Sung Ho Lee1, Ji Hyun Yang2, Hye Ran Yim3, Jungwae Park3, Seung-Jung Park3, Kyoung-Min Park3, Young Keun On3, June Soo Kim3. 1. Division of Cardiology, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. 2. Korea Association of Health Promotion, Seoul, Republic of Korea. 3. Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Abstract
BACKGROUND: We aimed to investigate differences in hemodynamic parameters and the role of baroreflex sensitivity (BRS) in patients with a history of neurally mediated syncope (NMS) compared with a control group. METHODS: Hemodynamic parameters and BRS were continuously measured noninvasively using a Finometer at rest and during passive head-up tilt test (HUT) in patients with a history of NMS (n = 55) and a control group (n = 77). The tilting period was divided into pretest (resting supine position), initial (first 3 minutes of tilting), last (last 3 minutes of tilting), and recovery (3 minutes after tilting was complete) periods. RESULTS: Decrease in systolic blood pressure (- 14.7 ± 15.7 mm Hg vs - 7.6 ± 14.3 mm Hg, P < 0.01) was more prominent and increase in total systemic peripheral resistance was significantly smaller (67.6 ± 418.7 dyn.s/cm5 vs 189.4 ± 261.0 dyn.s/cm5 , P = 0.04) from the initial to the last period of HUT in the patient group compared with the control group. BRS was significantly higher during the pretest period (20.1 ± 10.9 ms/mm Hg vs 13.0 ± 8.1 ms/mm Hg, P < 0.01) in the patient group, while the decrease in BRS from the pretest to the initial period was greater (-8.5 ± 6.0 ms/mm Hg vs - 3.2 ± 4.1 ms/mm Hg, P = 0.01). CONCLUSIONS: Dysfunctional BRS in response to orthostatic stress might be involved in pathological autonomic cardiac modulation of NMS.
BACKGROUND: We aimed to investigate differences in hemodynamic parameters and the role of baroreflex sensitivity (BRS) in patients with a history of neurally mediated syncope (NMS) compared with a control group. METHODS: Hemodynamic parameters and BRS were continuously measured noninvasively using a Finometer at rest and during passive head-up tilt test (HUT) in patients with a history of NMS (n = 55) and a control group (n = 77). The tilting period was divided into pretest (resting supine position), initial (first 3 minutes of tilting), last (last 3 minutes of tilting), and recovery (3 minutes after tilting was complete) periods. RESULTS: Decrease in systolic blood pressure (- 14.7 ± 15.7 mm Hg vs - 7.6 ± 14.3 mm Hg, P < 0.01) was more prominent and increase in total systemic peripheral resistance was significantly smaller (67.6 ± 418.7 dyn.s/cm5 vs 189.4 ± 261.0 dyn.s/cm5 , P = 0.04) from the initial to the last period of HUT in the patient group compared with the control group. BRS was significantly higher during the pretest period (20.1 ± 10.9 ms/mm Hg vs 13.0 ± 8.1 ms/mm Hg, P < 0.01) in the patient group, while the decrease in BRS from the pretest to the initial period was greater (-8.5 ± 6.0 ms/mm Hg vs - 3.2 ± 4.1 ms/mm Hg, P = 0.01). CONCLUSIONS: Dysfunctional BRS in response to orthostatic stress might be involved in pathological autonomic cardiac modulation of NMS.