A left ventricular epicardial to right ventricular endocardial dominant frequency gradient exists in human ventricular fibrillation

Abstract

We hypothesized that in patients with left ventricular dysfunction undergoing implant of a biventricular ICD, the local dominant frequency during early induced ventricular fibrillation would be higher at an epicardial left ventricular position compared to an endocardial right ventricular position. Patients undergoing implant of a biventricular ICD were studied. During ventricular fibrillation induction, bipolar electrograms were recorded from leads at an epicardial left ventricular position and an endocardial right ventricular position. Overlapping 2-s fast Fourier transforms were obtained for 6s of ventricular fibrillation. The dominant frequency and organizational index were compared. Thirty-four patients (20 men, age 64 ± 11years) underwent 57 inductions of ventricular fibrillation. Eighteen patients had non-ischemic dilated cardiomyopathy and 16 had ischemic dilated cardiomyopathy. The dominant frequency was higher at a lateral epicardial left ventricular position than an apical endocardial right ventricular position in 18 patients with non-ischemic dilated cardiomyopathy (LV epicardial 5.34 ± 0.37Hz, RV endocardial 5.09 ± 0.41Hz, p < 0.001), but not in 16 patients with ischemic dilated cardiomyopathy (LV epicardial 4.99 ± 0.57Hz, RV epicardial 4.87 ± 0.65Hz, p = 0.094). In patients with non-ischemic dilated cardiomyopathy, there is a dominant frequency gradient during early ventricular fibrillation induced at ICD testing from the lateral left ventricular epicardium to the apical right ventricular endocardium.