scholarly journals Effects of Lifestyle Modification on Patients With Resistant Hypertension: Results of the TRIUMPH Randomized Clinical Trial

Circulation ◽  
2021 ◽  
Vol 144 (15) ◽  
pp. 1212-1226
Author(s):  
James A. Blumenthal ◽  
Alan L. Hinderliter ◽  
Patrick J. Smith ◽  
Stephanie Mabe ◽  
Lana L. Watkins ◽  
...  
Keyword(s):  
Heart Rate ◽  
Resistant Hypertension ◽  
High Frequency ◽  
Baroreflex Sensitivity ◽  
Pulse Wave ◽  
Lifestyle Modification ◽  
Left Ventricular ◽  
Flow Mediated Dilation ◽  
Disease Biomarkers ◽  
Diet And Exercise

Background: Although lifestyle modifications generally are effective in lowering blood pressure (BP) among patients with unmedicated hypertension and in those treated with 1 or 2 antihypertensive agents, the value of exercise and diet for lowering BP in patients with resistant hypertension is unknown. Methods: One hundred forty patients with resistant hypertension (mean age, 63 years; 48% female; 59% Black; 31% with diabetes; 21% with chronic kidney disease) were randomly assigned to a 4-month program of lifestyle modification (C-LIFE [Center-Based Lifestyle Intervention]) including dietary counseling, behavioral weight management, and exercise, or a single counseling session providing SEPA (Standardized Education and Physician Advice). The primary end point was clinic systolic BP; secondary end points included 24-hour ambulatory BP and select cardiovascular disease biomarkers including baroreflex sensitivity to quantify the influence of the baroreflex on heart rate, high-frequency heart rate variability to assess vagally mediated modulation of heart rate, flow-mediated dilation to evaluate endothelial function, pulse wave velocity to assess arterial stiffness, and left ventricular mass to characterize left ventricular structure. Results: Between-group comparisons revealed that the reduction in clinic systolic BP was greater in C-LIFE (–12.5 [95% CI, –14.9 to –10.2] mm Hg) compared with SEPA(–7.1 [–95% CI, 10.4 to –3.7] mm Hg) ( P =0.005); 24-hour ambulatory systolic BP also was reduced in C-LIFE (–7.0 [95% CI, –8.5 to –4.0] mm Hg), with no change in SEPA (–0.3 [95% CI, –4.0 to 3.4] mm Hg) ( P =0.001). Compared with SEPA, C-LIFE resulted in greater improvements in resting baroreflex sensitivity (2.3 ms/mm Hg [95% CI, 1.3 to 3.3] versus –1.1 ms/mm Hg [95% CI, –2.5 to 0.3]; P <0.001), high-frequency heart rate variability (0.4 ln ms 2 [95% CI, 0.2 to 0.6] versus –0.2 ln ms 2 [95% CI, –0.5 to 0.1]; P <0.001), and flow-mediated dilation (0.3% [95% CI, –0.3 to 1.0] versus –1.4% [95% CI, –2.5 to –0.3]; P =0.022). There were no between-group differences in pulse wave velocity ( P =0.958) or left ventricular mass ( P =0.596). Conclusions: Diet and exercise can lower BP in patients with resistant hypertension. A 4-month structured program of diet and exercise as adjunctive therapy delivered in a cardiac rehabilitation setting results in significant reductions in clinic and ambulatory BP and improvement in selected cardiovascular disease biomarkers. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02342808.

Heart rate variability and baroreflex sensitivity are reduced in chronically undernourished, but otherwise healthy, human subjects

2003 ◽  
Vol 104 (3) ◽  
pp. 295-302 ◽  
Author(s):  
Mario VAZ ◽  
A.V. BHARATHI ◽  
S. SUCHARITA ◽  
D. NAZARETH
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Baroreflex Sensitivity ◽  
Human Subjects ◽  
Normal Weight ◽  
Autonomic Nerve ◽  
Total Power ◽  
Healthy Human ◽  
Frequency Power

