Heart rate and blood pressure changes during sleep-waking cycles and cataplexy in narcoleptic dogs

1989 ◽  
Vol 256 (1) ◽  
pp. H111-H119 ◽  
Author(s):  
J. M. Siegel ◽  
K. S. Tomaszewski ◽  
H. Fahringer ◽  
G. Cave ◽  
T. Kilduff ◽  
...  

Cataplexy is the abrupt loss of muscle tone experienced by narcoleptics. It is usually precipitated by strong emotions or athletic activity. It has been hypothesized that cardiovascular variables have a role in the triggering of cataplexy. In the present study, we have utilized the narcoleptic canine model to directly investigate changes in heart rate and blood pressure in relation to cataplectic episodes. We found that heart rate increased 18% on average in the 20 s preceding cataplexy onset and then fell during cataplexy. Thus, from a cardiovascular standpoint, cataplexy can be subdivided into two very different periods, the cataplexy onset period with very high and declining heart rate, and the period greater than or equal to 10 s after onset, with greatly reduced heart rate. Heart rate at cataplexy onset was significantly higher than heart rate in rapid-eye-movement (REM) sleep, non-REM sleep, and quiet waking. Blood pressure did not markedly change before the onset of spontaneous cataplexies but decreased significantly during cataplexy. Although blood pressure increases did not precede spontaneous cataplexies, sudden increases in blood pressure, induced pharmacologically or by obstruction of the descending aorta, triggered cataplexy in the most severely affected subjects. A hypothesized role for cataplexy as a homeostatic reflex, triggered by interactions between blood flow, central chemoreceptors, and atonia control mechanisms in the medial medulla, is discussed.

2000 ◽  
Vol 39 (02) ◽  
pp. 200-203
Author(s):  
H. Mizuta ◽  
K. Yana

Abstract:This paper proposes a method for decomposing heart rate fluctuations into background, respiratory and blood pressure oriented fluctuations. A signal cancellation scheme using the adaptive RLS algorithm has been introduced for canceling respiration and blood pressure oriented changes in the heart rate fluctuations. The computer simulation confirmed the validity of the proposed method. Then, heart rate fluctuations, instantaneous lung volume and blood pressure changes are simultaneously recorded from eight normal subjects aged 20-24 years. It was shown that after signal decomposition, the power spectrum of the heart rate showed a consistent monotonic 1/fa type pattern. The proposed method enables a clear interpretation of heart rate spectrum removing uncertain large individual variations due to the respiration and blood pressure change.


Author(s):  
JACK H. WILMORE ◽  
PHILIP R. STANFORTH ◽  
JACQUES GAGNON ◽  
TREVA RICE ◽  
STEPHEN MANDEL ◽  
...  

1967 ◽  
Vol 46 (2) ◽  
pp. 307-315 ◽  
Author(s):  
E. DON STEVENS ◽  
D. J. RANDALL

1. Changes in blood pressure in the dorsal aorta, ventral aorta and subintestinal vein, as well as changes in heart rate and breathing rate during moderate swimming activity in the rainbow trout are reported. 2. Blood pressures both afferent and efferent to the gills increased during swimming and then returned to normal levels within 30 min. after exercise. 3. Venous blood pressure was characterized by periodic increases during swimming. The pressure changes were not in phase with the body movements. 4. Although total venous return to the heart increased during swimming, a decreased blood flow was recorded in the subintestinal vein. 5. Heart rate and breathing rate increased during swimming and then decreased when swimming ceased. 6. Some possible mechanisms regulating heart and breathing rates are discussed.


2010 ◽  
Vol 72 (5) ◽  
pp. 442-449 ◽  
Author(s):  
Jose M. Martinez ◽  
Amir Garakani ◽  
Horacio Kaufmann ◽  
Cindy J. Aaronson ◽  
Jack M. Gorman

2017 ◽  
Vol XXII (130) ◽  
pp. 60-70
Author(s):  
Mariana Werneck Fonseca ◽  
Verônica Batista de Albuquerque ◽  
Gabriel T. N. Martins Ferreira ◽  
Marcelo Augusto de Araújo ◽  
Wagner Luis Ferreira ◽  
...  

