The Valsalva manoeuvre as a cardiovascular reflex test in healthy children and teenagers.

The objective of this study was to determine whether the Valsalva manoeuvre is applicable as a test for neurocardiovascular control in healthy children and teenagers. Sixty-eight 6- to 16-year-old children and teenagers performed two Valsalva manoeuvres in the sitting position. They were instructed to maintain airway pressure (strain) for 15 s at 30 mmHg in the first and at 40 mmHg in the second manoeuvre. Finger arterial pressure and heart rate were monitored continuously. In three of the 68 subjects it was not possible to obtain a reliable blood pressure recording due to movements of the finger and/or hand. Only 10 subjects were able to reach a strain of 30 mmHg and to maintain this strain constant during 15 s; in the others the level or the duration of the strain varied substantially. Nine subjects kept strain at 40 mmHg during 15 s. With a Valsalva manoeuvre of 30 mmHg, control values of blood pressure and heart rate in the last 5 s prior to the manoeuvre increased in 11 subjects. Notwithstanding the large range in straining (15-55 mmHg), on visual inspection blood pressure and heart rate responses known from studies in adults could be recognized in 57 of the 65 subjects. In the other eight subjects atypical heart rate responses were observed. Forty-four of the 65 subjects could perform a Valsalva manoeuvre with a higher airway pressure compared to the first manoeuvre: range 35-55 mmHg. The higher airway pressure resulted in more pronounced blood pressure and heart rate responses. There was no correlation between age and gender versus airway pressure. It was concluded that the Valsalva manoeuvre generated blood pressure responses as found in adults. Heart rate responses were sometimes atypical, and needed underlying blood pressure measurement for full interpretation. For quantitative analysis the test was hampered by the inability of the majority of our young subjects to produce the exact strain during the 15-s period. Qualitatively, however, the Valsalva manoeuvre seems applicable as a cardiovascular reflex test to assess neurocardiovascular control in children and teenagers.