Standing and exercise Doppler echocardiography in obstructive hypertrophic cardiomyopathy: the range of gradients with upright activity.
BACKGROUND
The ideal provocative maneuver in patients with hypertrophic cardiomyopathy (HCM) is a subject of ongoing investigation. Standing is a fundamental activity of daily life. This study examined acquisition of standing, Valsalva, and post-exercise left ventricular outflow tract gradients in HCM.


METHODS
Rest supine, standing, and post-Valsalva gradients were measured in 98 consecutive patients with HCM who were referred for outpatient echocardiography. In 53 (54%) of the 98 patients, symptom-limited treadmill exercise was also performed, with gradients measured immediately after in the supine position.


RESULTS
Fifty-six (57%) of the 98 patients had resting gradient<30 mm Hg and would thus be characterized as nonobstructive at rest. In the 98 patients, median gradients were 25 mm Hg at rest (range 0-205 mm Hg), increasing to 44 mm Hg after standing (range 0-309 mm Hg), an increase of 76%, and were again higher after Valsalva, 64 mm Hg (range 0-256 mm Hg) (P<.001). In the 53 patients who had gradient assessed after exercise, they were higher still, 100 mm Hg (range 0-256 mm Hg) (P<.001). In 29 patients (30%), standing provoked a higher gradient than Valsalva.


CONCLUSIONS
Although standing increased gradients by 76%, it is not as potent a provocative maneuver as Valsalva or treadmill exercise. Nevertheless, standing is recommended as a physiologic provocative maneuver. In some patients standing may guide therapy; in others, the standing and exercise gradient provide a correct appreciation of the range of physiologically experienced gradients during daily upright activity.
St. Luke's-Roosevelt Hospital Center, Columbia University, College of Physicians and Surgeons, New York, New York 10019, USA.
Sandeep
S
Joshi
Utpal K
UK
Patel
Siu-Sun
SS
Yao
Vilma
V
Castenada
April
A
Isambert
Glenda
G
Winson
Farooq A
FA
Chaudhry
Mark V
MV
Sherrid
D000203:Activities of Daily Living; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015150:Echocardiography, Doppler / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014636:Valsalva Maneuver