Electrophysiology in the “Real” World

Fifteen years of donning a lead apron has taught me many lessons. A very wise friend once told me success in any endeavor really involves mastering the obvious. This is clearly the case in practicing medicine and more specifically, achieving favorable results in the electrophysiology lab. Our lab is humbly equipped. There is a late model mono-plane fluoroscopy unit, a singular three-dimensional mapping system, an intracardiac ultrasound (ICE) device and an irrigated ablation system. A robot, MRI and multiple 3D mapping systems are notably absent. Enough equipment is available to achieve success, but not so much to allow dust to settle. So what could this non-academic Thoreau-like setting offer to the cohort of EP Lab Digest readers? An attempt, not certainly comprehensive, and not likely universally agreed upon, to outline some observations, theorems and lessons learned over the years. Presented herein are notions — some specific and others more general — that hopefully will help achieve success in the EP laboratory. Theorem number one: Strive for flexibility of the mind to learn new things. An electrophysiologist must be a lifelong learner. Consider for example, upon finishing training in the 1990s, there was no formal teaching on the transseptal puncture, and CRT devices were yet to be imagined. In fact, when first asked of the possibility that a left ventricular lead could benefit congestive heart failure, I was dismissive and unimaginative. But as all good doctors do, an electrophysiologist needs to accept the necessity of the learning process and know how to learn new techniques, technologies, and novel approaches so as to avoid becoming the aged doctor who clings to the past and refuses to learn the new. Theorem number two: Framing the problem and adjusting expectations of the patient. Seems simple, but so much of our success in electrophysiology is from having an educated patient who understands the problem at hand, the goals of the intervention and expectations post procedure. Examples abound, but take the patient who undergoes a primary prevention ICD implant expecting an “improvement” in their well-being. “Doctor, no one told me the ICD would not help my chest pain and breathlessness,” they say. Even more pertinent an example is the atrial fibrillation (AF) patient referred for left atrial ablation. With long-term success rates for AF ablation in the 65% range, many patients requiring multiple procedures, and a CHADS score determining the ability to discontinue anticoagulation post procedure, it seems best to introduce the patient to you, the electrophysiologist, as a friend — this treatment will encompass a journey rather than a single curative procedure. To the patient with AF, I often say, “you and I are going to have to become friends for a while — AF treatment is unlike the finality of removing an appendix.” So, when the patient has recurrent AF or maybe just benign palpitations after the first “successful PVI,” life is easier for doctor and patient alike. Checklist of Specific Observations and Recommendations On Pacing/ICDs: 1. Excluding congenital heart block, give pause before implanting pacemakers in the young patient. Reflecting on a long pacing experience, it is but a rare young patient who requires pacing. Many youthful patients have inappropriately implanted hardware placed for visually impressive but vagally mediated bradycardia. Pacemakers are not insurance policies and unlike the insurance policy holder, the pacemaker patient incurs significant long-term risk. 2. During the device implantation process, avoiding acute and sub-acute perforation is as simple as using a passive fixation lead in the right ventricle. From a smart friend and fellow electrophysiologist, stop using active fixation leads in the RV and there will be no more perforations! Ten years ago, this advice was heeded and proven correct. To the extractors who complain, I echo advice I heard one father give to a child, in which he urged the child not to worry about something far in the future that has yet to happen. To those who worry about dislodgment, I tell them to read the studies that refute the concern that passive leads dislodge more frequently. 3. Avoid the use of heparin or low molecular weight heparin after device implantation. Literature on the safety of implantation of high-risk thromboembolic patients with therapeutic INRs is clear and personally validated. Device surgery with an INR between 1.6-2.5 precludes the need for post-operative heparin and thus lowers the risk of post-operative hematoma.1 4. When implanting an active fixation lead, always check for injury current on the electrogram. An injury pattern implies solid fixation and dislodgment is avoided. 5. Understand the statistical limitations of the ICD, including both the importance of co-morbidities in predicting statistical benefit and the prognostic implications of ICD shocks.2,3 Consider the spectrum of benefit from an ICD: a young mother with syncope and long QT syndrome on one pole and an elderly dialysis patient with class IV heart failure and cancer on the other. Is the patient considered for an ICD like the cohort of patients in which ICDs were shown beneficial, or will non-arrhythmic issues limit the ICD’s overall mortality benefit? For example, will the medically non-compliant smoker with inoperable coronary disease and lung disease really enjoy a significant reduction in overall mortality from a primary prevention ICD? 6. ICDs affect one’s mode of death; specifically, they decrease the likelihood of a painless sudden death. Although sometimes challenging, occasionally emotionally draining and poorly reimbursed, it is appropriate and right to discuss a patient’s end of life wishes and goals of care before ICD implantation. 