Postoperative Modifications of Cardiovascular Control and Baroreflex Sensitivity in Patients Undergoing Surgical Aortic Valve Replacement

Time and frequency domains indexes derived from spontaneous fluctuations of heart period (HP) and systolic arterial pressure (SAP) and baroreflex sensitivity (BRS) are usually exploited to assess the state of the autonomic control. Surgical aortic valve replacement (SAVR) features postoperative complications, such as atrial fibrillation, that can be favored by an impairment of cardiovascular autonomic control. We computed HP and SAP variability markers in time and frequency domains and BRS via transfer function analysis in seven patients one day before (PRE) and 7 days after (POST) SAVR surgery. Indexes were assessed at rest in supine position (REST) and during active standing (STAND). No autonomic regulatory response to STAND was detected either in PRE or POST sessions. In POST at REST a remarkable depression of BRS indexes was observed compared to PRE, thus suggesting an increased risk for postoperative adverse events and prompting for the search of suitable countermeasures.