Aschoff bodies in operatively excised atrial appendages and in papillary muscles. Frequency and clinical significance.

Among 481 patients undergoing various mitral valve operations, Aschoff bodies were found in 40 (21%) of 191 operatively excised left atrial appendages, in four (2%) of 273 operatively excised left ventricular papillary muscles (1 per patient), and in one (6%) of 17 patients with both left atrial appendage and papillary muscle operatively excised. Of the total of 45 patients with Aschoff bodies, 44 preoperatively had mitral stenosis, and only one, a 10-year-old boy, had pure mitral regurgitation. Sinus rhythm was present in 38 (84%), and atrial fibrillation in seven (16%). Perioperatively, only one of the 45 patients with Aschoff bodies had clinical or laboratory stigmata compatible with acute rhematic fever, and 58% had an illness compatible with acute rheumatic fever at any time.