MEASUREMENT OF VENTRICULAR-FUNCTION BY ECG GATING DURING ATRIAL-FIBRILLATION

  • 1 January 1981
    • journal article
    • research article
    • Vol. 22  (3) , 226-231
Abstract
The assumptions necessary to perform ECG-gated cardiac studies are seemingly not valid for patients in atrial fibrillation (AF). To evaluate the effect of AF on equillibrium gated scintigraphy, beat-by-beat measurements of left-ventricular function were made on 7 subjects in AF (mean heart rate 64 bpm [beats/min]) using a high-efficiency nonimaging detector. The parameters evaluated were ejection fraction (EF), time to end-systole (TES), peak rates of ejection and filling (PER,PFR) and their times of occurrence (TPER,TPFR). By averaging together single-beat values of EF, PER, etc., it was possible to determine the true mean values of these parameters. The single-beat mean values were compared with the corresponding parameters calculated from 1 ECG-gated time-activity curve (TAC) obtained by superimposing all the single-beat TAC irrespective of their length. For this population with slow heart rates, the values for EF, etc., produced from ECG-gated time-activity curves, are very similar to those obtained from the single-beat data. Thus use of ECG gating at low heart rates may allow reliable estimation of average cardiac function even in subjects with AF.