Influence of left atrial enlargement and body weight on the development ofatrial fibrillation: Retrospective study on 205 dogs

We studied 205 dogs with cardiac diseases associated with left atrial enlar gement (LAE). On the basis of electrocardiogram results, they were divided into: Group A, 50 dogs with atrial fibrillation (AF) and Group B, 155 dogs without AF. Group B was further subdivided in Group BI (123 dogs with sinus rhythm) and Group BII (32 dogs with cardiac arrhythmias other than AF). Bo dyweight (BMT) and left atrial diameter (LA) of Group A dogs were significa ntly greater (P < 0.05) than dogs in all other groups. The left atrium/aort a (LA/Ao) ratio of Group A dogs was significantly higher (P < 0.05) than th at of dogs of Group B and BI. Using the couple of variables BW and LA, the logistic regression models were able to predict "non-development of AF" (wi th 92.3% probability) vs. "development of AF" (with 74% probability), and " maintaining sinus rhythm" (with 95.1% probability) vs. "development of AF" (with 86% probability). (C) 2000 Harcourt Publishers Ltd.