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 P P Conclusion 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.