Cardiac fibrillation in batrachia
H. Mazzella 1
1 Departamento de Fisiologia, Facultad de Medicina, Montevideo, Uruguay
A study was made of fibrillation and its production in the heart of the toad (Bufo arenarum). Application of a strong electric shock during the interval of the T wave, or just before, produced fibrillatory response in the ventricle. Repetitive stimuli were necessary for production of fibrillation in the auricle. Fibrillation was of a coarse type but at 37°C it occurred more readily and resembled more nearly that of the mammalian heart. At 5°C the opposite effect occurred. Perfusion of the heart with high K+ solution reduced vulnerability while in low K+ fibrillation occurred more readily. Absence of Ca++ shortened durations of induced fibrillations. Changes in mechanical responses were compared with changes in electrograms.
Submitted on May 4, 1959
