Is ablation technology history repeating itself?
The history of technological advancements in ablative treatment for cardiac arrhythmias is anything but boring. In this blog, I will touch on key moments per decade that helped to shape the ablative treatment of cardiac arrhythmias. The history of cardiac ablation takes us through the transition from direct current (DC) to thermal ablation methods...and then back to the original DC applications.
In the past 60+ years, we have evolved from theories that involve micro explosion inside the heart to scorching and freezing temperatures, and NOW to the non-thermal (or low-thermal) approaches that will continue to revolutionize the field.
1960 - 1970
While the world was fascinated by witnessing man's first steps on the moon, early electrophysiology experts were busy utilizing diagnostic tools to guide and direct surgeons for surgical treatment of cardiac arrhythmias.
1970 - 1980
The study of electrical patterns on the endocardial surface continued while the mainstream public was strutting their stuff in polyester suits and platform shoes. The EP catheter technology improvements and information observed continued with the purpose of use as a guide for surgical treatment.
1980 - 1990
While we witnessed music videos introduced by MTV, technology continued to advance, bringing personal computers (larger than a microwave) into millions of homes and the possibility of a less invasive alternative to surgical treatment of arrhythmias.
Even though electrophysiology wasn't recognized as a mainstream discipline in cardiology, two leaders from UCSF and Duke were focused on research and advancement for endocardial treatment of cardiac arrhythmias and were working on a catheter that could treat cardiac arrhythmias. Dr. Melvin Scheinman and Dr. John Joseph Gallagher were busy experimenting with DC ablation techniques using a defibrillator to perform catheter ablation in animal studies.
By 1986, the first electroporation ablation system was commercially available, the National Heart Hospital’s low-energy pulse generator, and research on cardiac electroporation continued to evolve with the development of specialized ablation catheters that distributed current over larger electrodes. There remained some challenges to the widespread use of DC ablation clinically. At the time, the concern with direct current ablation was over the barotrauma that direct current ablation caused. It was believed that this was occurring due to micro explosions referred to as flash arcing.
1990 - 2000
The decade of peace and prosperity witnessed the explosion of access to the World Wide Web and while most were enjoying another episode of Friends, research was being done on the use of DC ablation and mainly, how to contain the misconception of micro-explosions. This barotrauma concern propelled the continued work and research on radiofrequency ablation methods as it surpassed DC ablation in research and use.
During this decade, radiofrequency (RF) catheter ablation became the predominant technology used in arrhythmia treatment while DC ablation almost disappeared. Even though RF ablation was the primary method utilized by 1990, we needed to address the need for deeper lesions and decreased risk of coagulum. In 1999, the first irrigated tip catheter was approved for commercial use to address these concerns.
2000 - 2010
We connected with lost friends and high school romances as we shifted from My Space to Facebook, and as the world listened to Lady Gaga on the new and improved MP3 player, the iPod, the electrophysiology world was studying the effects of radiofrequency ablation on cardiac tissue.
It was becoming evident that the lesions formed by RF displayed acute lesions with inflammation and hemorrhage around a central area of necrosis. These areas with inflammation at the border of central necrosis may have explained the higher recurrence rates of paroxysmal atrial fibrillation (after the healing process). Some of the technical modifications during this time (larger distal electrode and saline cooling), helped the creation of larger and deeper lesions.
In 2009, the first saline-cooled catheter was approved for the treatment of atrial fibrillation. To address the collateral damage potential with larger and deeper lesion delivery with radiofrequency ablation, the first cardiac cryoablation balloon catheter was approved in 2010, preceding the release of Disney’s Frozen by three years!
2010 - 2020
While we were singing “Let It Go” in our cars during the morning commute, the EP community witnessed continued growth and progression in thermal ablation technology. Necessary technology advancements addressed the pitfalls of RF associated with the use of thermal energy to treat cardiac arrhythmias.
By 2014, the first contact force measurement catheter was approved for commercial use. We saw improved recurrence rates in paroxysmal atrial fibrillation groups with contact force sensing catheters. However, the risk of collateral damage during RF ablation remained.
2020 - Current
Locked in our homes without extra toilet paper, we connected with our world through Zoom and Facetime while the COVID pandemic exploded. The EP community remained resilient while continuing to work on the evolution of thermal ablation tools. Researchers remained acutely aware of the non-discriminate effects of thermal ablation. As they researched thermal methods for the safer delivery of effective lesions, the early concepts of DC ablation were being studied and finetuned for the eventual re-introduction of an alternative to thermal ablation – Pulsed Field Ablation (PFA).
A BLAST FROM THE PAST...
In 2021, the first pulsed field ablation (PFA) catheter was approved for commercial use to treat cardiac arrhythmias. Unlike traditional RF ablation which uses heat energy, or cryoablation which uses freezing energy, PFA utilizes pulsed electric fields to create irreversible electroporation (or leaky and unstable cell membranes), disrupting the abnormal electrical signals responsible for arrhythmias. So many companies worldwide are in a race for the perfect solution. Will the catheter with thermal and non-thermal (or low-thermal) capabilities be the new ablation tool of choice?
It is exciting to imagine what this decade may produce in cardiac ablation to treat arrhythmias. In my 17-year career in EP, I have witnessed unprecedented growth from searing heat to cool innovations. And now, options ranging from thermal to non-thermal (or low-thermal) approaches have brought about potentially safer, more precise, and less time-consuming treatment options for patients with heart rhythm disorders. As technology continues to advance, we can eagerly anticipate more exciting breakthroughs that will continue to shape the future of cardiac ablation.
Check out the results from the much-anticipated presentation of the ADVENT trial presented at the European Society of Cardiology on August 27, 2023.