Alterations in autonomic nerve activity in subjects in a chronically undernourished state have been proposed, but have been inadequately documented. The present study evaluated heart rate and systolic blood pressure variability in the frequency domain in two underweight groups, one of which was undernourished and recruited from the lower socio-economic strata [underweight, undernourished (UW/UN); n = 15], while the other was from a high class of socio-economic background [underweight, well nourished (UW/WN); n = 17], as well as in normal-weight controls [normal weight, well nourished (NW/WN); n = 27]. Baroreflex sensitivity, which is a determinant of heart rate variability, was also assessed. The data indicate that total power (0–0.4Hz), low-frequency power (0.04–0.15Hz) and high-frequency power (0.15–0.4Hz) of RR interval variability were significantly lower in the UW/UN subjects (P<0.05) than in the NW/WN controls when expressed in absolute units, but not when the low- and high-frequency components were normalized for total power. Baroreflex sensitivity was similarly lower in the UW/UN group (P<0.05). Heart rate variability parameters in the UW/WN group were generally between those of the UW/UN and NW/WN groups, but were not statistically different from either. The mechanisms that contribute to the observed differences between undernourished and normal-weight groups, and the implications of these differences, remain to be elucidated.

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.

Impaired serotonergic regulation of heart rate may underlie reduced baroreflex sensitivity in an animal model of depression

2008 ◽  
Vol 294 (1) ◽  
pp. H474-H480 ◽  
Author(s):  
Cara M. Hildreth ◽  
James R. Padley ◽  
Paul M. Pilowsky ◽  
Ann K. Goodchild
Keyword(s):  
Heart Rate ◽  
Animal Model ◽  
High Frequency ◽  
Neural Control ◽  
Baroreflex Sensitivity ◽  
Cardiac Risk ◽  
Sprague Dawley ◽  
Animal Model Of Depression ◽  
Spontaneous Baroreflex ◽  
Acute Changes

Serotonin (5-HT) is crucial to normal reflex vagal modulation of heart rate (HR). Reduced baroreflex sensitivity [spontaneous baroreflex sensitivity (sBRS)] and HR variability (HRV) reflect impaired neural, particularly vagal, control of HR and are independently associated with depression. In conscious, telemetered Flinders-Sensitive Line (FSL) rats, a well-validated animal model of depression, we tested the hypothesis that cardiovascular regulatory abnormalities are present and associated with deficient serotonergic control of reflex cardiovagal function. In FSL rats and control Flinders-Resistant (FRL) and Sprague-Dawley (SD) rat strains, diurnal measurements of HR, arterial pressure (AP), activity, sBRS, and HRV were made. All strains had normal and similar diurnal variations in HR, AP, and activity. In FRL rats, HR was elevated, contributing to the reduced HRV and sBRS in this strain. In FSL rats, sBRS and high-frequency power HRV were reduced during the night, indicating reduced reflex cardiovagal activity. The ratio of low- to high-frequency bands of HRV was increased in FSL rats, suggesting a relative predominance of cardiac sympathetic and/or reflex activity compared with FRL and SD rats. These data show that conscious FSL rats have cardiovascular regulatory abnormalities similar to depressed humans. Acute changes in HR, AP, temperature, and sBRS in response to 8-hydroxy-2-(di- n-propylamino)tetralin, a 5-HT1A, 5-HT1B, and 5-HT7 receptor agonist, were also determined. In FSL rats, despite inducing an exaggerated hypothermic effect, 8-hydroxy-2-(di- n-propylamino)tetralin did not decrease HR and AP or improve sBRS, suggesting impaired serotonergic neural control of cardiovagal activity. These data suggest that impaired serotonergic control of cardiac reflex function could be one mechanism linking reduced sBRS to increased cardiac risk in depression.

Autonomic cardiovascular and respiratory control during prolonged spaceflights aboard the International Space Station

2007 ◽  
Vol 103 (1) ◽  
pp. 156-161 ◽  
Author(s):  
Roman M. Baevsky ◽  
Victor M. Baranov ◽  
Irina I. Funtova ◽  
André Diedrich ◽  
Andrey V. Pashenko ◽  
...  
Keyword(s):  
Heart Rate ◽  
Transit Time ◽  
High Frequency ◽  
Pulse Wave ◽  
Space Station ◽  
Respiratory Control ◽  
Functional Adaptation ◽  
Pulse Wave Transit Time ◽  
The Individual

