Virtual heart helps identify patients at risk of dangerous heart rhythms

17th May 2016

Doctors in America say they have developed a 3-D virtual heart assessment tool to help them predict which patients are at risk of a dangerous heart rhythm.

The virtual hearts allowed researchers to see the geometry of the patients’ hearts, how electrical impulses moved through them, and what impact scar tissue had on the risk of having a dangerous rhythm.

They say the test, when used on people who had had a heart attack, gave more accurate predictions of which patients were at risk than other current techniques.

Those thought to be at risk can be given an internal defibrillator (ICD), which will shock the heart back into a normal rhythm. 

“Our virtual heart test significantly outperformed several existing clinical metrics in predicting future arrhythmic events,” said Dr Natalia Trayanova, a professor of biomedical engineering at Johns Hopkins University School of Medicine. “This non-invasive and personalised virtual heart-risk assessment could help prevent sudden cardiac deaths and allow patients who are not at risk to avoid unnecessary defibrillator implantations.”

Dr Tyanova joined forces with cardiologist and co-author Katherine C. Wu, an associate professor at Hopkins, for the study. They led a team in using magnetic resonance imaging (MRI) records of heart attack patients with damaged heart tissue, a risk factor for dangerous heart rhythms. They used data from 41 patients who had a reduced ejection fraction — a measure of how much blood is being pumped out of the heart – of less than 35 per cent.

Usually, doctors recommend ICDs for such patients and all of those in the study received one. The team looked at pre-implant MRI scans of the patients and personalised, digital replicas of their organs. They then simulated the cardiac cells’ electrical processes and communications, bringing the computer models to “life.”

Some of the replicas developed dangerous heart rhythms, and others did not.

The team found that those who tested positive for arrhythmia risk in the model were four times more likely to have developed arrhythmias than those who tested negative.

“By accurately predicting which patients are at risk of sudden cardiac death, this approach will provide doctors with a tool to identify those patients who truly need the costly implantable device, and those for whom the device would not provide any life-saving benefits,” Dr Trayanova said.

Source: Arevalo H, Vadakkumpadan F, Guallar E, Jebb A, Malamas P, Wu K, et al. Arrhythmia Risk Stratification of Patients After Myocardial Infarction Using Personalized Heart Models. Nature Communications. 2016.