Summarize and humanize this content to 2000 words in 6 paragraphs in English
Virtual replicas of individual patients’ hearts have allowed doctors to refine and personalize a lifesaving medical procedure for dangerous rhythm disturbances.
Like flight simulators for physicians, these “digital twins” give doctors a way to preview different intervention options on computer models of a patient’s anatomy before ever entering the treatment room. And early results suggest the approach could lead to better outcomes than standard practices today, researchers report April 1 in the New England Journal of Medicine.
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Heart models may be just the leading edge. Similar virtual replicas could soon help guide planning and treatment decisions across many areas of medicine, from microbiome therapies to orthopedic surgery.
“We’ve come to the age where we can start using digital twins to mimic actual physiology within the body,” says Jonathan Chrispin, a cardiac electrophysiologist at Johns Hopkins University School of Medicine. “That ability could help move forward research as well as improve clinical outcomes.”
Doctors typically treat dangerously fast heartbeats by threading energy-delivering catheters through blood vessels in the groin and into the heart. Once there, they search for the source of the faulty electrical activity and ablate, or destroy, the responsible tissue. This leaves behind tiny scars that stop the errant signal from spreading.
This minimally invasive procedure restores a steady heartbeat in about two-thirds of patients.
Chrispin saw an opportunity to improve those odds. Working with Johns Hopkins biomedical engineer Natalia Trayanova and colleagues, he helped build digital doppelgängers of the heart that could pinpoint likely targets in advance.
The process begins with high-resolution MRI scans that capture the heart’s structure and highlight patches of damaged tissue left by prior injury. Software converts these images into a three-dimensional digital reconstruction of the heart muscle, assigning different electrical properties to healthy and deteriorated regions.
Computer simulations then model how electrical signals travel through the heart — where they may slow, split or loop back on themselves in ways that can trigger dangerous rhythms. Researchers can then test virtual ablations on the model to identify the most effective way to shut down those faulty signals before performing the real procedure.
To re-create abnormal heartbeat patterns in this cardiac digital twin, electrical stimulation is applied at a virtual “pacing site.” This generates waves of electrical activity that reveal how ventricular tachycardia (VT) can emerge in a damaged area, depicted in yellow.Johns Hopkins University
“It’s a very powerful tool for pre-procedural planning,” Trayanova says. In effect, she says, “you treat the digital twin before you treat the patient.”
The team executed the strategy in 10 people with ventricular tachycardia, a potentially fatal rhythm disorder that originates in the heart’s lower chambers. Though relatively uncommon, the condition contributes to tens of thousands of sudden cardiac deaths in the United States each year.
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With the virtual heart model to guide them, Chrispin and his colleagues showed that they could quickly direct their catheters at problem areas, shaving the roughly three-hour procedure down to about 30 minutes and reducing risks associated with prolonged sedation.
At the end of the procedure, the abnormal rhythm could no longer be triggered — a standard way to evaluate whether the faulty electrical circuits have been successfully shut down.
Two trial participants did experience brief recurrences of abnormal rhythms within a few weeks of their procedures. But in both cases, implanted defibrillators delivered corrective electrical pulses that restored a normal heartbeat. And after months to years of additional follow-up, all 10 participants remained free of sustained dangerous rhythms, with most no longer needing antiarrhythmic drug therapy.
The approach “is very innovative,” says Babak Nazer, a cardiac electrophysiologist at the University of Washington in Seattle who was not involved in the study. “These are state-of-the-art cardiac simulations.”
Further evaluation in large multicenter trials will be needed to determine whether the technology consistently leads to meaningful improvements in patient care, Nazer says. “That’ll tell me if it’s a game-changer or a physiologically elegant widget.”
