Abstract Details

Title Assessment of Cardiovascular Adrenergic Function Using the Valsalva Maneuver - Reproducibility and Validity of Indices

Topic Autonomic Disorders

Presentation(s) P03 - (-)

Poster/Presentation
Number 020

Objective

Background BACKGROUND: The VM has a long tradition as integral component of standardized autonomic function testing. While heart rate responses to the VM provide information about cardiovagal integrity, blood pressure (BP) responses provide valuable information about cardiovascular adrenergic function. Various adrenergic indices derived from the VM have been described, but a comparative assessment is lacking.

Design/Methods DESIGN/METHODS: Using our autonomic research database, we randomly selected three age-matched groups of 30 subjects each: group one with severe adrenergic impairment, group two with mild to moderate adrenergic impairment, and group three comprising healthy control subjects. Adrenergic indices were derived for each subject from two technically adequate VMs as follows: BP drop and pulse pressure compression during early phase II, BP recovery during late phase II, BP overshoot during phase IV, BP recovery time (PRT), 50% PRT, and baroreflex sensitivity index calculated from PRT. Reproducibility and validity of each parameter were assessed using intra-class correlation analysis and nonparametric between group comparisons.

Results RESULTS: Highly significant within parameter correlations were seen for all indices, but the most reproducible parameters were BP recovery during late phase II, PRT, and BP drop during early phase II (ICC 0.95-0.98). Highly significant group differences were also seen for all parameters, with the best separation of groups achieved by BP recovery during late phase II as well as PRT. BP drop and pulse pressure compression during early phase II and parameters related to phase IV overshoot showed the most overlap between groups.

Conclusions CONCLUSIONS: Parameters used to assess adrenergic function derived from the VM show generally good reproducibility and validity, but notable differences among parameters exist. Superior parameters appear to be those assessing late phase II BP recovery and PRT.

Authors/Disclosures
Tonette Gehrking PRESENTER	Tonette Gehrking has nothing to disclose.
Jade Gehrking (Mayo Clinic, Neurology Dept)	Jade Gehrking has nothing to disclose.
Jayawant N. Mandrekar, PhD	Dr. Mandrekar has nothing to disclose.
Mitchell S. Elkind, MD, MS, FAAN	Dr. Elkind has received personal compensation for serving as an employee of American Heart Association. Dr. Elkind has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Atria Academy.
Phillip A. Low, MD, FAAN (Mayo Clinic)	Dr. Low has nothing to disclose.
Wolfgang Singer, MD, FAAN (Mayo Clinic)	Dr. Singer has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biohaven. The institution of Dr. Singer has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Lundbeck. Dr. Singer has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Ionis. Dr. Singer has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Yoda. Dr. Singer has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Theravance. Dr. Singer has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Ferrer. The institution of Dr. Singer has received research support from NIH. The institution of Dr. Singer has received research support from FDA. The institution of Dr. Singer has received research support from Michael J. Fox Foundation. Dr. Singer has received intellectual property interests from a discovery or technology relating to health care.

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