scholarly journals Exaggerated muscle mechanoreflex control of reflex renal vasoconstriction in heart failure

2001 ◽  
Vol 90 (5) ◽  
pp. 1714-1719 ◽  
Author(s):  
Holly R. Middlekauff ◽  
Egbert U. Nitzsche ◽  
Carl K. Hoh ◽  
Michele A. Hamilton ◽  
Gregg C. Fonarow ◽  
...  
Keyword(s):  
Heart Failure ◽  
Statistical Significance ◽  
Central Command ◽  
Renal Vasoconstriction ◽  
Involuntary Muscle ◽  
Positron Emission ◽  
Intact Muscle ◽  
Muscle Mechanoreceptor ◽  
Muscle Mechanoreflex ◽  
Renal Cortical Blood Flow

In heart failure (HF) patients, reflex renal vasoconstriction during exercise is exaggerated. We hypothesized that muscle mechanoreceptor control of renal vasoconstriction is exaggerated in HF. Nineteen HF patients and nineteen controls were enrolled in two exercise protocols: 1) low-level rhythmic handgrip (mechanoreceptors and central command) and 2) involuntary biceps contractions (mechanoreceptors). Renal cortical blood flow was measured by positron emission tomography, and renal cortical vascular resistance (RCVR) was calculated. During rhythmic handgrip, peak RCVR was greater in HF patients compared with controls (37 ± 1 vs. 27 ± 1 units; P < 0.01). Change in (Δ) RCVR tended to be greater as well but did not reach statistical significance (10 ± 1 vs. 7 ± 0.9 units; P = 0.13). RCVR was returned to baseline at 2–3 min postexercise in controls but remained significantly elevated in HF patients. During involuntary muscle contractions, peak RCVR was greater in HF patients compared with controls (36 ± 0.7 vs. 24 ± 0.5 units; P < 0.0001). The Δ RCVR was also significantly greater in HF patients compared with controls (6 ± 1 vs. 4 ± 0.6 units; P = 0.05). The data suggest that reflex renal vasoconstriction is exaggerated in both magnitude and duration during dynamic exercise in HF patients. Given that the exaggerated response was elicited in both the presence and absence of central command, it is clear that intact muscle mechanoreceptor sensitivity contributes to this augmented reflex renal vasoconstriction.

Renal blood flow in heart failure patients during exercise

2004 ◽  
Vol 287 (6) ◽  
pp. H2834-H2839 ◽  
Author(s):  
Afsana Momen ◽  
Douglas Bower ◽  
John Boehmer ◽  
Allen R. Kunselman ◽  
Urs A. Leuenberger ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Maximum Voluntary Contraction ◽  
Exercise Intolerance ◽  
Compensatory Mechanism ◽  
Central Command ◽  
Renal Vasoconstriction ◽  
Muscle Mechanoreflex ◽  
Early Phases

During exercise, reflex renal vasoconstriction maintains blood pressure and helps in redistributing blood flow to the contracting muscle. Exercise intolerance in heart failure (HF) is thought to involve diminished perfusion in active muscle. We studied the temporal relationship between static handgrip (HG) and renal blood flow velocity (RBV; duplex ultrasound) in 10 HF and in 9 matched controls during 3 muscle contraction paradigms. Fatiguing HG ( protocol 1) at 40% of maximum voluntary contraction led to a greater reduction in RBV in HF compared with controls (group main effect: P < 0.05). The reduction in RBV early in HG tended to be more prominent during the early phases of protocol 1. Similar RBV was observed in the two groups during post-HG circulatory arrest (isolating muscle metaboreflex). Short bouts (15 s) of HG at graded intensities ( protocol 2; engages muscle mechanoreflex and/or central command) led to greater reductions in RBV in HF than controls ( P < 0.03). Protocol 3, voluntary and involuntary biceps contraction (eliminates central command), led to similar increases in renal vasoconstriction in HF ( n = 4). Greater reductions in RBV were found in HF than in controls during the early phases of exercise. This effect was not likely due to a metaboreflex or central command. Thus our data suggest that muscle mechanoreflex activity is enhanced in HF and serves to vigorously vasoconstrict the kidney. We believe this compensatory mechanism helps preserve blood flow to exercising muscle in HF.

