Survival time in dogs with spontaneous atrial fibrillation related to scintigraphically measured cardiac performance.

In 40 canine patients with spontaneous atrial fibrillation (AF) cardiac performance was measured scintigraphically and correlated with the survival time (ST) following the diagnosis of AF. The parameters used for cardiac performance were heart rate (HR), end-diastolic left ventricular volume (EDV), ejection fraction of the left ventricle (EF), left ventricular regurgitation fraction (RF) and cardiac output (CO). ST varied from 3 days to 780 days. Two groups of animals were distinguished as previously described: group A (EF less than 0.3, n = 26) and group B (EF greater than or equal to 0.3, n = 14). The median ST (90 days) in group A was only weakly significant (p = 0.1) shorter than in group B (150 days). RF was significantly lower in group A than in group B (p less than 0.001). A weak correlation was found between ST and EF (r = 0.28; p = 0.04). It was concluded that the prognosis in the described AF patients is slightly favourable if EF is normal or only moderately reduced.