[Occurrence of persistent atrial fibrillation in acquired heart defects].

Functional relationship between hemodynamic overstrain and left-atrial distension was investigated in 209 patients with acquired heart diseases and developing persistent atrial fibrillation. The development of constant atrial fibrillation was shown to depend on the correlation between mean left-atrial pressure and size, and functional relations between the two parameters, i. e. their critical ratio at the time when constant fibrillation is established, were determined. The critical curves which define this relationship for males and females demonstrate that constant fibrillation develops in patients with high mean pressure in the left atrium that is only slightly distended, and in patients with lower mean pressure in a considerably distended left atrium.