Pathology of atrial fibrillation in man.

Abstract

Quantitative studies on the sinoatrial (SA) node and internodal tracts in IOO heartsfrom patients coming to necropsy with atrialfibrillation have been carried out. In patients with atrialfibrillation developing only in the last two weeks of life, pulmonary emboli and acute pericarditis were common precipitating factors. Atrial dilatation was common but the SA node and internodal tracts were within normal limits. In contrast patients with long-term atrial fibrillation showed combinations of nodal artery stenosis, muscle loss in the SA node or internodal tracts, and atrial dilatation. The pathological conditions found most commonly were chronic rheumatic valve disease, ischaemic heart disease, hypertension, and cor pulmonale. Atrialfibrillation in some aged patients was associated with loss of muscle fibres in the SA node without any clear pathological cause.