Impaired autonomic control represents a cardiovascular risk factor during long-term spaceflight. Little has been reported on blood pressure (BP), heart rate (HR), and heart rate variability (HRV) during and after prolonged spaceflight. We tested the hypothesis that cardiovascular control remains stable during prolonged spaceflight. Electrocardiography, photoplethysmography, and respiratory frequency (RF) were assessed in eight male cosmonauts (age 41–50 yr, body-mass index of 22–28 kg/m2) during long-term missions (flight lengths of 162–196 days). Recordings were made 60 and 30 days before the flight, every 4 wk during flight, and on days 3 and 6 postflight during spontaneous and controlled respiration. Orthostatic testing was performed pre- and postflight. RF and BP decreased during spaceflight ( P < 0.05). Mean HR and HRV in the low- and high-frequency bands did not change during spaceflight. However, the individual responses were different and correlated with preflight values. Pulse-wave transit time decreased during spaceflight ( P < 0.05). HRV reached during controlled respiration (6 breaths/min) decreased in six and increased in one cosmonaut during flight. The most pronounced changes in HR, BP, and HRV occurred after landing. The decreases in BP and RF combined with stable HR and HRV during flight suggest functional adaptation rather than pathological changes. Pulse-wave transit time shortening in our study is surprising and may reflect cardiac output redistribution in space. The decrease in HRV during controlled respiration (6 breaths/min) indicates reduced parasympathetic reserve, which may contribute to postflight disturbances.

scholarly journals Sex differences in baroreflex sensitivity, heart rate variability, and end organ damage in the TGR(mRen2)27 rat

2011 ◽  
Vol 301 (4) ◽  
pp. H1540-H1550 ◽  
Author(s):  
Megan S. Johnson ◽  
Vincent G. DeMarco ◽  
Cheryl M. Heesch ◽  
Adam T. Whaley-Connell ◽  
Rebecca I. Schneider ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Sex Differences ◽  
Baroreflex Sensitivity ◽  
Organ Damage ◽  
Left Ventricular ◽  
Loop Analysis ◽  
Poincaré Plot ◽  
End Organ Damage

The aim of this investigation was to evaluate sex differences in baroreflex and heart rate variability (HRV) dysfunction and indexes of end-organ damage in the TG(mRen2)27 (Ren2) rat, a model of renin overexpression and tissue renin-angiotensin-aldosterone system overactivation. Blood pressure (via telemetric monitoring), blood pressure variability [BPV; SD of systolic blood pressure (SBP)], spontaneous baroreflex sensitivity, HRV [HRV Triangular Index (HRV-TI), standard deviation of the average NN interval (SDNN), low and high frequency power (LF and HF, respectively), and Poincaré plot analysis (SD1, SD2)], and cardiovascular function (pressure-volume loop analysis and proteinuria) were evaluated in male and female 10-wk-old Ren2 and Sprague Dawley rats. The severity of hypertension was greater in Ren2 males (R2-M) than in Ren2 females (R2-F). Increased BPV, suppression of baroreflex gain, decreased HRV, and associated end-organ damage manifested as cardiac dysfunction, myocardial remodeling, elevated proteinuria, and tissue oxidative stress were more pronounced in R2-M compared with R2-F. During the dark cycle, HRV-TI and SDNN were negatively correlated with SBP within R2-M and positively correlated within R2-F; within R2-M, these indexes were also negatively correlated with end-organ damage [left ventricular hypertrophy (LVH)]. Furthermore, within R2-M only, LVH was strongly correlated with indexes of HRV representing predominantly vagal (HF, SD1), but not sympathetic (LF, SD2), variability. These data demonstrated relative protection in females from autonomic dysfunction and end-organ damage associated with elevated blood pressure in the Ren2 model of hypertension.

Muscle metaboreflex attenuates spontaneous heart rate baroreflex sensitivity during dynamic exercise

2007 ◽  
Vol 292 (6) ◽  
pp. H2867-H2873 ◽  
Author(s):  
Javier A. Sala-Mercado ◽  
Masashi Ichinose ◽  
Robert L. Hammond ◽  
Tomoko Ichinose ◽  
Marco Pallante ◽  
...  
Keyword(s):  
Heart Rate ◽  
Exercise Intensity ◽  
Baroreflex Sensitivity ◽  
Pressor Response ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Dynamic Exercise ◽  
Moderate Exercise ◽  
Ventricular Systolic Pressure ◽  
Muscle Metaboreflex

