Enhanced parasympathetic tone shortens atrial refractoriness in man

Background Cluster headache (CH) attacks are accompanied by cranial autonomic symptoms indicative of parasympathetic hyperactivity and sympathetic dysfunction ipsilateral to the pain. We aimed to assess cranial autonomic function in CH patients during the remission phase of cluster headache. Materials and methods During a remission phase, 38 episodic CH patients underwent the following: dynamic pupillometry, measurement of the superficial temporal artery diameter by ultrasound, and measurement of the retinal vessel diameters from digital retinal photographs. Pupillometry was also performed on 30 age- and sex-matched healthy controls. Results Thirty patients were included (27 men, three women, mean age 50.2 years ± 12.6). Seven patients reported occasional side shift of their headache, but with a clear predominating side. Significantly reduced average pupillary constriction velocity and retinal venular diameter on the CH pain side were found. There was no asymmetry of the superficial temporal artery diameters. Compared to healthy controls, cluster patients displayed bilaterally reduced pupillary average and maximum constriction velocities, reduced constriction in percentage and increased latency of the light reflex. Conclusions The present findings indicate a bilaterally reduced cranial parasympathetic tone in CH patients in remission phase, with significant lateralization to the CH pain side. This implies a central origin, and a central pathophysiological model of CH is discussed.

Download Full-text

Abstract P132: Increased Cardiovascular Parasympathetic Tone in African Americans With CD36 Partial Deficiency

Hypertension ◽

10.1161/hyp.70.suppl_1.p132 ◽

2017 ◽

Vol 70 (suppl_1) ◽

Author(s):

Shahram Ejtemaei Mehr

Keyword(s):

Heart Rate ◽

Fatty Acid ◽

African Americans ◽

Heart Function ◽

Taste Perception ◽

Acid Uptake ◽

High Fat ◽

Cd36 Deficiency ◽

Parasympathetic Tone ◽

Fat Meal

Cardiovascular disease is the leading cause of death among African Americans (AA). Reduced parasympathetic tone as measured by high frequency heart rate variability (HF RRI ) predicts cardiovascular mortality. HF RRI is reduced after a high fat meal through caveolar sequestration of muscarinic M2 receptors. The fatty acid translocase CD36 is a protein abundant in the myocardium and important for heart function and lipid metabolism. CD36 plasma membrane localization and function in fatty acid uptake is modulated by its interaction with caveolin. One in four AAs are G-allele carriers for CD36 SNP rs3211938 resulting in ~50% decreased CD36 expression. CD36 deficiency also reduces fat taste perception, which might lead to higher fat intake to reach taste saturation. We tested the hypothesis that obese AAs with partial CD36 deficiency have altered parasympathetic tone during fasting and after a high-fat meal. We recruited 13 G-allele carriers and 39 non-carriers. Subjects were matched by age (P=0.820), BMI (P=0.751), and blood pressure (P=0.701). There was a trend towards reduction in heart rate in carriers (P=0.07). Baseline HF RRI was elevated in G carriers (557.1 [251 to 942] vs. 224 [95 to 655] ms 2 , P=0.046). Eleven subjects received a high-fat meal (700 Cal/m 2 BSA, 80% fat). HF RRI was measured at baseline and 30, 60, 120, 240 minutes after meal. Non-carriers (n=4) showed a time-dependent decline in the percent change in HF RRI (-23, -32, -70, -84, respectively). In G-allele carriers (N=6), the decline in HF RRI (21, -11, -61, -70 min) was attenuated. Conclusion: AAs with partial CD36 deficiency have enhanced fasting parasympathetic tone and a blunted response to a high fat meal.

Download Full-text

Effects of Verapamil and Ibutilide on Atrial Fibrillation and Postfibrillation Atrial Refractoriness

Journal of Cardiovascular Electrophysiology ◽

10.1046/j.1540-8167.2002.00151.x ◽

2002 ◽

Vol 13 (2) ◽

pp. 151-157 ◽

Cited By ~ 17

Author(s):

CHRISTIAN STICHERLING ◽

WILLIAM HSU ◽

HIROSHI TADA ◽

ANTON C. BARES ◽

HAKAN ORAL ◽

...

Keyword(s):

Atrial Fibrillation ◽

Atrial Refractoriness

Download Full-text

P314Modifications of atrial refractoriness produced in an experimental rabbit model of diet-induced metabolic syndrome

Cardiovascular Research ◽

10.1093/cvr/cvy060.229 ◽

2018 ◽

Vol 114 (suppl_1) ◽

pp. S80-S80

Author(s):

O J Arias-Mutis ◽

C J Calvo ◽

A Bizy ◽

L Such-Miquel ◽

C Soler ◽

...

Keyword(s):

Metabolic Syndrome ◽

Rabbit Model ◽

Atrial Refractoriness

Download Full-text

Performance of the Parasympathetic Tone activity (PTA) index to predict mean arterial pressure variations in anaesthetized horses with different health conditions

10.21203/rs.3.rs-27993/v1 ◽

2020 ◽

Author(s):

Christelle Mansour ◽

Rita Mocci ◽

Bruna Santangelo ◽

Rana Chaaya ◽

Bernard Allaouchiche ◽

...

