264 Is ventricular fibrillation different in ischemic compared to non-ischemic dilated cardiomyopathic human hearts?

Abstract

It is unknown if VF dynamics are dependent on the etiology of the cardiomyopthay. In this study we compared transmural dominant frequency gradient, during ventricular fibrillation (VF), in ischemic and non-ischemic dilated cardiomyopathic human hearts. The study was conducted in human langendorff model. These were ischemic (ICM, n = 5) and dilated (DCM, n = 5) cardiomyopathic human hearts explanted from patients undergoing cardiac transplant. Data was collected using an epicardial sock and an endocardial balloon each having 112 unipolar electrodes, arranged in 14 columns and 8 rows. Ischemia was induced by halting the perfusion to the heart and VF was initiated by brief application of 9V batter to epicardium. VF was recorded at onset, 90 seconds and 180 seconds for 20 seconds each. Dominant frequency (DF) was computed using Welch periodogram method as described in our previous studies. Repeated measure ANOVA was employed using mixed model in SAS. The mean DF in LV-endocardium and LV-epicardium is reported in table 1. At the onset of VF, no difference was observed between LV epicardium and endocardium in dilated cardiomyopathic hearts (P = 0.6) while the difference was statistically significant in ischemic cardiomyopathic hearts (P < 0.05). After 180 seconds of VF, there was a significant transmural DF gradient in both ischemic and dilated cardiomyopathic hearts (P < 0.05).Tabled 1 There is a LV transmural DF gradient during VF in both DCM and ICM after 3 minutes of ischemia. This gradient is established early in ischemia in ICM but not in DCM. These finding may relate to differential transmural ion channel remodelling that is dependent of the etiology of cardiomyopathic process.