A perspective on the muscle reflex: implications for congestive heart failure

2005 ◽  
Vol 99 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Lawrence I. Sinoway ◽  
Jianhua Li
Keyword(s):  
Heart Failure ◽  
Muscle Afferents ◽  
Receptor Subtype ◽  
Renal Vasoconstriction ◽  
Exercise Pressor Reflex ◽  
Acid Sensing Ion Channels ◽  
Health And Disease ◽  
Reflex Activation ◽  
Muscle Mechanoreflex ◽  
Muscle Reflex

In this review we examine the exercise pressor reflex in health and disease. The role of metabolic and mechanical stimulation of thin fiber muscle afferents is discussed. The role ATP and lactic acid play in stimulating and sensitizing these afferents is examined. The role played by purinergic receptors subdivision 2, subtype X, vanilloid receptor subtype 1, and acid-sensing ion channels in mediating the effects of ATP and H+ are discussed. Muscle reflex activation in heart failure is then examined. Data supporting the concept that the metaboreflex is attenuated and that the mechanoreflex is accentuated are presented. The role the muscle mechanoreflex plays in evoking renal vasoconstriction is also described.

scholarly journals AB0798 EFFECT OF ANTIRHEUMATIC THERAPY ADMINISTERED IN ACCORDANCE WITH “TREAT TO TARGET” PRINCIPLES ON DIASTOLIC DYSFUNCTION OF THE LEFT VENTRICLES IN PATIENTS WITH ACTIVE EARLY PSORIATIC ARTHRITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1699.2-1699
Author(s):  
E. Markelova
Keyword(s):  
Heart Failure ◽  
Diastolic Dysfunction ◽  
Inflammatory Diseases ◽  
Statistical Significance ◽  
Certolizumab Pegol ◽  
Cardiovascular Death ◽  
Treat To Target ◽  
Antirheumatic Therapy ◽  
Time Curve ◽  
Low Prevalence

Background:Рsoriatic arthritis (PsA) are chronic inflammatory diseases, with massive increase of cardiovascular events (CVE) and cardiovascular death. Diastolic dysfunction of the left ventricles (LVDD) is a risk factor for the development of the heart failure.Objectives:to study the effect of antirheumatic therapy administered in accordance with “Treat to target” principles on LVDD in early PsA (EPsA) patients (pts).Methods:48 (F.-23) DMARD-naive PsA pts, according to the CASPAR criteria, age 36[27; 45] years (yrs.), PsA duration – 6[4; 8] months. All pts were assessed for transthoracic echocardiography. Diastolic function was determined by early and atrial peak filling rates derived from differential volume-time-curve analysis. Methotrexate therapy was started in all pts with an escalation of the dose up to 25 mg/week subcutaneously. In case of no remission 3 months later, MT was added with biologic therapy: Adalimumab, Certolizumab pegol, Ustekinumab. Antihypertensive therapy received all pts with arterial hypertension (AH). All p less then 0.05 considered to statistical significance.Results:At baseline LVDD was identified in 5(10.4%). The LVDD pts were older, in more cases they had AH, abdominal obesity (p<0.05). Significant negative correlations were found between LVDD and body mass index (BMI) (r=-0.41), age (r=-0.71), total cholesterol (r=-0.44), triglycerides (r=-0.48), low density lipoproteins (r=-0.44), systolic (r=-0.59) and diastolic blood pressure (r=-0.4), for all p<0,01. By 18 months of therapy significantly decreased DAS from 4.06[3.48; 4.91] to 0,97[0,65;1,48]; C-RP from 19.4 [8.8;37.5] to 2.2 [0.9; 4.6]mg/l, for all p<0,001. DAS remission was achieved in 69% of pts. We didn’t find significant differences between baseline and after treatment the frequency of LVDD – 5(10,4%) to 4(8.3%).Conclusion:in pts with EPsA frequently (10.4%) were detected LVDD, which are associated with a АН, age, higher BMI. Low prevalence LVDD in patients with EPsA is possibly caused by short duration of disease and early start of antirheumatic therapy. This has implications for development of preventive strategies for heart failure in EPsA patients.Disclosure of Interests:None declared

Prognostic value of the cardiorespiratory optimal point during submaximal exercise testing