7. Dialysis patients warrant extreme caution when devices are considered. Permanent device implantation essentially eliminates the ipsilateral upper extremity as a future hemodialysis access possibility. On Ablation: 1. In paroxysmal supraventricular tachycardia, take time to assure the diagnosis. Especially in AV nodal reentrant tachycardia (AVNRT), make sure that atrial activation proceeds from low to high and that A’s and V’s are associated. Not infrequently, atrial tachycardias (especially para-hisian ATs) mimic AVNRT. 2. Avoid being penny wise and pound foolish: Make life easier for yourself and use enough catheters to enhance both the speed and accuracy of the diagnosis. A few inexpensive quadripolar catheters will not substantially increase the cost of healthcare. A multipolar coronary sinus catheter is very often helpful, as it provides a clear picture of left atrial activation. 3. In cavotricuspid isthmus ablation, use a long sheath with an 8 mm tipped ablation catheter. The specifically curved “flutter” sheaths designed to facilitate contact on the isthmus have proven exceedingly useful, as has the 8 mm tipped ablation catheter. 4. Generally speaking, when an ablation strategy continues to fail, do something different. Rewind or go back and consider the sureness of the diagnosis and approach the problem in a new direction. On Atrial Fibrillation Ablation: Our AF ablation experience, like most in the non-academic setting, encompasses patients with paroxysmal and recently persistent AF. It was not long in our experience before it was obvious that permanent AF patients were poor candidates for ablation in our lab. During the transseptal puncture, if something does not feel right, it probably isn't and it is best to not push forward. Stop, rewind and approach again, being sure that the needle is in the fossa. Although expensive, ICE is exceedingly helpful in guiding access to the left atrium. ICE is also helpful in the learning process. It provides both visual confirmation and correlations to the tactile sensations of an appropriate needle/ sheath position. During pulmonary vein (PV) isolation, when not excessively distal the PV carina region is an important ablation target.4 A colleague often remarks when the PV potentials disappear while ablating in the carina region, “it is always in between the veins.” CT scans of the chest provide anatomical information that some feel are helpful for left atrial ablation. In our early experience, we did obtain CT scans pre-ablation, but found merging the images time consuming and often not helpful. Third party payers’ denial of reimbursement forced us to stop using the pre-ablation CT. The use of ICE-guided 3D reconstruction and the soon to be installed advanced 3D reconstruction technology have substituted adequately for the CT. Additionally, the dangers of radiation exposure have come to light recently, and given the minimal incremental benefit, there seems little reason to perform routine pre-ablation CT scanning. General anesthesia (GA) has proven remarkably helpful to the doctor and patient. Opponents to its use correctly point out that conscious patients can provide feedback when RF energy is close to the esophagus. Like most labs, our AF ablation experience began with the use of conscious sedation, but lately we have changed to general anesthesia and offer the following observations: 1. GA aids the non-youthful AF patient to lie supine for the numerous hours of the procedure and post-procedure recovery. 2. Immobility induced with GA has facilitated 3D mapping, as even small patient movements can disrupt the reconstruction. 3. Respiration is often accentuated greatly with conscious sedation, and this renders catheter stability challenging. Given the high recurrence rate of PV reconnection, catheter stability in the left atrium should not be understated. The smooth rhythmic respirations of a patient under GA makes catheter stability much easier to achieve, and in doing so, may improve both the quality and accuracy of the left atrial lesions. 4. Fluoroscopy times and procedure times have proven much less with GA. 5. Patients often need a second procedure, so satisfaction with the first makes accepting a second, often successful procedure more likely. It is our observation that GA results in better patient satisfaction. 6. Localizing the esophagus in real time with ICE and a fluoroscopically visualized temperature probe helps guide posterior left atrial wall ablation so as to avoid collateral damage. Conclusion The above ideas are some observations and humble suggestions culled from my many hours and years in the laboratory. The suggestions will surely change in the future as the practice of electrophysiology is dynamic and without doubt, there are indeed many avenues leading to success in the EP lab. As in all areas of the practice of medicine, patience, attention to detail, homework and mostly the desire and ability to learn are paramount. The gratification from success in the lab is infectious, and to those who toil adjacent to the fluoroscopy unit with a lead apron and strive to repair the ailing cardiac electrical system, I say congratulations and am proud to call myself a colleague. For more information, please visit: https://drjohnm.blogspot.com/