Scientists Develop 3-D Virtual Heart Assessment Tool to Help Diagnose Life-Threatening Arrhythmia

Patients with life-threatening arrhythmia needs to implanted with a small defibrillator that can sense abnormal rhythm in the heart and jolt it back to normal phase, but the prophylactic insertion of implantable cardioverter defibrillators (ICDs) is very invasive, costly and comes with a risk of its own.

With this in mind, researchers from Johns Hopkins University developed a non-invasive 3-D virtual heart assessment tool to help doctors determine whether a particular patient faces the highest risk of a life-threatening arrhythmia and would benefit most from a defibrillator implant.

At present, physicians use blood pumping measurement that gauge ejection fraction of the patients. Ejection fraction is a measure of how much blood is being pumped out of the heart. Patients with rejection fraction below 35 percent were advised to have ICD, according to their press release.

But researchers believe that this kind of approach in identifying patients with most risk of sudden death due arrhythmia has low sensitivity and specificity. With that in mind, they developed a new approach using distinctive magnetic resonance imaging (MRI) records of patients who had survived a heart attack but were left with damaged cardiac tissue that predisposes the heart to deadly arrhythmias to properly predict patients that are of high risk of sudden death.

To test out their new virtual-heart arrhythmia risk predictor or VARP, researchers made a personalized replica of the heart of 41 patients who received ICDs, due to low ejection fraction, using pre-implant MRI scans. Using advance computer modeling techniques, the researchers predict the chances of the patient to experience life-threatening arrhythmia by taking into account the electrical processes in the heart and communication among cells.

They then test the efficacy of their predictions by comparing the results defibrillator recipients' post-implantation records. The researchers discovered that patients who tested positive for arrhythmia risk by VARP were four times more likely to develop arrhythmia than those who tested negative. Also, VARP was able to predict the occurrence of arrhythmia four to five times better than the ejection fraction.

Their findings, published in the journal Nature Communications, show that VARP can be the new face of arrhythmia prediction that has the potential to prevent the unnecessary risk and cost of ICDs.