Abstract 19326: Ventricular Arrhythmia is Correlated to Novel Indices of Myocardial Viability in the Peri-Infarct Region Using Manganese Enhanced MRI
Introduction: While a significant correlation between the peri-infarct region (PIR) and ventricular arrhythmia has been well recognized, reliable non-invasive detection of this arrhythmogenic region, consisting of injured but viable myocardium, is difficult.
Hypothesis: We hypothesized that the viable myocardium in the PIR demonstrated by novel manganese-enhanced MRI (MEMRI) correlates with inducibility of ventricular arrhythmia.
Methods: In 12 pigs with anterior MI due to LAD ischemia-reperfusion injury (IR), we performed MEMRI, delayed-enhanced MRI (DEMRI) and programmed electrical stimulation (PES) from the RV apex using burst pacing and extra-stimuli. We related baseline MEMRI indices to arrhythmia inducibility (baseline S1 - coupling interval at VT) at day 60 post-IR.
Results: In 12 pigs (41.8±7.6 kg, LVEF 27.7±8.8 %,) infarcts were reliably established using LAD ligation. Measurement of % infarct volume by DEMRI vs. MEMRI was 22.7±10.3 % vs. 8.2±3.9 %*, *p<0.05, demonstrating significant viability in the PIR by MEMRI and mean PIR detection of 9.2±5.9 cc. This discrepancy represents a possible over-estimation of the infarct scar by DEMRI. The lower threshold for burst pacing and extra-stimuli to induce VT/VF correlated strongly with increased PIR viability as shown by MEMRI (R2=0.469, p=0.05) as shown in the Figure.
Conclusions: Using novel MEMRI indices, we demonstrated a significant correlation between MEMRI measurement of PIR viability and ventricular arrhythmia inducibility by PES in a porcine IR model. These data are the first to associate the viable morphology and LV scar anatomy at high spatial resolution in the PIR with potential implications for clinical arrhythmia risk stratification in ischemic cardiomyopathy.
Author Disclosures: A. Tachibana: None. J. Zaman: None. E. Neofytou: None. H. Sano: None. J. Lyons: None. I. Fumiaki: None. Y. Mitsutake: None. J. Gold: None. S. Narayan: None. R. Dash: None. J. Wu: None. P. Yang: None.
- © 2016 by American Heart Association, Inc.