[Area reduction effects on atrial fibrillation inducibility].
Atrial fibrillation inducibility and sustenance depend upon the atrial electrophysiologies such as wavelength and upon the anatomical factors such as atrial area. To determine the mechanism of prevention of atrial fibrillation by atrial mass reduction, 20 adult mongrel dogs underwent the right atrial isolation procedure and atrial fibrillation duration, functional refractory period, conduction velocity, wavelength, atrial area and weight were examined pre- and postoperatively. The animals were divided into two groups: right atrial isolation group (RAI-group, n = 10) and control group (C-group, n = 10) in which cardiopulmonary bypass was undergone for the identical duration and the right atrial isolation was not performed. Atrial fibrillation duration significantly prolonged from 9.2 +/- 2.5 sec preoperatively to 43.6 +/- 0.4 sec postoperatively in the control group. However, in the RAI group, the duration significantly shortened from 11.4 +/- 2.7 preoperatively to 1.2 +/- 10 sec postoperatively. The wavelength at the non-isolated atrium did not show significant difference between the control group and the RAI group. The atrial area decreased from 61.9 +/- 4.1 cm2 to 46.3 +/- 3.5 cm2 postoperatively in the RAI group, while the area did not change in the control group. We conclude that the reduction in the effective atrial area affects the inducibility of atrial fibrillation.
Hosaka
H
H
Second Department of Surgery, Nippon Medical School, Tokyo, Japan.
D000818:Animals; D001281:Atrial Fibrillation / Q000517:prevention & control*; D004285:Dogs; D004562:Electrocardiography; D006325:Heart Atria / Q000033:anatomy & histology* / Q000601:surgery; D009929:Organ Size; D013997:Time Factors