Left ventricular performance in atrial fibrillation in the elderly.
Ejection fraction was measured directly by a radionuclide method, and indirectly from systolic time intervals, in elderly patients in atrial fibrillation. Both methods show that the ejection fraction averages approximately 55% at mean ventricular rates of 50-70 beats/min and falls to 20% or below as mean rate increases to over 120 beats/min. Atrial fibrillation is thus associated with a decrease in left ventricular performance, which is accentuated by increasing ventricular rates.
D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology*; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D005082:Physical Exertion; D013599:Systole