WHAT ARE THE RISK-FACTORS FOR ARRHYTHMIAS AFTER THORACIC OPERATIONS -A RETROSPECTIVE MULTIVARIATE-ANALYSIS OF 267 CONSECUTIVE THORACIC OPERATIONS

Two hundred sixty-seven operations performed consecutively at the Nati onal Cancer Center Hospital, Tokyo, in 1990 were reviewed to define th e prevalence, type, clinical course, and, especially, risk factors for arrhythmias after thoracic operations. Arrhythmias were identified in 63 operations (23.6 %) and were more prevalent in several subgroups o f patients than in others-those with lung cancer, pneumonectomy, media stinal lymph node dissection, and those older than 70 years of age. Su praventricular tachycardias, of which atrial fibrillation was the most common, comprised 95.3 % of the cases; bradyarrhythmia and ventricula r ectopic beats were seen in only three and four cases, respectively. Arrhythmias were most likely to develop on the second day after the op eration. Eighty percent of the arrhythmias disappeared within 3 days a fter onset, and sinus rhythm was finally restored with digitalis or ot her antiarrhythmic drugs in all patients except one, who had a myocard ial infarction. Arrhythmias were not the direct cause of any of the se ven in-hospital deaths. A multivariate analysis of 16 variables reveal ed that age and extent of pulmonary resection were significant risk fa ctors. Despite these significant risk factors, arrhythmias after thora cic operations could be managed without special prophylaxis and were n ot closely related to higher mortality.