The noninvasive evaluation of exercise-induced changes in pulmonary artery pressure and pulmonary vascular resistance.
BACKGROUND
During exercise, pulmonary artery systolic pressure (PASP) may increase. The purpose of this study was to examine the responses of PASP and pulmonary vascular resistance by Doppler echocardiography during exercise in conditioned athletes and in patients with pulmonary disease.


METHODS
Fifteen participants in each group were evaluated using Doppler echocardiography at rest and during recumbent bicycle exercise. PASP was calculated using 4 times the tricuspid regurgitant velocity squared (TRV)2 and a surrogate for pulmonary vascular resistance was calculated using the equation: pulmonary vascular resistance = TRV/right ventricular outflow tract time-velocity integral.


RESULTS
During exercise, PASP increased in both groups with higher values achieved by patients with pulmonary conditions (54.8 vs 70.6 mm Hg, P = .009). At baseline the ratio TRV/right ventricular outflow tract time-velocity integral was 0.2 or less in both the athlete and pulmonary groups. During exercise, the ratio of TRV/right ventricular outflow tract time-velocity integral remained less than 0.2 in the athletes and increased more than 0.2 in the pulmonary group.


CONCLUSIONS
Doppler echocardiography can be used to discriminate a flow- versus resistance-mediated mechanism for exercised-induced increase in PASP.
Bidart
Chad M
CM
Division of Cardiovascular Disease, Mayo Clinic Arizona, Scottsdale, Arizona, USA.
Abbas
Amr E
AE
Parish
James M
JM
Chaliki
Hari P
HP
Moreno
Carlos A
CA
Lester
Steven J
SJ
D000222:Adaptation, Physiological; D000328:Adult; D000368:Aged; D001794:Blood Pressure; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008173:Lung Diseases, Obstructive / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008297:Male; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D014463:Ultrasonography; D014655:Vascular Resistance