Keyword(s):

Mean Arterial Pressure ◽

Arterial Pressure ◽

Significant Variation ◽

Threshold Value ◽

Health Condition ◽

Health Conditions ◽

Dynamic Variations ◽

Autonomic Dysfunctions ◽

Elective Group ◽

Parasympathetic Tone

Abstract Background The parasympathetic tone activity (PTA) is an index based on heart rate variability recently developed in animals to assess their relative parasympathetic tone and their analgesia nociception balance. The present study aimed to evaluate the variation of PTA in anaesthetized horses according to haemodynamic status and health conditions and to determine the performance of dynamic variations of PTA (∆PTA) to predict mean arterial pressure (MAP) variations. Results Thirty-nine client-horses admitted to the Veterinary Campus of Lyon were anaesthetized for elective or emergency surgery and divided into “Colic” and “Elective” groups. During anaesthesia, dobutamine was administered as treatment of hypotension (MAP < 60 mmHg). No significant variation of PTA and MAP were detected at steady-state and following cutaneous incision. PTA increased before each hypotension (+ 15% in Elective and + 11.4% in Colic group), conversely, the administration of dobutamine was accompanied by a significant decrease in PTA (-12.7% in Elective and − 9% in Colic group). Horses of the Colic group had lower PTA values than those in Elective group, whereas MAP didn’t differ between groups. Globally, to predict a 10% increase in MAP, ΔPTA performance was associated with: AUC ROC [95% CI] = 0.77 [0.70 to 0.83] (p < 0.0001), with a sensitivity of 88.2% and a specificity of 57.7% for a threshold value of − 1%. Besides, to predict a 10% decrease in MAP, ΔPTA performance was associated with: AUC ROC [95% CI] = 0.80 [0.73 to 0.85] (p < 0.0001), with a sensitivity of 62.5% and a specificity of 94.6% for a threshold value of 25%. Conclusions The PTA index in anaesthetized horses appears to be influenced by the haemodynamic status and the health condition. The shift toward lower PTA values in colic horses may potentially reflect a sympathetic tone predominance. Of clinical significance, a PTA increase of > 25% in 1 min showed fair performance to predict a MAP decrease of > 10% within 5 min but a decrease in PTA was poorly specific to predict an increase in MAP. Even though these results require further evaluation, this index may thus help to predict potential autonomic dysfunctions in sick animals.

Download Full-text

Transient Increase of Parasympathetic Tone in Patients with Cervical Spinal Cord Trauma

Anaesthesia and Intensive Care ◽

10.1177/0310057x9302100217 ◽

1993 ◽

Vol 21 (2) ◽

pp. 218-221 ◽

Cited By ~ 7

Author(s):

M. Kawamoto ◽

S. Sakimura ◽

M. Takasaki

Keyword(s):

Spinal Cord ◽

Cervical Spinal Cord ◽

Transient Increase ◽

Spinal Cord Trauma ◽

Parasympathetic Tone

Download Full-text

Effect of anomalous pathway location on rate of canine experimental A-V reentrant tachycardia

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1977.233.1.h44 ◽

1977 ◽

Vol 233 (1) ◽

pp. H44-H49

Author(s):

S. Teague ◽

P. Denes ◽

F. Amat-y-Leon ◽

K. M. Rosen

Keyword(s):

Cycle Length ◽

Electronic Circuit ◽

The Other ◽

Conduction Time ◽

Reentrant Tachycardia ◽

Intraventricular Conduction ◽

Atrial Refractoriness ◽

The Relationship ◽

Atrial Stimulation ◽

Anterior Posterior

The effect of anomalous pathway (AP) location and conduction time on the cycle length (CL) and sustainability of paroxysmal A-V reentrant tachycardia was studied in 15 dogs, using an anomalous pathway simulator (APS). The APS was a programmable digital electronic circuit with ability for unidirectional conduction, ventricular sensing, adjustable delay, and atrial stimulation. Contiguous pairs of ventricular sensing electrodes were placed along the A-V ring in each dog at the following sites: anterior, posterior, and lateral right (AR, PR, and LR) and anterior, posterior, and lateral left (AL, PL, and LL) and septal (S). There were significant differences in the CL of tachycardias among the tested sites (P less than 0.01). The CL of tachycardias from the LL site was significantly longer and from the PR site significantly shorter than that from the other sites (P less than 0.05). These differences in CL of tachycardias in relation to the AP location were explicable in terms of corresponding variation in conduction times of the various components of the tachycardia circuit (e.g., intra-atrial, A-V nodal, intraventricular conduction times). The differences in magnitude of the CL of tachycardias, although significant, were small. It was also found that all sites allowed maintenance of tachycardias up to an AP conduction time of 10 ms. In 27% of experiments, atrial refractoriness prevented sustained tachycardias at pathway delays of 1 ms. The relationship between AP conduction time and CL of tachycardias was exponential.

Download Full-text