Increases in Cardiac Output and Oxygen Consumption During Enhanced External Counterpulsation.
BACKGROUND
Regular enhanced external counterpulsation (EECP) improves exercise capacity possibly through a training effect, but the roles of oxygen consumption (VO2) vs. direct EECP effects (diastolic augmentation, DA-ratio), and their relation to cardiac index (CI) during EECP are unknown.


METHODS
We studied eight patients with angina pectoris (median [range] age 72 [53-85], 25% women), who underwent EECP for 35 daily sessions. Before, during and after the first and last sessions, we assessed VO2, DA-ratio and CI.


RESULTS
At first EECP, CI increased from 2.2 (1.7-2.9) L/min/m2prior to EECP to 3.0 (2.2-3.8) during EECP (p=0.011), and returned to 2.4 (0.8-3.0). Similarly, VO2increased during EECP and returned to baseline after EECP. These patterns were reproduced at the last EECP session. Absolute values of CI and VO2correlated with each other during but not prior to or after EECP. The increase in CI correlated with the increase in VO2by trend: (first session, r 0.52, p=0.19; second session r 0.69, p=0.09), but not with DA-ratio.


CONCLUSIONS
Acutely during EECP, there is an increase in cardiac output that is unrelated to direct EECP effects but related to, and may be secondary to, an increase in peripheral O2demand. This may represent a training effect.
Karolinska Institutet, School of Medicine, Stockholm, Sweden.
Magnus
M
Ahlbom
Karolinska University Hospital, Department of Cardiology, Stockholm, Sweden; Karolinska Institutet, Department of Medicine, Stockholm, Sweden.
Inger
I
Hagerman
Karolinska University Hospital, Department of Cardiology, Stockholm, Sweden; Karolinska Institutet, Department of Medicine, Stockholm, Sweden.
Marcus
M
Ståhlberg
Karolinska University Hospital, Department of Cardiology, Stockholm, Sweden; Karolinska Institutet, Department of Medicine, Stockholm, Sweden.
Aristomenis
A
Manouras
Karolinska University Hospital, Department of Cardiology, Stockholm, Sweden.
Gunilla
G
Förstedt
Karolinska University Hospital, Department of Cardiology, Stockholm, Sweden.
Eline
E
Wu
Karolinska University Hospital, Department of Cardiology, Stockholm, Sweden; Karolinska Institutet, Department of Medicine, Stockholm, Sweden. Electronic address: Lars.Lund@alumni.duke.edu.
Lars H
LH
Lund
D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000097:blood / Q000503:physiopathology / Q000628:therapy; D002302:Cardiac Output; D015908:Counterpulsation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption
D010100:Oxygen
Angina pectoris; Cardiac output; Diastolic augmentation; Enhanced external counterpulsation; Heart failure; Oxygen consumption