A call to reevaluate cardiac autonomic assessment after spinal cord injury.

This "Perspectives" article puts forward the notion that measuring heart rate variability, or other forms of cardiac autonomic regulation, after spinal cord injury must be performed during a test of autonomic stress. Resting values of heart rate variability are often similar to those obtained from able-bodied individuals, which may therefore be falsely interpreted as normal or healthy autonomic regulation. However, evidence shows that despite normal resting values, cardiac autonomic control is impaired when individual with spinal cord injury are subjected to a cold face test, head-up tilt, or recovery from exercise. Accordingly, examination of cardiac autonomic function must be performed during an autonomic challenge, as resting measures do not accurately reflect the state of cardiovascular regulation after spinal cord injury and can provide false information.