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J.P Dias Ferreira Reis ◽  
A Goncalves ◽  
P Bras ◽  
V Ferreira ◽  
J Viegas ◽  
...  
Keyword(s):  
Heart Failure ◽  
Primary Endpoint ◽  
Statistical Significance ◽  
Peak Level ◽  
Submaximal Exercise ◽  
Peak Oxygen Consumption ◽  
Optimal Point ◽  
Reduced Ejection Fraction ◽  
Tertiary Center ◽  
The Mean

Abstract Background Peak oxygen consumption (pVO2) is a key parameter in assessing the prognosis of heart failure with reduced ejection fraction (HFrEF) patients (pts). However, it is a less reliable parameter when the cardiopulmonary exercise test (CPET) is not maximal. It is crucial to identify the submaximal exercise variables with the best prognostic power (PP), in order to improve the management of pts that cannot attain a maximal CPET. Purpose The aim of this study was to evaluate and compare the PP of several exercise parameters in submaximal CPET for risk stratification in pts with HFrEF. Methods Prospective evaluation of adult pts with HFrEF submitted to CPET in a tertiary center. A submaximal CPET was defined by a respiratory exchange ratio (RER) ≤1.10. Pts were followed up for at least 1 year for the primary endpoint of cardiac death and urgent heart transplantation/ ventricular assist device implantation. Several CPET parameters were analyzed as potential predictors of the combined endpoint and their PP (area under the curve - AUC) was compared to that of pVO2, using the Hanley and McNeil test. Results CPET was performed in 487 HF pts, of which 317 (66%) performed a submaximal CPET. Pts averaged 57±12 years of age, 77% were male, 45.7% had ischemic cardiomyopathy, with a mean LVEF of 30.4±7.6%, a mean heart failure survival score of 8.6±1.1. The mean pVO2 was 17.1±5.5 ml/kg/min and the mean RER 1.01±0.08. During a mean follow-up (FU) time of 11±1 months, 18 pts (6%) met the primary endpoint. Cardiorespiratory optimal point (OP - VE/VO2) had the highest AUC value (0.915, p=0.001), followed by the partial pressure of end-tidal CO2 at the anaerobic threshold - PETCO2L (0.814, p&lt;0.001). pVO2 presented an AUC of 0.730 (p=0.001). OP≥31 and PETCO2L ≤37mmHg had a sensitivity of 100 and 76.9% and a specificity of 71.1 and 67%, respectively, for the primary outcome. OP presented a significantly higher PP than pVO2 (p=0.048), whether PETCO2L didn't achieve any statistical significance (p=0.164). Pts with anOP≥31 presented a significantly lower survival free of HT during FU (log rank p=0.002). Conclusion OP had the highest PP for HF events of all parameters analyzed for a submaximal CPET. This parameter can help stratify the HF pts physiologically unable to reach a peak level of exercise. Funding Acknowledgement Type of funding source: None

scholarly journals Acute acetate administration increases endogenous opioid levels in the human brain: A [11C]carfentanil molecular imaging study

2021 ◽  
pp. 026988112096591
Author(s):  
Abhishekh H Ashok ◽  
Jim Myers ◽  
Gary Frost ◽  
Samuel Turton ◽  
Roger N Gunn ◽  
...  
Keyword(s):  
Human Brain ◽  
Sodium Acetate ◽  
Statistical Significance ◽  
Imaging Study ◽  
Pet Scan ◽  
Endogenous Opioid ◽  
Reference Tissue ◽  
Healthy Human ◽  
Fourfold Increase ◽  
Positron Emission

Introduction: A recent study has shown that acetate administration leads to a fourfold increase in the transcription of proopiomelanocortin (POMC) mRNA in the hypothalamus. POMC is cleaved to peptides, including β-endorphin, an endogenous opioid (EO) agonist that binds preferentially to the µ-opioid receptor (MOR). We hypothesised that an acetate challenge would increase the levels of EO in the human brain. We have previously demonstrated that increased EO release in the human brain can be detected using positron emission tomography (PET) with the selective MOR radioligand [11C]carfentanil. We used this approach to evaluate the effects of an acute acetate challenge on EO levels in the brain of healthy human volunteers. Methods: Seven volunteers each completed a baseline [11C]carfentanil PET scan followed by an administration of sodium acetate before a second [11C]carfentanil PET scan. Dynamic PET data were acquired over 90 minutes, and corrected for attenuation, scatter and subject motion. Regional [11C] carfentanil BPND values were then calculated using the simplified reference tissue model (with the occipital grey matter as the reference region). Change in regional EO concentration was evaluated as the change in [11C]carfentanil BPND following acetate administration. Results: Following sodium acetate administration, 2.5–6.5% reductions in [11C]carfentanil regional BPND were seen, with statistical significance reached in the cerebellum, temporal lobe, orbitofrontal cortex, striatum and thalamus. Conclusions: We have demonstrated that an acute acetate challenge has the potential to increase EO release in the human brain, providing a plausible mechanism of the central effects of acetate on appetite in humans.

