Both Purkinje Cells and Left Ventricular Posteroseptal Reentry Contribute to the Maintenance of Ventricular Fibrillation in Open-Chest Dogs and Swine Effects of Catheter Ablation and the Ventricular Cut-and-Sew Operation

• Published in: Circulation Journal Vol. 72; no. 7; pp. 1185 - 1192
• Main Authors: Pak, Hui-Nam, Kim, Gwang Il, Lim, Hong Euy, Fang, Yong Hu, Choi, Jong Il, Kim, Jin Seok, Hwang, Chun, Kim, Young-Hoon
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Circulation Society 2008
• Subjects: Animals; Catheter Ablation; Cut-and-sew operation; Disease Models, Animal; Dogs; Electrocardiography; Endocardium - cytology; Heart Septum - cytology; Heart Septum - physiology; Heart Septum - surgery; Heart Ventricles - cytology; Heart Ventricles - surgery; Myocardium - cytology; Papillary muscle; Papillary Muscles - cytology; Papillary Muscles - physiology; Papillary Muscles - surgery; Purkinje; Purkinje Fibers - cytology; Purkinje Fibers - physiology; Purkinje Fibers - surgery; Species Specificity; Swine; Ventricular fibrillation; Ventricular Fibrillation - physiopathology; Ventricular Fibrillation - surgery; Ventricular Function
• ISSN: 1346-9843; 1347-4820
• DOI: 10.1253/circj.72.1185

Background Radiofrequency catheter ablation (RFCA) targeting the left ventricular posteroseptum (LVPS) and posterior papillary muscle (PPM) terminates or prevents ventricular fibrillation (VF) in rabbit and dog hearts. However, whether the mechanism of VF maintenance is reentry or focal Purkinje firing is unclear. Methods and Results In the present study the effects of RFCA (endocardial ablation of PPM+LVPS in 7 dogs and 7 swine), left ventricular anterolateral wall ablation (LVAL in 7 dogs), and the cut-and-sew operation (CSO: along the left ventricular posterior wall (LVPW) beside PPM in 7 swine) on VF inducibility were compared. (1) VF inducibility was decreased from 100±0% to 21.9±31.2% (p<0.0001) by PPM+LVPS endocardial ablation, but not by LVAL ablation in dogs. (2) LVPW CSO reduced VF inducibility (100±0% to 43.6±9.5%, p<0.0001) in swine. (3) In contrast to the canine Purkinje network, which is mostly localized to the subendocardium, the swine Purkinje network extends to the subepicardial layer with a higher density (p<0.001). Conclusion Both PPM+LVPS ablation (Purkinje destruction) in dogs and LVPW CSO (blocking reentry) in swine reduce VF inducibility, suggesting that in both species focal firing from the Purkinje network and reentry around the PPM contributes to the maintenance of VF. (Circ J 2008; 72: 1185 - 1192)