Standing Under Pressure: Hemodynamic Effects of Abdominal Compression Type and Intensity in Healthy Adults

Kishen Mitra¹Sameer Kunte²Sara E Taube¹Shruthee Sankarlinkam¹Liban Mohamed²Eghosa Adodo²Cynthia L Green^3,4Marat Fudim^2,4Eric S Richardson^1*

• ¹Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina, United States
• ²Duke University Medical Center, Duke University, Durham, North Carolina, United States
• ³Department of Biostatistics and Bioinformatics, School of Medicine, Duke University, Durham, North Carolina, United States
• ⁴Duke Clinical Research Institute, School of Medicine, Duke University, Durham, North Carolina, United States

Introduction: Abdominal compression is recommended to manage orthostatic intolerance in dysautonomia, but the hemodynamic effects of different compression parameters remain poorly understood. This study investigated how surface area and pressure magnitude of abdominal compression affect blood pressure and heart rate responses during active standing tests in healthy volunteers. Understanding how abdominal compression modulates hemodynamics during standing in healthy individuals will help us better understand how compression can be optimized to benefit those with dysautonomia.Methods: Two compression devices were developed: one applying circumferential pressure (40 mmHg) over a higher surface area (HSA), and another applying focal pressure to the epigastrium at either 95 mmHg (LSA-LP) or 140 mmHg (LSA-HP). Forty-seven healthy participants completed randomized 3-minute active standing tests with each device and a control condition. Heart rate was measured immediately upon standing (0 min) and at 15 sec, 30 sec, 1 min, 2 min, and 3 min afterward. Blood pressure was measured at 1-minute intervals. All measurements were normalized to supine baseline values and presented as mean ± SEM.Results: All compression modalities significantly reduced the initial heart rate increase immediately upon standing compared to control (HSA: -2.0±1.1 bpm, LSA-LP: 1.8±1.0 bpm, LSA-HP: 2.7±1.7 bpm vs. control: 6.0±1.2 bpm; all p<0.01). HSA compression showed greater hemodynamic effects than LSA-LP, with a significantly lower normalized heart rate at 0 min (p=0.031). HSA compression was associated with higher systolic blood pressure compared to control at 3 minutes (7.2±0.9 vs. 3.6±0.9 mmHg; p=0.006), and LSA-HP at 1 minute (7.2±1.0 vs. 3.8±1.5 mmHg; p=0.049). No significant differences were found between LSA-HP and LSA-LP across any timepoint. Discussion: Surface area appears to be a more critical factor than pressure magnitude in stabilizing hemodynamics during orthostatic stress, with significant effects observed immediately upon standing. These findings provide physiological insights for optimizing compression therapy in orthostatic disorders and suggest that wider-area compression garments may offer superior hemodynamic benefits compared to focal compression.