Influence of repetitions on the Valsalva maneuver

Abstract

Objective: In autonomic units, patients perform several short Valsalva maneuvers (VMs) while learning the procedure. The effects of repeated VMs on cardiovascular elicited responses were assessed. Methods: 14 healthy volunteer subjects were selected (aged 22-26). VMs were performed every 3 min up to 6 times in a reclined sitting position. Changes in blood pressure (BP), heart rate (HR) and baroreflex sensitivity indexes were evaluated. Subjects were classified according to their adrenergic response patterns. Results: VMs repetitions evoked a progressive decrease in BP during phases II and III and a reduced increase in mean BP at late phase II. Increased bradycardia at early phase II and IV was also observed. Last two VMs showed a significant increase in Valsalva ratio, while other indexes remained unaltered. Subjects with balanced adrenergic responses presented extended pressure recovery time from the third repetition and lower BP values than those with augmented or suppressed adrenergic responses. Conclusions: Significant changes in BP and HR at certain phases were observed when consecutive VMs were performed in young subjects in a reclined position. The most affected baroreflex index was the Valsalva ratio. Adrenergic response patterns showed differences that should be considered in order to avoid false positives. Significance: We recommend not repeating the VM more than 4 times and revisiting the role and reliability of the Valsalva ratio.