MUSC Health has become the first hospital in South Carolina and the second in the U.S. to use a new, high-tech catheter called the HD Grid (Abbott; Chicago, IL) to give physicians more insight into the mechanisms of heart rhythm problems, such as ventricular tachycardia (VT).

In a person with VT, abnormal electrical signals cause the heart to beat more quickly than normal. It can run the gamut from mild, with no symptoms, to dangerous, causing the heart to stop.

“Previously understood mechanisms of arrhythmias may have oversimplified circuits of these fast heart beats,” explains Jeffrey R. Winterfield, M.D., director of the Ventricular Arrhythmia Service at MUSC Health. “Using this technology, we have gained a much richer and more detailed sense of how to localize circuits, which may result in shorter and safer procedures.”

So far, the MUSC Health team has used the technology on five patients. “The outcomes exceeded our expectations,” says Winterfield. “We shaved off two hours from procedure times for complex VT cases.”

The new catheter is similar to other high-density catheters but has an important difference. “It has multiple spines, each with four small electrodes evenly spaced from each other,” explains Winterfield. “These small and tightly spaced electrodes create a very small and sensitive antenna to detect abnormal electrical activity in scarred or diseased areas of the heart.”

Older catheters would be limited to just two electrodes that are larger and more widely spaced. “The result of the old arrangement would be that we would see only the larger signals and miss the rich and detailed circuits in the very diseased areas of the heart,” says Winterfield.

Winterfield is collaborating with Roderick Tung, M.D., at the University of Chicago to open a clinical trial assessing whether using ultra-high-density mapping methods with the HD Grid catheter can reduce procedure times and improve outcomes for VT ablation. VT ablation involves using radiofrequency to destroy small areas of scarred heart tissue responsible for causing VT.

Progressnotes Summer 2018