Valsalva Maneuver in Pulmonary Arterial Hypertension: Susceptibility to Syncope and Autonomic Dysfunction.
Chest. 2016 Jan 13;
Authors: Mar PL, Nwazue V, Black BK, Biaggioni I, Diedrich A, Paranjape SY, Loyd JE, Hemnes AR, Robbins IM, Robertson D, Raj SR, Austin ED
BACKGROUND: Primary arterial hypertension (PAH) patients are routinely instructed to avoid performing the Valsalva maneuver for fear of syncope or sudden cardiac death. The mechanism of this has not been elucidated. We conducted a case-control trial of 9 PAH patients and 15 healthy controls to determine if systemic hemodynamic changes during the Valsalva maneuver in PAH patients invoke greater susceptibility to syncope than healthy controls using metrics commonly employed in autonomic testing to assess degree of autonomic failure.
METHODS: Common Valsalva parameters including adrenergic baroreflex sensitivity, pressure recovery time, systolic blood pressure (SBP) recovery, diastolic blood pressure (DBP) recovery, mean arterial pressure (MAP) recovery, and the Valsalva ratio were calculated. Mann-Whitney U-tests were used to compare continuous variables. The primary end point was adrenergic baroreflex sensitivity.
RESULTS: PAH patients had lower adrenergic baroreflex sensitivity (9.7±4.6 vs 18.8±9.2 mmHg/second, P = 0.005), longer pressure recovery time (3.6±2.5 vs 1.7±0.8 seconds, P=0.008), similar SBP recovery (-13±11vs -12±23 mmHg, P = 0.640), less DBP recovery (-1±12 vs 13±14 mmHg, P = 0.025), less MAP recovery (-5±11 vs 5±17 mmHg, P = 0.048), and a decreased Valsalva ratio (1.25±0.11 vs 1.60±0.22, P < 0.001) compared to healthy controls.
CONCLUSION: Compared to healthy controls, PAH patients are more susceptible to syncope during the Valsalva maneuver due to autonomic dysfunction causing cerebral hypoperfusion. Our PAH patients exhibited a degree of susceptibility to syncope similar to a spectrum of patients with intermediate autonomic failure, who typically experience a SBP drop of 10-30 mmHg with standing.
PMID: 26836906 [PubMed - as supplied by publisher]