Noninvasive cardiac output monitoring during exercise stress test.
A computerized continuous wave Doppler instrument was used to monitor changes in cardiac output during symptom limited supine bicycle exercise in 41 individuals. Eight (19%) had technically unsatisfactory Doppler signals. Of the remaining 33 patients, 21 had clinical and 18 had angiographic evidence of coronary artery disease (group 1) and 12 age-matched asymptomatic subjects served as controls (group 2). In eight group 1 patients, cardiac output determined simultaneously by Doppler and thermodilution technique correlated well at rest and peak exercise (Y = 1.71x + 0.69, SEE = 0.57, r = 0.86, P less than 0.001). During exercise, group 1 patients increased their cardiac output from 5.2 +/- 1 to 6.9 +/- 1.4 (mean +/- SD), group 2 subjects increased their cardiac output from 5.5 +/- 1.3 to 10.9 +/- 2. Group 1 patients, when compared to group 2 control subjects, had a lesser increase in cardiac output (34% versus 103%, P less than 0.05), a shorter duration of exercise (6.1 versus 9.7 mins, P less than 0.05) and a lower double product (172 +/- 18 versus 211 +/- 27, P less than 0.05). This new Doppler technique provides reasonably accurate estimates of cardiac output at rest and on moderate exercise in selected patients. In selected clinical situations, it may be a valuable addition to other measurements that are usually determined during exercise.
Nanna
M
M
Department of Medicine, LAC-USC Medical Center, University of Southern California School of Medicine 90033.
Kawanishi
D T
DT
McKay
C R
CR
Rahimtoola
S H
SH
Nimalasuriya
A
A
Chandraratna
P A
PA
D002302:Cardiac Output; D003327:Coronary Disease / Q000175:diagnosis*; D004452:Echocardiography; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D005082:Physical Exertion; D013318:Stroke Volume