Morphological changes in atrial appendages removed during the maze procedure: a comparison with autopsy controls

Atrial fibrillation (AF) is commonly encountered in clinical practice and typically it is treated with pharmacological agents. Some patients whose arrhythmias are resistant to pharmacological therapy undergo the maze procedure, which is a surgical treatment. The atrial appendages are removed as part of the surgical procedure. These appendages often demonstrate mycocyte hypertrophy, vacuolar degeneration and other changes that may be seen in cardiomyopathies. We examined 19 of these appendages and compared them with 17 autopsy controls, 12 of whom had documented coronary atherosclerotic disease and 5 of whom did not. We semiquantitatively measured the amount of vacuolar degeneration, interstitial fibrosis, myocyte hypertrophy and intramyocardial adipose tissue. Univariate and multivariate analysis was performed and revealed that vacuolar degeneration were significantly more common in appendages of patients with arrhythmias than the autopsy controls (P<.0004). The other three histological features studied were not significantly different in the three groups. Ultrastructural studies on atrial tissue excised during the maze procedure, retrieved from the paraffin blocks, revealed degenerative changes similar to cardiomyopathic myocardial tissue. Vacuolar degeneration is commonly seen in atrial appendages removed in patients with chronic AF. Myocyte hypertrophy is a nonspecific finding and may occur in patients with arrhthymias and coronary artery disease.