Abstract 18014: Image-Based Patient-Specific Simulations of Ventricular Electrophysiology for Sudden Arrhythmic Death Risk Stratification
Low left-ventricular ejection fraction (LVEF), the main criterion used in current clinical practice to stratify sudden arrhythmic death (SAD) risk, and select patients for prophylactic implantable cardioverter defibrillator (ICD) treatment, has very low sensitivity and specificity. Arrhythmia inducibility in clinical electrophysiological study (EPS) can improve SAD risk prediction, but it is invasive and expensive. We seek to demonstrate that image-based patient-specific simulations of ventricular electrophysiology can be used as a non-invasive and economical surrogate for clinical EPS in predicting SAD risk. Data from 20 patients with myocardial infarction and low LVEF, who were scanned with late gadolinium enhanced cardiac MRI prior to ICD implantation, and followed for appropriate ICD firing and SAD, were used. Nine patients had events and eleven did not. For each patient, a multiscale, biophysically-accurate ventricular model, including inexcitable scar, electrically remodeled gray zone, and estimated fiber orientations, was built from the image data. A programmed electrical stimulation (PES) protocol with 2 ventricular extrastimuli, similar to that used clinically, was performed in each model from 17 LV endocardial sites corresponding to the 17 AHA regions. An inducibility index was calculated for each patient as the proportion of the PES sites from which sustained ventricular arrhythmia was induced. The mean inducibility index was 0.21±0.14 for patients who had an event vs. 0.09±0.14 for those who did not (p<0.05). The figure shows geometries and simulated activation maps of a patient without event (top row) and with event (bottom row). All patients with events had inducibility stimulated from at least 1 site (range: 1-8). In conclusion, we have developed a new index computed from noninvasive simulations of ventricular electrophysiology, that may be able to stratify SAD risk and guide prophylactic treatment delivery.
- Magnetic resonance imaging
- Sudden cardiac death
- Implantable cardioconvert defibrillator
- © 2013 by American Heart Association, Inc.