Effects of carotid baroreceptor stimulation on aortic remodeling in obese rats

Hemodynamic alterations during balloon carotid angioplasty (BCA) and stenting have been ascribed to the consequences of direct carotid baroreceptor stimulation during balloon inflation. BCA with stenting in patients with carotid atheromatous stenoses offers a unique opportunity for elucidating the cardiovascular autonomic response to direct transient intravascular stimulation of the baroreceptors. We analysed the consequences of BCA on the autonomic control of heart rate and on breathing components in nine patients with atheromatous stenoses involving the bifurcation and the internal carotid. A timefrequency domain method, the smoothed pseudo-WignerVille transform (SPWVT), was used to evaluate the spectral parameters (i.e., the instantaneous amplitude and centre frequency (ICF) of the cardiovascular and respiratory oscillations). Those parameters and their dynamics (8 and 24 h later) were evaluated during and after the procedure. BCA stimulates baroreceptors in all patients, which markedly reduces heart rate and blood pressure. Vagal baroreflex activation altered the respiratory sinus arrhythmia in terms of amplitude and frequency (ICF HF RR shifted from 0.27 ± 0.03 to 0.23 ± 0.04 Hz pre-BCA vs. BCA, respectively; p < 0.01). Both the high- and low-frequency amplitudes of heart rate oscillations were altered during carotid baroreceptor stimulation, strongly supporting a contribution of the baroreflex to the generation of both oscillations of heart rate. Carotid baroreceptors stimulation increased the inspiratory time (Ti) (1.5 ± 0.5 to 2.3 ± 0.6 s pre-BCA vs. BCA, respectively; p < 0.01). In awake patients, BCA with stenting of atheromatous stenosis involving the bifurcation and internal carotid causes marked changes in the cardiac autonomic and respiratory control systems.Key words: carotid angioplasty, heart rate variability, autonomic nervous system, respiration, spectral analysis.

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Carotid Baroreceptor Stimulation: A Promising Approach for the Management of Resistant Hypertension and Heart Failure

Current Vascular Pharmacology ◽

10.2174/15701611113119990138 ◽

2014 ◽

Vol 12 (1) ◽

pp. 30-37 ◽

Cited By ~ 8

Author(s):

Doumas M. ◽

Faselis C. ◽

Kokkinos P. ◽

Anyfanti P. ◽

Tsioufis C. ◽

...

Keyword(s):

Heart Failure ◽

Resistant Hypertension ◽

Carotid Baroreceptor ◽

Baroreceptor Stimulation ◽

Carotid Baroreceptor Stimulation

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Central volume expansion is pivotal for sustained decrease in heart rate during seated to supine posture change

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.2001.281.3.h1274 ◽

2001 ◽

Vol 281 (3) ◽

pp. H1274-H1279 ◽

Cited By ~ 11

Author(s):

Bettina Pump ◽

Tsutomu Kamo ◽

Anders Gabrielsen ◽

Peter Bie ◽

Niels Juel Christensen ◽

...

Keyword(s):

Heart Rate ◽

Pulse Pressure ◽

Volume Expansion ◽

Arterial Pulse ◽

Carotid Baroreceptor ◽

Posture Change ◽

Arterial Pulse Pressure ◽

Baroreceptor Stimulation ◽

Central Volume ◽

Carotid Baroreceptor Stimulation

During prolonged, static carotid baroreceptor stimulation by neck suction (NS) in seated humans, heart rate (HR) decreases acutely and thereafter gradually increases. This increase has been explained by carotid baroreceptor adaptation and/or buffering by aortic reflexes. During a posture change from seated to supine (Sup) with similar carotid stimulation, however, the decrease in HR is sustained. To investigate whether this discrepancy is caused by changes in central blood volume, we compared ( n = 10 subjects) the effects of 10 min of seated NS (adjusted to simulate carotid stimulation of a posture change), a posture change from seated to Sup, and the same posture change with left atrial (LA) diameter maintained unchanged by lower body negative pressure (Sup + LBNP). During Sup, the prompt decreases in HR and mean arterial pressure (MAP) were sustained. HR decreased similarly within 30 s of NS (65 ± 2 to 59 ± 2 beats/min) and Sup + LBNP (65 ± 2 to 58 ± 2 beats/min) and thereafter gradually increased to values of seated. MAP decreased similarly within 5 min during Sup + LBNP and NS (by 7 ± 1 to 9 ± 1 mmHg) and thereafter tended to increase toward values of seated subjects. Arterial pulse pressure was increased the most by Sup, less so by Sup + LBNP, and was unchanged by NS. LA diameter was only increased by Sup. In conclusion, static carotid baroreceptor stimulation per se causes the acute (<30 s) decrease in HR during a posture change from seated to Sup, whereas the central volume expansion (increased LA diameter and/or arterial pulse pressure) is pivotal to sustain this decrease. Thus the effects of central volume expansion override adaptation of the carotid baroreceptors and/or buffering of aortic reflexes.

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Carotid Baroreceptor Stimulation for the Treatment of Resistant Hypertension

International Journal of Hypertension ◽

10.4061/2011/964394 ◽

2011 ◽

Vol 2011 ◽

pp. 1-5 ◽

Cited By ~ 13

Author(s):

Vasilios Papademetriou ◽

Michael Doumas ◽

Charles Faselis ◽

Constantinos Tsioufis ◽

Stella Douma ◽

...

Keyword(s):

Blood Pressure ◽

Resistant Hypertension ◽

Blood Pressure Reduction ◽

Current Data ◽

Pressure Reduction ◽

Beneficial Effects ◽

Carotid Baroreceptor ◽

Complex Anatomy ◽

Baroreceptor Stimulation ◽

Carotid Baroreceptor Stimulation

Interventional activation of the carotid baroreflex has been an appealing idea for the management of resistant hypertension for several decades, yet its clinical application remained elusive and a goal for the future. It is only recently that the profound understanding of the complex anatomy and pathophysiology of the circuit, combined with the accumulation of relevant experimental and clinical data both in animals and in humans, has allowed the development of a more effective and well-promising approach. Indeed, current data support a sustained over a transient reduction of blood pressure through the resetting of baroreceptors, and technical deficits have been minimized with a subsequent recession of adverse events. In addition, clinical outcomes from the application of a new implantable device (Rheos) that induces carotid baroreceptor stimulation point towards a safe and effective blood pressure reduction, but longer experience is needed before its integration in the everyday clinical practice. While accumulating evidence indicates that carotid baroreceptor stimulation exerts its benefits beyond blood pressure reduction, further research is necessary to assess the spectrum of beneficial effects and evaluate potential hazards, before the extraction of secure conclusions.

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