L'aumento del segnale di colina coincide con la trasformazione maligna dei gliomi cerebrali: Studio longitidinale con imaging di spettroscopia protonica in risonanza magnetica

1997 ◽  
Vol 10 (2_suppl) ◽  
pp. 18-19
Author(s):  
G. Tedeschi ◽  
N. Lundbom ◽  
R. Raman ◽  
S. Bonavita ◽  
J.H. Duyn ◽  
...  
Keyword(s):  
Proton Magnetic Resonance ◽  
Statistical Significance ◽  
Risonanza Magnetica ◽  
Emission Tomography ◽  
Magnetic Resonance Spectroscopic Imaging ◽  
Malignant Degeneration ◽  
High Grade ◽  
Positron Emission ◽  
Cerebral Gliomas ◽  
High Degree

We tested the hypothesis that proton magnetic resonance spectroscopic imaging (1H-MRSI) can be used as a supportive diagnostic tool to differentiate clinically stable brain tumors from those progressing as a result of either low-to-high grade malignant transformation or of post-therapeutic recurrence. Twenty-seven patients with histologically verified cerebral gliomas were studied repeatedly with 1H-MRSI over a period of 3.5 years. At the time of each 1H-MRSI study, clinical examination, MRI, positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG), and biopsy findings (when available) were used to categorize each patient as being either «stable» or «progressive». Measures of the between-studies percent changes in the choline 1H-MRSI signal intensity, obtained without knowledge of the clinical categorization, segregated the groups with a high degree of statistical significance. All progressive cases showed a between-studies choline signal increase of more than 45%, while all stable cases showed an elevation of less than 35%, no change, or even a decreased signal. We conclude that increased choline coincides with malignant degeneration of cerebral gliomas, and therefore, may possibly be used as a supportive indicator of malignant degeneration of these neoplasms.

Abstract 205: New Onset Heart Failure and Adverse Ischemic Events Associated with Amiodarone and Dronedarone Use among Atrial Fibrillation Patients

2013 ◽  
Vol 6 (suppl_1) ◽  
Author(s):  
Gosia Sylwestrzak ◽  
Jinan Liu ◽  
Alan Rosenberg ◽  
Jeffrey White ◽  
John Barron ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Propensity Score ◽  
Propensity Score Matching ◽  
Incidence Rate ◽  
Statistical Significance ◽  
Administrative Claims ◽  
Risk Of Death ◽  
Observational Cohort ◽  
New Onset

