Working Through the Layers of Wide Complex Tachycardia
Date: September 17, 2010
Among the stories that he can cite from within his highly specialized area of electrophysiology, Hari Tandri likes to describe the patient who kept coming back.
The Gettysburg woman, 28, had been diagnosed with a genetic form of cardiomyopathy known for its propensity to produce a dangerously fast heart rhythm. She’d been given an implantable defibrillator to stop the episodes, but the condition was still getting the better of her. In the previous year, the device had to deliver a life-saving shock more than a dozen times.
Each time, the woman’s heart rate approached a deadly 200. “It was her youth,” says Tandri, “that saved her.”
But youth has its limits, and one episode compelled the woman’s local emergency-room crew to send her to Johns Hopkins. Enter Tandri, who specializes in handling exactly these sorts of complications.
The patient’s broader heart problem stemmed from arrhythmogenic right ventricular dysplasia, which carries a high risk of wide complex tachycardia. Episodes of this life-threatening rapid heart rate can add to small infarctions in the heart tissue that further impair its ability to attain a healthy rhythm.
Using an advanced form of MRI to create a three-dimensional electroanatomic map of the heart’s outer layer, Tandri was able to spot scar tissue that disrupted the patient’s cardiac circuitry. In his first procedure with the Gettysburg patient, Tandri cauterized her heart’s visibly disrupted circuits.
The patient’s heart rate eased, allowing Tandri and his team to discharge her from the hospital. But the woman came back with new episodes. Twice.
Although her initial procedure was successful, says Tandri, ridding her of one wide complex tachycardia unmasked another, and then another. “It was like peeling back layers,” he says.
In the end, the patient turned into one of Tandri’s better saves. Now 30, she has married, gotten a job as a medical secretary and is hoping to become a mom. Though Tandri says her case is unusual for the repeated ablation procedures, he adds that’s one of the condition’s challenges. The disruptions can be “like a patchy, meandering scar,” he says. The procedures must unfold in “a stepwise approach. We can only go after what shows up.”
With each ablation, he adds, “you only close certain doors, which then provide the paths for other doors to open, and you have to go back in and do the cleanup procedure again. But the good news is that, once we go in and do that, the patients do great.”