This article investigates the electrocardiographic and blood pressure changes caused by different doses of morphine administered epidurally to bitches undergoing elective ovariohysterectomy. Twenty-four healthy bitches weighing 9.8 ± 4.1 kg were assigned to three experimental groups (in each group, n = 8): (i) group M0.1: 0.1 mg/kg morphine; (ii) group M0.15: 0.15 mg/kg morphine; and (iii) group M0.2: 0.2 mg/kg morphine. In all groups, levobupivacaine was added to achieve a total volume of 0.33 mL/kg. During the procedures, the following parameters were controlled: heart rate and rhythm, systolic blood pressure, rectal temperature and blood lactate. The data were analyzed by means of statistical methods of analysis of variance, such as Kruskal-Wallis, Fisher and Tukey tests. Epidural morphine did not cause significant electrocardiographic or blood pressure changes in the tested doses, which makes the use of this drug a viable alternative for epidural anesthesia.


2019 ◽  
Vol 10 (1) ◽  
pp. 209 ◽  
Author(s):  
Nikita S. Pyko ◽  
Svetlana A. Pyko ◽  
Oleg A. Markelov ◽  
Oleg V. Mamontov ◽  
Mikhail I. Bogachev

Six different metrics of mutual coupling of simultaneously registered signals representing blood pressure and pulse interval dynamics have been considered. Stress test responses represented by the reaction of the recorded signals to the external input by tilting the body into the upright position have been studied. Additionally, to the conventional metrics like the joint signal coherence Coher and the sensitivity of the pulse intervals response to the blood pressure changes baroreflex sensitivity (BRS), also alternative indicators like the synchronization coefficient Sync and the time delay stability estimate TDS representing the temporal fractions of the analyzed signal records exhibiting rather synchronous dynamics have been determined. In contrast to BRS, that characterizes the intensity of the pulse intervals response to the blood pressure changes during observed feedback responses, both Sync and TDS likely indicate how often such responses are being activated in the first place. The results indicate that in most cases BRS is typically reciprocal to both Sync and TDS suggesting that low intensity of the feedback responses characterized by low BRS is rather compensated by their more frequent activation indicated by higher Sync and TDS. The proposed additional indicators could be complementary for the differential diagnostics of blood pressure regulation efficacy and also lead to a deeper insight into the involved concomitant factors this way also aiming at the improvement of the mathematical models representing the underlying feedback control mechanisms.


1998 ◽  
Vol 274 (4) ◽  
pp. R1136-R1141 ◽  
Author(s):  
Richard L. Verrier ◽  
T. Rern Lau ◽  
Umesha Wallooppillai ◽  
James Quattrochi ◽  
Bruce D. Nearing ◽  
...  

Rapid eye movement (REM) sleep results in profound state-dependent alterations in heart rate. The present study describes a novel phenomenon of a primary deceleration in heart rate that is not preceded or followed by increases in heart rate or arterial blood pressure and occurs primarily during tonic REM sleep. The goals were to characterize the primary decelerations and to provide insights on the underlying central and peripheral autonomic mechanisms. Cats were chronically implanted with electrodes to record electroencephalogram, pontogeniculooccipital wave activity in lateral geniculate nucleus, hippocampal theta rhythm, electromyogram, electrooculogram, respiration (diaphragm), and electrocardiogram. Arterial blood pressure was monitored from a carotid artery catheter. R-R interval fluctuations were continuously tracked using customized software. The muscarinic blocking agent glycopyrrolate (0.1 mg/kg iv) and the β-adrenergic blocking agent atenolol (0.3 mg/kg iv) were administered in alternating sequence with a 90- to 120-min interval. Glycopyrrolate immediately eliminated the decelerations during REM sleep. Atenolol alone had no effect on their frequency. These findings suggest that a change in the centrally induced pattern of autonomic activity to the heart is responsible for the primary decelerations, namely, a bursting of cardiac vagal efferent fiber activity.


