Cardiac autonomic dysfunction in the early phase after left ventricular assist device implant: Implications for surgery and follow-up.

Purpose: In congestive heart failure (CHF) patients, a profound cardiac autonomic derangement, clinically expressed by reduced heart rate variability (HRV), is present and is related to the degree of ventricular dysfunction. Implantation of a left ventricular assist device (LVAD) can progressively improve HRV, associated with an increased circulatory output. Data from patients studied at different times after LVAD implantation are controversial.