scholarly journals Models of Variability and Circadian Rhythm in Heart Rate, Blood Pressure, and QT Interval for Healthy Subjects Who Received Placebo in Phase I Trials

2019 ◽  
Vol 12 (5) ◽  
pp. 470-480 ◽  
Author(s):  
Mukul Minocha ◽  
Hong Li ◽  
Yi‐Lin Chiu ◽  
David Carter ◽  
Ahmed A. Othman
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Circadian Rhythm ◽  
Phase I ◽  
Qt Interval ◽  
Healthy Subjects ◽  
Phase I Trials

Circadian rhythm of the QT interval dispersion in healthy subjects. Correlation with heart rate variability circadian pattern

2005 ◽  
Vol 38 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Andrzej Biłan ◽  
Agnieszka Witczak ◽  
Robert Palusiński ◽  
Andrzej Ignatowicz ◽  
Janusz Hanzlik
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Circadian Rhythm ◽  
Qt Interval ◽  
Healthy Subjects ◽  
Circadian Pattern ◽  
Qt Interval Dispersion ◽  
Interval Dispersion

Influence of ageing on circadian rhythm of heart rate variability in healthy subjects

2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Agostino Accardo ◽  
Marco Merlo ◽  
Giulia Silveri ◽  
Lucia Del Popolo ◽  
Luca Dalla Libera ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Circadian Rhythm ◽  
Healthy Subjects

scholarly journals Cortisol Levels and Autonomic Control of Heart Rate in Healthy Subjects

2017 ◽  
Vol 17 (2) ◽  
pp. 5-14 ◽  
Author(s):  
Milana Drumond Ramos Santana ◽  
Eli Carlos Martiniano ◽  
Larissa Raylane Lucas Monteiro ◽  
Maria Do Socorro Santos De Oliveira ◽  
Vitor E. Valenti ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Salivary Cortisol ◽  
Healthy Subjects ◽  
Autonomic Control ◽  
Autonomic Modulation ◽  
Cardiac Autonomic Modulation ◽  
Cortisol Levels ◽  
Modulation Methods

AbstractIntroduction: There is an increase in level of stress in the general population because of the social, personal and professional demands. Currently, there are only simple tools that can safely measure this stress such as levels of cortisol and heart rate variability (HRV). Objective: To analyze the relationship between salivary cortisol and the cardiac autonomic modulation. Methods: A total of fifty-one male and female subjects between 18 and 40 years old were evaluated. Saliva collection was achieved for the salivary cortisol dosage. The collection was performed through the SalivetteR tube. After this collection, the median cortisol levels (0.24 ug/dl) were analyzed and the volunteers were divided into two groups: i) cortisol below the mediane ii) cortisol above the median. After this division, each group consisted of 25 volunteers and then was verified the following information: age, gender, weight, height, body mass index (BMI), blood pressure. Shortly thereafter was assessment of cardiac autonomic modulation por meio da HRV. The Polar RS800cx heart rate receiver was placed on the chest of the volunteers, in the vicinity of the distal third of the sternum. The volunteers were instructed to remain in rest with spontaneous breathing in dorsal position for 20 minutes. HRV analysis included geometric, time and frequency domain indices. Results: There were no statistical differences for the two groups regarding systolic and diastolic blood pressure, heart rate, RR intervals or linear and frequency indices for the volunteers. In addition, also there was no correlation the cortisol with the analyzed variables (SAP, p=0.460; DAP, p = 0.270; HR, p = 0.360; RR, p = 0.380; SDNN, p = 0.510; rMSSD, p = 0.660; pNN50, p = 0.820; RRtri, p = 0.170; TINN, p = 0.470; SD1, p = 0.650; SD2, p = 0.500; LF [ms2], p = 0.880; LF [nu], p = 0.970; HF [ms2], p = 0.870; HF [nu], p = 0.960; LF/HF, p = 0.380 Conclusion: Heart rate variability autonomic control was unchanged in healthy subjects with physiological distribution of salivary cortisol levels. There was no association between normal salivary cortisol and resting autonomic regulation of heart rate.

scholarly journals Associations between Intrinsic Heart Rate, P Wave and QT Interval Durations and Pulse Wave Analysis in Patients with Hypertension and High Normal Blood Pressure

2020 ◽  
Vol 17 (12) ◽  
pp. 4350
Author(s):  
Ioana Mozos ◽  
Cristina Gug ◽  
Costin Mozos ◽  
Dana Stoian ◽  
Marius Pricop ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Qt Interval ◽  
Pulse Wave ◽  
Pulse Wave Analysis ◽  
P Wave ◽  
Normal Blood Pressure ◽  
Wave Analysis ◽  
Wave Duration ◽  
P Wave Duration

