title: Different types of long-duration ventricular fibrillation: can they be identified by electrocardiography.
abstract: We tested the hypothesis that after 2 minutes of ventricular fibrillation (VF), periods of highly organized activations occur on the endocardium, arising from an intramural mother rotor or triggered activity originating in the Purkinje fibers. In 6 anesthetized dogs, we recorded electrically induced VF from two-thirds of the endocardium with a 64-electrode basket catheter. In another 12 dogs, the study was repeated with the addition of the early afterdepolarization blocker pinacidil in 6 animals and the delayed afterdepolarization blocker flunarizine in the other 6 animals. We found that, in addition to periods of disorganized chaotic activation (type I pattern), at between 3 and 7 minutes of VF, 2 highly organized patterns were observed (type II pattern, regular activity and type III pattern, triggered activity). When present, these patterns were observed in all 64 electrodes simultaneously. Type II arises from the apex and may be an intramural mother rotor and type III arises focally in Purkinje fibers and may be caused by early afterdepolarizations. The optimal defibrillation strategy may be different for the 3 different VF patterns. Therefore, it is important to determine if these 3 patterns can be differentiated from the body surface electrocardiogram.
authors.affiliation: CARMA Center, Division of Cardiology, University of Utah School of Medicine, Salt Lake City, UT 35294-0019, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Xiangsheng
authors.initials: X
authors.lastname: Zheng
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Dosdall
authors.forename: Jian
authors.initials: J
authors.lastname: Huang
authors.forename: Raymond E
authors.initials: RE
authors.lastname: Ideker
mesh_terms: D000818:Animals; D003937:Diagnosis, Differential; D004285:Dogs; D004562:Electrocardiography / Q000379:methods*; D006329:Heart Conduction System / Q000503:physiopathology*; D008955:Models, Cardiovascular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014693:Ventricular Fibrillation / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology*