Background: Baseline low-to-high frequency ratio (LF/HF) of heart rate variability predicted hypotension after subarachnoid block (SAB). LF/HF-guided treatment of hypotension with vasopressors or colloids was investigated.
Methods: In 80 women scheduled to undergo cesarean delivery during SAB, LF/HF and systolic blood pressure (SBP) were analyzed. Patients were randomly assigned to a control group (n = 40) or a treatment group (n = 40). Control patients were assigned by their baseline LF/HF to one of two subgroups: LF/HF less than 2.5 or LF/HF greater than 2.5. Treatment patients with baseline LF/HF greater than 2.5 were treated with vasopressor infusion right after SAB (n = 20) or colloid prehydration until LF/HF decreased below 2.5 (n = 20). The incidences of hypotension (SBP < 80 mmHg) and hypertension (SBP > 140 mmHg) were investigated. LF/HF is presented as median and range, and SBP is presented as mean +/- SD.
Results: Three of 17 control patients with low baseline LF/HF (1.7 [1.3/1.8]) demonstrated hypotension, and mean SBP remained stable (lowest SBP = 105 +/- 14 mmHg). In contrast, 20 of 23 control patients with high baseline LF/HF (3.8 [3.3/4.8]; P < 0.0001 vs. low baseline LF/HF) demonstrated hypotension after SAB: lowest SBP = 78 +/- 15 mmHg (P < 0.0001 vs. lowest SBP of control group with low baseline LF/HF). LF/HF-guided vasopressor therapy prevented hypotension in 19 of 20 patients: baseline SBP = 123 +/- 15 mmHg, lowest SBP = 116 +/- 17 mmHg. Mean prophylactic colloid infusion of 1,275 +/- 250 ml reduced elevated baseline LF/HF from 5.4 (4.1/7.5) to 1.3 (0.8/1.59) (P < 0.0001). Hypotension was prevented in 17 of 20 patients: baseline SBP = 115 +/- 13 mmHg, lowest SBP = 104 +/- 19 mmHg. No hypertensive episode was recognized.
Conclusions: LF/HF may be a tool to guide prophylactic therapy of patients at high risk for hypotension after SAB. Vasopressor therapy tended to be more effective compared with colloid prehydration.
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http://dx.doi.org/10.1097/00000542-200604000-00005 | DOI Listing |
Clin Auton Res
January 2025
Exercise Research Laboratory (LAPEX), School of Physical Education, Physiotherapy and Dance, Federal University of Rio Grande do Sul, 750, Felizardo Street, Porto Alegre, RS, 90690-200, Brazil.
Purpose: The present review investigates the responses of heart rate variability indices following high-intensity interval aerobic exercise, comparing it with moderate-intensity continuous exercise in adults, with the aim of informing clinical practice.
Methods: Searches were conducted in four databases until March 2023. Eligible studies included randomized controlled trials that assessed heart rate variability indices such as the standard deviation of normal-to-normal heartbeat intervals (SDNN), the root mean square of successive differences (RMSSD), the proportion of the number of pairs of successive normal-to-normal (NN or R-R) intervals that differ by more than 50 ms (NN50) divided by the total number of NN intervals (pNN50), power in high frequency range (HF), power in low frequency range (LF), and LF/HF before and after high-intensity interval and moderate-intensity continuous aerobic exercise.
JAMA Surg
January 2025
Center for Surgery and Public Health, Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Importance: Surgeon stress can influence technical and nontechnical skills, but the consequences for patient outcomes remain unknown.
Objective: To investigate whether surgeon physiological stress, as assessed by sympathovagal balance, is associated with postoperative complications.
Design, Setting, And Participants: This multicenter prospective cohort study included 14 surgical departments involving 7 specialties within 4 university hospitals in Lyon, France.
J Clin Med
December 2024
Grupo de Investigación en Actividad Física Calidad de Vida y Salud (AFYCAV), Facultad de Ciencias del Deporte, Universidad de Extremadura, Avenida de la Universidad s/n, 10003 Cáceres, Spain.
People with fibromyalgia (FM) exhibit alterations in brain electrical activity and autonomic modulation compared to healthy individuals. : This study aimed to investigate transcranial direct current stimulation (tDCS) effects on brain electrocortical activity and heart rate variability (HRV), specifically targeting the dorsolateral prefrontal cortex in both healthy controls (HC) and FM groups, to identify potential differences in the responses between these groups, and to compare the effectiveness of two distinct tDCS intensities (1 mA and 2 mA) against a sham condition. : Electroencephalography and electrocardiogram signals were recorded pre- and post-tDCS intervention.
View Article and Find Full Text PDFFront Psychiatry
December 2024
Department of Psychiatry, Chonnam National University Medical School, Gwangju, Republic of Korea.
Introduction: This study examined the moderating effects of childhood abuse histories on the associations between low frequency (LF) and high frequency (HF) components of heart rate variability (HRV) and the development of post-traumatic stress disorder (PTSD).
Methods: Participants with physical injuries were recruited from a trauma center and followed for two years. Baseline assessments included LF, HF, and childhood abuse histories, assessed using the Nemesis Childhood Trauma Interview.
J Vet Intern Med
December 2024
Department of Veterinary Clinical Sciences, Washington State University, Pullman, Washington, USA.
Background: Fitness assessment of horses remains challenging. Heart rate variability (HRV) can be used to monitor human athlete's training, but its value is unknown in horses.
Hypothesis: The linear domain HRV variables are affected by fitness.
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