The present study aimed to explore the relationship between electrocardiographic (ECG) and pulse wave analysis variables in patients with hypertension (HT) and high normal blood pressure (HNBP). A total of 56 consecutive, middle-aged hypertensive and HNBP patients underwent pulse wave analysis and standard 12-lead ECG. Pulse wave velocity (PWV), heart rate, intrinsic heart rate (IHR), P wave and QT interval durations were as follows: 7.26 ± 0.69 m/s, 69 ± 11 beats/minute, 91 ± 3 beats/minute, 105 ± 22 mm and 409 ± 64 mm, respectively. Significant correlations were obtained between PWV and IHR and P wave duration, respectively, between early vascular aging (EVA) and P wave and QT interval durations, respectively. Linear regression analysis revealed significant associations between ECG and pulse wave analysis variables but multiple regression analysis revealed only IHR as an independent predictor of PWV, even after adjusting for blood pressure variables and therapy. Receiver-operating characteristic (ROC) curve analysis revealed P wave duration (area under curve (AUC) = 0.731; 95% CI: 0.569–0.893) as a predictor of pathological PWV, and P wave and QT interval durations were found as sensitive and specific predictors of EVA. ECG provides information about PWV and EVA in patients with HT and HNBP. IHR and P wave durations are independent predictors of PWV, and P wave and QT interval may predict EVA.

scholarly journals Diurnal Corrected QT Interval and QT Dispersion Variation in Non-Alcoholic Cirrhotic Patients and Healthy Control: A Case-Control Study, Iran

2020 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Taghi Amiriani ◽  
Vahid Khori ◽  
Ali Davarian ◽  
Niloofar Rajabli ◽  
Mahsa Niknam ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Diurnal Variation ◽  
Healthy Subjects ◽  
Alcoholic Cirrhosis ◽  
Qt Dispersion ◽  
Qtc Interval ◽  
Healthy Controls ◽  
Cirrhotic Patients ◽  
The Mean

Background: Cirrhosis could lead to a long corrected QT (QTc) interval in a subgroup of patients, but there are spare data on its diurnal variation. Objectives: The present study aimed to determine the diurnal variation of QTc interval and its relationship to heart rate and blood pressure variation during 24-hour Holter-monitoring in non-alcoholic cirrhosis in comparison with the healthy controls. Methods: The study population comprised 15 patients with non-alcoholic cirrhosis and 15 healthy subjects, undergoing 24-hour electrocardiogram (ECG), heart rate, and blood pressure monitoring. The mean QT interval, mean QTc, maximum and minimum QT, QT dispersion (QT disp), heart rate, and mean arterial blood pressure were measured for each person for 24 hours. Liver stiffness measurement (LSM) was performed by FibroScan® 502 machine (EchoSense, Paris, France, 5 MHz). The results were demonstrated as percentages and mean ± SD. P value ≤ 0.05 was considered significant. Results: Mean QTc was significantly higher in cirrhosis (438 ms) than healthy controls (401.7 ms) (P = 0.03). The mean heart rate was significantly different in cirrhotic patients (79.6 ± 2.9/bpm) compared to healthy controls (72.47 ± 2.0/bpm) (P = 0.05). Conclusions: In this study, QTc was prolonged and increased with the severity of cirrhosis, and its diurnal variation in cirrhosis was different from healthy subjects.

Age dependency of cardiovascular autonomic responses to head-up tilt in healthy subjects

2004 ◽  
Vol 96 (6) ◽  
pp. 2333-2340 ◽  
Author(s):  
Tomi Laitinen ◽  
Leo Niskanen ◽  
Ghislaine Geelen ◽  
Esko Länsimies ◽  
Juha Hartikainen
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
High Frequency ◽  
Healthy Subjects ◽  
Baroreflex Sensitivity ◽  
Low Frequency ◽  
Upright Position ◽  
Vascular Responses ◽  
Autonomic Responses ◽  
Head Up Tilt

In elderly subjects, heart rate responses to postural change are attenuated, whereas their vascular responses are augmented. Altered strategy in maintaining blood pressure homeostasis during upright position may result from various cardiovascular changes, including age-related cardiovascular autonomic dysfunction. This exploratory study was conducted to evaluate impact of age on cardiovascular autonomic responses to head-up tilt (HUT) in healthy subjects covering a wide age range. The study population consisted of 63 healthy, normal-weight, nonsmoking subjects aged 23–77 yr. Five-minute electrocardiogram and finger blood pressure recordings were performed in the supine position and in the upright position 5 min after 70° HUT. Stroke volume was assessed from noninvasive blood pressure signals by the arterial pulse contour method. Heart rate variability (HRV) and systolic blood pressure variability (SBPV) were analyzed by using spectral analysis, and baroreflex sensitivity (BRS) was assessed by using sequence and cross-spectral methods. Cardiovascular autonomic activation during HUT consisted of decreases in HRV and BRS and an increase in SBPV. These changes became attenuated with aging. Age correlated significantly with amplitude of HUT-stimulated response of the high-frequency component ( r = -0.61, P < 0.001) and the ratio of low-frequency to high-frequency power of HRV ( r = -0.31, P < 0.05) and indexes of BRS (local BRS: r = -0.62, P < 0.001; cross-spectral baroreflex sensitivity in the low-frequency range: r = -0.38, P < 0.01). Blood pressure in the upright position was maintained well irrespective of age. However, the HUT-induced increase in heart rate was more pronounced in the younger subjects, whereas the increase in peripheral resistance was predominantly observed in the older subjects. Thus it is likely that whereas the dynamic capacity of cardiac autonomic regulation decreases, vascular responses related to vasoactive mechanisms and vascular sympathetic regulation become augmented with increasing age.

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