Hypoperfusion of active skeletal muscle elicits a reflex pressor response termed the muscle metaboreflex. Dynamic exercise attenuates spontaneous baroreflex sensitivity (SBRS) in the control of heart rate (HR) during rapid, spontaneous changes in blood pressure (BP). Our objective was to determine whether muscle metaboreflex activation (MRA) further diminishes SBRS. Conscious dogs were chronically instrumented for measurement of HR, cardiac output, mean arterial pressure, and left ventricular systolic pressure (LVSP) at rest and during mild (3.2 km/h) or moderate (6.4 km/h at 10% grade) dynamic exercise before and after MRA (via partial reduction of hindlimb blood flow). SBRS was evaluated as the slopes of the linear relations (LRs) between HR and LVSP during spontaneous sequences of at least three consecutive beats when HR changed inversely vs. pressure (expressed as beats·min−1·mmHg−1). During mild exercise, these LRs shifted upward, with a significant decrease in SBRS (−3.0 ± 0.4 vs. −5.2 ± 0.4, P < 0.05 vs. rest). MRA shifted LRs upward and rightward and decreased SBRS (−2.1 ± 0.1, P < 0.05 vs. mild exercise). Moderate exercise shifted LRs upward and rightward and significantly decreased SBRS (−1.2 ± 0.1, P < 0.05 vs. rest). MRA elicited further upward and rightward shifts of the LRs and reductions in SBRS (−0.9 ± 0.1, P < 0.05 vs. moderate exercise). We conclude that dynamic exercise resets the arterial baroreflex to higher BP and HR as exercise intensity increases. In addition, increases in exercise intensity, as well as MRA, attenuate SBRS.

scholarly journals Study on the Relationship Between Orthostatic Hypotension and Heart Rate Variability, Pulse Wave Velocity Index, and Frailty Index in the Elderly: A Retrospective Observational Study

2020 ◽  
Vol 7 ◽  
Author(s):  
Lun Li ◽  
Huanhuan Li ◽  
Li He ◽  
Hongyan Chen ◽  
Yunqiao Li
Keyword(s):  
Heart Rate ◽  
High Frequency ◽  
Cardiac Cycle ◽  
Pulse Wave ◽  
Frailty Index ◽  
Low Frequency ◽  
The Elderly ◽  
Autonomic Nerve ◽  
Autonomic Nerve Function ◽  
The Relationship

Background: Orthostatic hypotension (OH) is a common disease of the elderly. It is generally believed that the pathogenesis of OH is related to the impairment of autonomic nerve function and the decreased vascular capacity regulation. This study aims to explore the relationship between OH and heart rate variability (HRV) parameters, which reflects autonomic nerve function; ankle-brachial pressure index (ABI), which reflects the degree of vascular stenosis; pulse wave velocity (PWV) index, which reflects vascular stiffness; and frailty index (FI), which reflects the overall health status of the elderly.Methods: From January to September 2018, 24-h HOLTER monitoring, PWV, and ABI were performed in 108 elderly patients with OH and 64 elderly patients who underwent physical examination in our hospital. Analysis software was used to record the subject's standard deviation of the cardiac cycle (SDNN), the standard deviation of the 5-min average cardiac cycle (SDANN), the square root of the average square sum of consecutive n-interval differences (rMSSD), the percentage of the number of adjacent cardiac interval differences &gt;50 ms (pNN50), low frequency (LF), high frequency (HF), very low frequency (VLF), and low frequency/high frequency ratio (LF/HF). Then, FI was evaluated qualitatively and quantitatively in the form of a scale.Results: There was no statistical difference between the two groups on the basis of age, sex, body mass index (BMI), low-density lipoprotein (LDL), resting heart rate, blood pressure, fasting blood glucose, long-term medication, etc. There were significant differences in PWV, SDNN, LF, VLF, and LF/HF between the two groups (P &lt; 0.05). The risk factor of OH in the qualitative (P = 0.04) and quantitative (P = 0.007) index FI was higher in the OH group than in the control group. The risk factors of OH were PWV, SDNN, VLF, LF/HF, and FI, where FI was positively correlated and LF/HF was negatively correlated.Conclusions: The pathogenesis of OH is related to vascular stiffness, imbalance of autonomic nerve regulation, and its comprehensive health status in the elderly. However, arteriosclerosis has not been confirmed as an independent risk factor.Clinical Trial Registration: Retrospectively registered, http://www.chictr.org.cn.