1982 ◽  
Vol 56 (5) ◽  
pp. 392-394 ◽  
Author(s):  
SERGIO M. GREGORETTI ◽  
YUNG JAI SOHN ◽  
ROBERTO L. SIA

2019 ◽  
Vol 127 (5) ◽  
pp. 1386-1402 ◽  
Author(s):  
E. Benjamin Randall ◽  
Anna Billeschou ◽  
Louise S. Brinth ◽  
Jesper Mehlsen ◽  
Mette S. Olufsen

The Valsalva maneuver (VM) is a diagnostic protocol examining sympathetic and parasympathetic activity in patients with autonomic dysfunction (AD) impacting cardiovascular control. Because direct measurement of these signals is costly and invasive, AD is typically assessed indirectly by analyzing heart rate and blood pressure response patterns. This study introduces a mathematical model that can predict sympathetic and parasympathetic dynamics. Our model-based analysis includes two control mechanisms: respiratory sinus arrhythmia (RSA) and the baroreceptor reflex (baroreflex). The RSA submodel integrates an electrocardiogram-derived respiratory signal with intrathoracic pressure, and the baroreflex submodel differentiates aortic and carotid baroreceptor regions. Patient-specific afferent and efferent signals are determined for 34 control subjects and 5 AD patients, estimating parameters fitting the model output to heart rate data. Results show that inclusion of RSA and distinguishing aortic/carotid regions are necessary to model the heart rate response to the VM. Comparing control subjects to patients shows that RSA and baroreflex responses are significantly diminished. This study compares estimated parameter values from the model-based predictions to indices used in clinical practice. Three indices are computed to determine adrenergic function from the slope of the systolic blood pressure in phase II [ α (a new index)], the baroreceptor sensitivity ( β), and the Valsalva ratio ( γ). Results show that these indices can distinguish between normal and abnormal states, but model-based analysis is needed to differentiate pathological signals. In summary, the model simulates various VM responses and, by combining indices and model predictions, we study the pathologies for 5 AD patients. NEW & NOTEWORTHY We introduce a patient-specific model analyzing heart rate and blood pressure during a Valsalva maneuver (VM). The model predicts autonomic function incorporating the baroreflex and respiratory sinus arrhythmia (RSA) control mechanisms. We introduce a novel index ( α) characterizing sympathetic activity, which can distinguish control and abnormal patients. However, we assert that modeling and parameter estimation are necessary to explain pathologies. Finally, we show that aortic baroreceptors contribute significantly to the VM and RSA affects early VM.


1982 ◽  
Vol 62 (6) ◽  
pp. 581-588 ◽  
Author(s):  
Massimo Volpe ◽  
Bruno Trimarcoy ◽  
Bruno Ricciardelli ◽  
Carlo Vigorito ◽  
Nicola De Luca ◽  
...  

1. The effects of intravenous administration of neostigmine and propranolol, individually or in combination, on baroreflex responsiveness have been evaluated in 18 borderline hypertensive subjects and in 14 age-matched control subjects. 2. Baroreceptor sensitivity was tested by evaluating both heart rate response to phenylephrine-induced increase in arterial pressure, and heart rate and blood pressure changes induced by increasing neck-tissue pressure by means of a neck-chamber. 3. In borderline hypertensive subjects a reduced baroreflex responsiveness was demonstrated with both stimuli as compared with normal subjects. Neostigmine administration improved consistently both reflex responses. Similarly, after propranolol treatment, borderline hypertensive subjects showed a significant enhancement of the baroreflex sensitivity. Finally, the combined administration of neostigmine and propranolol restored the baroreflex responses. In fact, both the mean slopes of the regression lines between blood pressure and R-R interval after phenylephrine and the increase in mean arterial pressure and heart rate induced by the reduction in carotid transmural pressure in borderline hypertensive subjects were similar to those observed in normals. 4. These findings indicate that in borderline hypertensive subjects the impairment of baroreflex responsiveness is mainly due to abnormalities of autonomic regulation.


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