Sources of variation in cardiac output determined by the first-passage radionuclide technique were evaluated in 30 patients with coronary artery disease. In 12 fasting patients the standard deviations of differences in cardiac output measured three times with 1-hour intervals were 0.77 and 0.93 liters/min. No systematic variation was evident. An 8% reduction was demonstrated in cardiac output measured in 18 patients at 2-day intervals (p<0.01), possibly due to anxiety or discomfort at the first examination. The standard deviation of the day-to-day differences was 0.61 liters/min and thus not higher than that of the hour-to-hour differences. The standard deviation of differences between two-observer analysis was 0.34 liters/min, and a small difference of 3.7% was statistically significant (p<0.05). No significant intraobserver variation was found. Intraobserver differences had standard deviations of 0.34 and 0.48 liters/min. In patients with coronary artery disease, the first-passage radionuclide cardiac output accordingly varies considerably over time, but the precision of this technique is high.
|Tidsskrift||American Journal of Noninvasive Cardiology|
|Status||Udgivet - 1 jan. 1988|