In vivo assessment of LV mass in mice using high-frequency cardiac ultrasound: necropsy validation

1994 ◽  
Vol 266 (4) ◽  
pp. H1672-H1675 ◽  
Author(s):  
W. J. Manning ◽  
J. Y. Wei ◽  
S. E. Katz ◽  
S. E. Litwin ◽  
P. S. Douglas
Keyword(s):  
Heart Rate ◽  
High Frequency ◽  
Accurate Determination ◽  
Anterior Wall ◽  
Left Ventricular ◽  
Mouse Heart ◽  
Inferior Wall ◽  
Lv Mass ◽  
In Vivo Assessment

Left ventricular (LV) mass is an important descriptor of cardiac status that increases with normal aging and may be affected by a variety of disease processes. There are currently limited noninvasive techniques that permit accurate determination of in vivo LV mass in very small animals, such as the mouse, a frequently used model for cardiac research. We sought to evaluate the ability of high-frequency (7.0 or 7.5 MHz), two-dimensional (2-D) guided M-mode echocardiography to estimate in vivo LV mass in the mouse. Fifteen adult mice weighing 22-45 g were studied, including six young adult (2- to 3-mo-old), two adult (12- to 14-mo-old), and seven senescent (18- to 20-mo-old) animals. Resting heart rate varied up to 450 beats/min. Anterior wall, inferior wall, and end-diastolic dimensions were measured, and echocardiographic LV mass (LVMe) was calculated using an uncorrected cube approximation. Autopsy LV mass was determined within 4 h of echocardiographic examination. Autopsy LV mass ranged from 88 to 211 mg. LV chamber dimensions included anterior wall (1.0 +/- 0.2 mm), inferior wall (1.1 +/- 0.3 mm), and end-diastolic dimension (3.7 +/- 0.5 mm). There was a very good correlation between LVMe (x) and autopsy LV mass (y):y = 0.96x - 7, r = 0.94, standard error of the estimate = 18 mg, P < 0.001. This correlation was stronger than that for autopsy LV mass and body weight (r = 0.70) or age (r = 0.74), indexes which until now were the only noninvasive correlates available for this very small animal model. We conclude that, despite the rapid heart rate and small size of the mouse heart, these results demonstrate the potential of high-frequency 2-D guided M-mode transthoracic echocardiography for the in vivo assessment of LV dimensions and mass in the mouse and may prove useful for cardiac research on aging and cardiomyopathies.

Simulation of cardiovascular response to lower body negative pressure from 0 to -40 mmHg

1994 ◽  
Vol 77 (2) ◽  
pp. 630-640 ◽  
Author(s):  
F. M. Melchior ◽  
R. S. Srinivasan ◽  
P. H. Thullier ◽  
J. M. Clere
Keyword(s):  
Heart Rate ◽  
Negative Pressure ◽  
Baroreflex Sensitivity ◽  
Lower Body Negative Pressure ◽  
Cardiovascular Response ◽  
Left Ventricular ◽  
Diastolic Filling ◽  
Lower Body ◽  
Arterial Baroreflex ◽  
Arterial Baroreflex Sensitivity

This paper presents a mathematical model for simulation of the human cardiovascular response to lower body negative pressure (LBNP) up to -40 mmHg both under normal conditions and when arterial baroreflex sensitivity or leg blood capacity (LBC) is altered. Development of the model assumes that the LBNP response could be explained solely on the bases of 1) blood volume redistribution, 2) left ventricular end-diastolic filling, 3) interaction between left ventricle and peripheral circulation, and 4) modulations of peripheral resistances and heart rate by arterial and cardiopulmonary baroreflexes. The model reproduced well experimental data obtained both under normal conditions and during complete autonomic blockade; thus it is validated for simulation of the cardiovascular response from 0 to -40 mmHg LBNP. We tested the ability of the model to simulate the changes in LBNP response due to a reduction in LBC. To assess these changes experimentally, six healthy men were subjected to LBNP of -15, -30, and -38 mmHg with and without wearing elastic compression stockings. Stockings significantly reduced LBC (from 3.9 +/- 0.3 to 1.8 +/- 0.4 ml/100 ml tissue at -38 mmHg LBNP; P < 0.01) and attenuated the change in heart rate (from 23 +/- 4 to 8 +/- 3% at -38 mmHg LBNP; P < 0.05). The model accurately reproduced this result. The model is useful for assessing the influence of LBC or other parameters such as arterial baroreflex sensitivity in diminishing the orthostatic tolerance of humans after spaceflight, bed rest, or endurance training.

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