the content herein.