Abstract
Patients with posttraumatic stress disorder (PTSD) have elevated sympathetic nervous system reactivity and impaired sympathetic and cardiovagal baroreflex sensitivity (BRS). Device-guided slow breathing (DGB) has been shown to lower blood pressure (BP) and sympathetic activity in other patient populations. We hypothesized that DGB acutely lowers BP, heart rate (HR), and improves BRS in PTSD. In 23 prehypertensive veterans with PTSD, we measured continuous BP, ECG, and muscle sympathetic nerve activity (MSNA) at rest and during 15 min of DGB at 5 breaths/min (n = 13) or identical sham device breathing at normal rates of 14 breaths/min (sham; n = 10). Sympathetic and cardiovagal BRS was quantified using pharmacological manipulation of BP via the modified Oxford technique at baseline and during the last 5 min of DGB or sham. There was a significant reduction in systolic BP (by -9 ± 2 mmHg, P < 0.001), diastolic BP (by -3 ± 1 mmHg, P = 0.019), mean arterial pressure (by -4 ± 1 mmHg, P = 0.002), and MSNA burst frequency (by -7.8 ± 2.1 bursts/min, P = 0.004) with DGB but no significant change in HR (P > 0.05). Within the sham group, there was no significant change in diastolic BP, mean arterial pressure, HR, or MSNA burst frequency, but there was a small but significant decrease in systolic BP (P = 0.034) and MSNA burst incidence (P = 0.033). Sympathetic BRS increased significantly in the DGB group (-1.08 ± 0.25 to -2.29 ± 0.24 bursts·100 heart beats -1 ·mmHg -1 , P = 0.014) but decreased in the sham group (-1.58 ± 0.34 to –0.82 ± 0.28 bursts·100 heart beats -1 ·mmHg -1 , P = 0.025) (time × device, P = 0.001). There was no significant difference in the change in cardiovagal BRS between the groups (time × device, P = 0.496). DGB acutely lowers BP and MSNA and improves sympathetic but not cardiovagal BRS in prehypertensive veterans with PTSD. NEW & NOTEWORTHY Posttraumatic stress disorder is characterized by augmented sympathetic reactivity, impaired baroreflex sensitivity, and an increased risk for developing hypertension and cardiovascular disease. This is the first study to examine the potential beneficial effects of device-guided slow breathing on hemodynamics, sympathetic activity, and arterial baroreflex sensitivity in prehypertensive veterans with posttraumatic stress disorder.
| Original language | English (US) |
|---|---|
| Pages (from-to) | H141-H149 |
| Journal | American Journal of Physiology - Heart and Circulatory Physiology |
| Volume | 315 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jul 2018 |
| Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by United States Department of Veterans Affairs Clinical Sciences Research and Development Program Merit Review Award I01CX001065 (to J. Park); American Heart Association National Affiliate Collaborative Sciences Award 15CSA24340001; resources and the use of facilities at the Clinical Studies Center of the Atlanta Veterans Affairs Medical Center; the Atlanta Research and Education Foundation; National Institutes of Health (NIH) Training Grant T32-DK-00756; Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development and the Clinical Studies Center (Decatur, GA); the Atlanta Research and Education Foundation; a University Research Council grant from Emory University; and the Atlanta Clinical and Translational Science Institute supported by NIH Grant UL1-RR-025008.
Publisher Copyright:
© 2018 American Physiological Society. All rights reserved.
Keywords
- Baroreflex
- Device-guided slow breathing
- Posttraumatic stress disorder
- Prehypertension
- Sympathetic nervous system