Background: Dronedarone is a non-iodinated form of amiodarone that may not cause some of serious adverse effects associated with amiodarone. However, it is less effective than amiodarone in maintaining normal sinus rhythm, and it does not improve success of electrical cardioversion. Additionally, dronedarone use has been associated with new onset or worsening of heart failure (HF), including a doubling of the risk of death in patients with symptomatic heart failure. We aimed to compare the incidence of newly diagnosed HF and HF hospitalizations among dronedarone and amiodarone users. Secondary outcomes of interest included rates of acute ischemic stroke (IS) and transient ischemic attack (TIA). Methods: This retrospective study utilized administrative claims data between 1/1/2007-9/30/2011 from the HealthCore Integrated Research Environment (HIRE ® ). Patients were required to have at least one claim for atrial fibrillation. Propensity score matching was employed to adjust for differences between the cohorts. Incidence rate of HF, HF hospitalizations, IS and TIA events were compared between matched cohorts using Poisson time-to-event model. Results: The cohort consisted of 6,013 amiodarone and 1,534 dronedarone patients. Dronedarone patients were younger, healthier per Deyo-Charlson Index (DCI) and CHADS2 score, and less likely to have underlying heart disease (all p-values<0.05). In the propensity score matching process 838 patients with comparable baseline characteristics were selected in each group. Median follow up was 552 days in the amiodarone cohort and 412 days in the dronedarone cohort. Among patients without HF history, new onset HF incidence rate was 34.6 per 100 person-year in amiodarone cohort and 19.1 per 100 person-year in dronedarone cohort (IRR=1.61, 95% CI: 1.30-2.01, p<0.01). The incidence rate for HF hospitalization was also higher in amiodarone patients-- 10.7 per 100 person-year against 7.8 per 100 person-year for dronedarone (IRR=1.39, 95% CI: 1.02-1.85, p=0.03). For IS, the incidence rate was 1.68 per 100 person-year in amiodarone vs. 0.84 in dronedarone but results did not reach statistical significance (IRR=1.91, 95% CI: 0.84-4.30, p=0.12); for TIA, it was 3.67 vs. 2.35 for amiodarone and dronedarone respectively (IRR=2.01, 95% CI: 1.14-3.57, p=0.02). Conclusions: In a propensity score matched observational cohort study, amiodarone use was associated with higher incidence rate of new onset HF, HF hospitalizations, and TIA as identified from claims. This finding differs from other clinical studies. Future observational cohort studies should incorporate medical record review for validation since information from claims might be insufficient to fully account for underlying patient risk status, or accurately determine if HF was new onset. Key words: amiodarone; dronedarone; atrial fibrillation; heart failure.

Catheter ablation outscores all other treatment modalities in reducing all-cause mortality and heart failure related morbidity in patients of persistent atrial fibrillation with systolic heart failure

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
D Khanra ◽  
A Mukherjee ◽  
S Deshpande ◽  
D Padmanabhan ◽  
S Mohan ◽  
...  
Keyword(s):  
Heart Failure ◽  
Catheter Ablation ◽  
Meta Analysis ◽  
Statistical Significance ◽  
Systolic Heart Failure ◽  
Individual Treatment ◽  
Published Data ◽  
Bayesian Modelling ◽  
All Cause Mortality ◽  
Pair Wise Comparison

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation in the setting of persistent AF (PeAF) with heart failure (HF) is challenging and often has poor outcome. However, guideline and studies indicate ablation strategy in this group to reduce mortality and HF-related hospitalization. Purpose We have conducted a network meta-analysis (NMA) of all-cause mortality and improvement of HF-related QOL in patients of PeAF with systolic heart failure comparing  rate controlling drugs (RCDs), anti-arrhythmic drugs (AAD), catheter ablation (CA) of PeAF and AV nodal ablation with univentricular or biventricular pacing (AVNA). Method Bayesian network meta-analysis of randomized controlled studies comparing mortality and QOL among individual treatment arms (e.g. RCDs, AADs, CA and AVNA) and pair-wise network meta-analysis comparing CA and other treatment arms (RCD, AAD and AVNA) were performed using MetInsight V3.  Markov chain Monte Carlo (MCMC) modeling was used to estimate the relative ranking probability of each treatment group. Results Published data of 14 studies including 3698 patients were included in the NMA with a median follow-up of two years (1A, 2A). The Bayesian modelling with MCMC analysis for pair-wise comparison clearly demonstrated that, AAD [OR (95% CrI): 2.10 (0.43-9.0)], AVNA [OR (95% CrI): 1.32 (0.14-11.7)] and RCDs [OR (95% CrI): 2.76 (0.5-14.1)] have higher all-cause mortality than CA but not within the radar of statistical significance (1B). The Bayesian modelling with MCMC analysis for pair-wise comparison clearly demonstrated that, AADs [MD (95% CrI): 8.02 (-8.32-27.8)], AVNA [MD (95% CrI): 17.0 (-1.9-33.1)] and RCDs [MD (95% CrI): 13.0 (0.1-24.5)] have lesser improvement in QOL than CA but not within the radar of statistical significance (2B). Based on the Bayesian model, CA results in lower all-cause mortality and highest improvement of QOL in the patients of AF with HF (3A, 3B). Conclusion This shapes way for future treatment guidelines in patients with PeAF with HF group and points towards CA to be undertaken before medical therapy fails. This also paves way for further research to confirm the longevity of the beneficial effects and to find the specific subsets of AF with HF patients that would be benefited most from CA. Abstract Figure

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