(960.8) Spontaneous Cardiovagal Baroreflex Sensitivity in Females with Multiple Sclerosis

Poster Board Number: E625

Claire Trotter (Southern Methodist University), Caitlin Jarrard (University of Texas Southwestern Medical Center), Alex Smith (Southern Methodist University), Helena Knoll (Southern Methodist University), Benjamin Young (University of Texas Southwestern Medical Center), Mu Huang (University of Texas Southwestern Medical Center), Scott Davis (Southern Methodist University)

Multiple sclerosis (MS) is a progressive demyelinating disease of the central nervous system that is known to disrupt autonomic function. Females with MS are at an increased risk of cardiovascular disease partly due to altered autonomic regulation of arterial blood pressure. Longitudinal data suggest that low spontaneous cardiovagal baroreflex sensitivity is a predictor of cardiovascular disease. Therefore, the purpose of this investigation is to test the hypothesis that spontaneous cardiovagal baroreflex sensitivity (cBRS) is less in females with MS compared to healthy controls. Electrocardiogram (ECG) and beat-to-beat blood pressure (Finometer) were continuously recorded during 10 minutes of quiet supine rest in 3 females with relapsing-remitting MS (Expanded Disability Scale Score lt; 6.0) and 3 sex-, age-, height-, weight- and race- matched healthy controls. Spontaneous cBRS was determined using the sequence method (CardioSeries v2.7). Spontaneous cBRS gain is calculated as the average slope of the relationship between R-R interval and systolic blood pressure from individual sequences of 3 or more consecutive cardiac cycles where both variables are increasing (up-up sequences) or decreasing (down-down sequences). Females with MS had similar resting mean arterial pressures (P=0.55), systolic blood pressures (P=0.53) and heart rates (P=0.18) compared to healthy controls. Overall spontaneous cBRS gain was greater in females with MS compared to healthy controls (27.1 ± 6.3 ms/mmHg vs. 18.8 ± 1.1 ms/mmHg respectively; P=0.04). Spontaneous cBRS gain from up-up sequences was also greater in females with MS compared to healthy controls (27.6 ± 5.1 ms/mmHg vs. 17.1 ± 2.1 ms/mmHg respectively; P=0.01). Spontaneous cBRS gain from down-down sequences trended to be greater in females with MS compared to healthy controls but was not statistically significant (27.2 ± 7.8 ms/mmHg vs. 20.1 ± 2.4 ms/mmHg respectively; P=0.10). Counter to our hypothesis, these preliminary findings in a small sample suggest that females with MS have increased spontaneous cBRS compared to healthy controls. If this relationship continues with additional data collection, it may indicate that females with MS have enhanced cardiac responses to regulate arterial blood pressure.

Support or Funding Information

American College of Sports Medicine Doctoral Research Grant (grant no. 19-01141)