Abstract
Patients with severe calcific aortic valve stenosis have chronic sympathetic hyperactivity and a diminished increase in sympathetic activation when they change from supine position (resting) to active standing. In this work, we tested whether the change in heart rate variability indices, as a measure of cardiac autonomic modulation, was associated with complications or mortality after the patients had surgery to replace the aortic valve. We found that those who had complications or mortality after the surgery had a smaller change in their heart rate variability indices when standing, consistent with smaller sympathetic activation compared to those without complications or mortality. We discuss the physiological alterations that may lead to poor compensation of the sympathetic nervous system when the body faces the physiological challenge of standing up before surgery and how this could be tested in future studies as a potential predictor of complications or death after surgery.