Cardiovascular surgical techniques and technology are advancing at rates that challenge both physicians and the facilities they work in to keep pace. Although the cardiac catheterization and electrophysiology (EP) laboratories in the Medical University of South Carolina's (MUSC's) Ashley River Tower (ART) were opened only 10 years ago, they recently underwent an extensive overhaul to ensure that the facility can continue providing cutting-edge cardiac care.
MUSC is a national leader in the management of complex ventricular arrhythmias and its Complex Ablation Program has experienced double digit growth over the last two years. This expansion reflects not only the rapid evolution of the overall field, but also a strong, continuous institutional commitment of support. Several years ago, hospital leadership recognized that reinvestment in the EP laboratories would soon be necessary to accommodate the new workflows and technical requirements of emerging ventricular tachycardia (VT) ablation technologies. To answer this challenge, Thomas Di Salvo, MD, Professor of Medicine and Chief of the Heart and Vascular Integrated Center of Clinical Excellence collaborated with Michael Denham, Chief Perioperative Officer, and Jeffery Winterfield, MD, Associate Professor of Medicine, Hank & Laurel Greer Endowed Chair in Electrophysiology, and Director of the MUSC Electrophysiology Program, to develop, design, and build a completely new EP laboratory at ART.
As part of a partnership with Siemens Inc., the lab includes new fluoroscopy and a next-generation mapping system from Biosense Webster, Inc., called CARTOv7. Super high density displays (VantageView) replaced small screens that were previously located at the foot of the bed. The larger, clearer displays provide a more vivid, 3-D image that is directly in the physician's line of site to facilitate navigation through the complex structures of the heart. As great an improvement as that may be, it's the CARTO v7 software that really makes the system revolutionary. "Since we started doing clinical cardio-electrophysiology studies, one of the Holy Grails has been to understand waveform conduction through the heart tissue. This new system mathematically calculates those conduction speeds and give us a sense of the direction in which it's moving – like a wind vector map that you might see on a weather forecast during hurricane season. On those, the arrows show the direction and velocity of the wind in different places. The map that this system generates shows us the areas with slowing of speeds or decelerations which is usually where we want to target with ablation," explains Winterfield.
The new system also allows the procedure to be completed much more quickly, reducing the risk for complications and potentially lowering costs. "With the old system, the areas of concern weren't so easy to see. There was a lot of guessing and we had to interpolate the point-by-point data ourselves. It was slow. We had to computationally make sense of it ourselves and it didn't always produce a clear picture of where the problem was. Now, we get the data very rapidly. This software program makes sense of it much more quickly and completely than we could." This is particularly important because, when an ablation procedure fails to stop the arrhythmia, a second procedure is often necessary. These repeated procedures are usually conducted in stages to reduce the risk for complications. "If we're more efficient, we can avoid having to stage procedures which could also reduce costs," adds Winterfield.
MUSC Health was one of seven centers world-wide that are participating on the advisory board for this new system and was the second in the world to use it, after Beth Israel Deaconess Medical Center in Boston. "We worked in collaboration with multiple physicians from major US and European centers as well as Israeli engineers from Biosense Webster to develop the algorithms and prove their effectiveness," says Winterfield. "And we picked a doozie for our inaugural case. The patient came in for a PVC ablation several months ago but aborted because of his risk for heart block. When the new lab was ready, we gave it another try and found the PVC right where the CARTO system predicted it would be. We could successfully and safely ablate it with no heart block. The map placed activation at a sinus rhythm point that correlated with the site of the PVC. This is a big development because there can be considerable shift between sinus rhythm and the PVC – even though the catheter remains in the same anatomical site. In our case there was a 7.3-millimeter shift between the two! But the system still calculated it correctly," Winterfield explains.
The engineers who designed the CARTO system were also impressed with the quality of the mapping signals in the newly renovated lab. The system relies on processing high-density signals to create the patient's electrical heart map and these signals must be extremely clear – meaning that that ambient electrical (background) noise must be minimal. "When the engineers came, they said it was the quietest and best lab they've seen anywhere in world. Typically, there's 100-900 microvolts of noise in the signal and we had under 10! I'm very proud that the lab is so well constructed. Just building it was a really difficult technical accomplishment!" exclaims Winterfield. "This is a huge step forward for us and for our patients with complex arrhythmias."
Opened in February 2019, this world-class EP lab is just one of the exciting ART renovations that have been recently completed or are underway. Similar renovations aimed at upgrading the other cardiac catheterization and EP labs will be taking place over the next 12 to 18 months. This strategy of proactive, long-term planning based on emerging technology is what has earned MUSC Health its reputation as a leader in providing advanced, innovative healthcare.