scholarly journals Rate Control in Atrial Fibrillation by Cooling: Effect of Temperature on Dromotropy in Perfused Rabbit Hearts

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Karl Mischke ◽  
Markus Zarse ◽  
Christian Knackstedt ◽  
Patrick Schauerte
Keyword(s):  
Atrial Fibrillation ◽  
Heart Rate ◽  
Rate Control ◽  
Therapeutic Option ◽  
Effect Of Temperature ◽  
Significant Drop ◽  
Refractory Periods ◽  
Sinus Cycle Length ◽  
The Mean ◽  
The Impact

Background. Cooling has emerged as a therapeutic option in critically ill patients (especially after cardiac resuscitation) and might also have a negative dromotropic effect in atrial fibrillation. We sought to determine the impact of cooling on electrophysiologic properties of Langendorff-perfused rabbit hearts.Methods and Results. In 20 isolated Langendorff-perfused rabbit hearts, the temperature of the tissue bath was changed between 17 and 42°C. With decreasing temperature, significant increases of the spontaneous sinus cycle length, decreases of the mean ventricular heart rate during atrial fibrillation, and relevant increases of atrial and ventricular refractory periods were observed (ANOVAP<.01).Conclusions. Cardiac hypothermia leads to a significant drop of mean ventricular heart rate during atrial fibrillation. Negative chronotropy and dromotropy induced by moderate cardiac hypothermia might be a feasible therapeutic approach in patients with hemodynamically relevant tachyarrhythmias in a CCU/ICU setting.

Abstract 15303: The Impact of Heart Rate on the Incidence of Cardiovascular Events in Patients With Chronic Atrial Fibrillation: The Fushimi Af Registry

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Moritake Iguchi ◽  
Hisashi Ogawa ◽  
Hirofumi Sugiyama ◽  
Nobutoyo Masunaga ◽  
Mitsuru Ishii ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Heart Rate ◽  
Rate Control ◽  
Cardiovascular Events ◽  
Chronic Atrial Fibrillation ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
The Impact

Purpose: Previous reports suggested that lenient rate control was not inferior to strict rate control among patients with chronic atrial fibrillation (AF). However, the impact of heart rate (HR) on the incidence of cardiovascular events is not clearly understood. Methods: The Fushimi AF Registry, a community-based prospective survey, was designed to enroll all of the AF patients in Fushimi-ku, Kyoto, Japan. At present, follow-up data were available in 3,514 patients (median follow-up period, 842 days). 1,622 patients had chronic AF, and we obtained ECG findings in 1,561 patients. We divided these patients into three groups based on their heart rate; high-HR (HR≥110) (n=179), intermediate-HR (80≤HR<110) (n=695), and low-HR (HR<80) (n=687), and explored the cardiovascular events (composite of cardiovascular death, hospitalization for heart failure, and arrhythmic events). Results: Mean HR was 128±13 bpm, 93±8 bpm, and 67±9 bpm, respectively. High HR group was younger than other groups, but the prevalence of heart failure was the highest (44.7%, 37.0%, 32.3%; p=0.007) and left-ventricular ejection fraction was the lowest (56.5±14.6%, 60.7±11.9%, 62.7±10.5%; p<0.0001). Prescription of beta-blocker (37.4%, 28.9%, 30.0%) and diltiazem (2.8%, 2.9%, 4.2%) was comparable, but prescription of verapamil was the highest in high-HR group (19.0%, 12.4%, 8.0%; p=0.0001), and prescription of digitalis was the highest in low-HR group (14.0%, 18.2%, 23.4%; p=0.005). Mean CHADS2 score was 2.3±1.3, 2.2±1.3, and 2.2±1.4, respectively. In Kaplan-Meier analysis, the incidence of cardiovascular events was higher in high-HR groups than intermediate- and low-HR group (9.2%/year vs 5.8%/year, p=0.02), but was similar between intermediate- and low-HR group (6.2%/year vs 5.4%/year, p=0.3). The incidence of stroke or systemic embolism was comparable between the three groups (2.6%/year, 3.6%/year, 2.4%/year). Cox proportional hazard ratios [95%CI] of high- and intermediate-HR for cardiovascular events compared to low-HR were 1.63 [1.06-2.44] and 1.10 [0.81-1.79], respectively. Conclusions: Among chronic AF patients, the incidence of cardiovascular events was higher in the patients with high-HR, but was similar between intermediate- and low-HR groups.

scholarly journals Circadian variation of variability and irregularity of heart rate in patients with permanent atrial fibrillation: relation to symptoms and rate control drugs

2015 ◽  
Vol 309 (12) ◽  
pp. H2152-H2157 ◽  
Author(s):  
Valentina D. A. Corino ◽  
Pyotr G. Platonov ◽  
Steve Enger ◽  
Arnljot Tveit ◽  
Sara R. Ulimoen
Keyword(s):  
Atrial Fibrillation ◽  
Heart Rate ◽  
Rate Control ◽  
Symptom Severity ◽  
Circadian Variation ◽  
Approximate Entropy ◽  
Mean Amplitude ◽  
Rr Intervals ◽  
Permanent Atrial Fibrillation ◽  
The Mean

The aim of the present study was to evaluate diurnal variations of the variability and irregularity of heart rate (HR) in patients with permanent atrial fibrillation (AF) with and without rate control drugs. Thirty-eight patients with permanent AF were part of an investigator-blind crossover study comparing diltiazem, verapamil, metoprolol, and carvedilol. We analyzed five Holter recordings per patient: at baseline (no rate control drug) and with each of the four drug regimens. HR, variability (SD; percentages of interval differences of successive RR intervals of >20, 50, and 80 ms; and root of the mean squared differences of successive RR intervals), and irregularity (approximate and sample entropy) parameters were computed in 20-min long nonoverlapping segments. Circadian rhythmicity was evaluated using cosinor analysis to each parameter series, which is characterized by the 24-h mean [midline statistic of rhythm (MESOR)] and excursion over the mean (amplitude). Arrhythmia-related symptoms were assessed by a questionnaire measuring symptom severity and frequency. HR and variability parameters showed a significant circadian variation in most patients, whereas only a small minority of the patients had circadian variations of irregularity parameters. Patients with circadian approximate entropy n at baseline had more severe symptoms (symptom severity: 9 ± 4 vs. 6 ± 5, P < 0.05, circadian vs. noncircadian variations). All drugs decreased the MESOR of HR and increased the MESOR of variability parameters. Only carvedilol and metoprolol decreased the normalized amplitude over 24 h of all parameters and HR. In conclusion, HR and RR variability parameters present a circadian variation in patients with permanent AF, whereas few patients demonstrated circadian fluctuations in irregularity parameters, suggesting different physiological mechanisms.

Atrioventricular Junction Ablation for Heart-Rate Control of Atrial Fibrillation

2019 ◽  
pp. 349-356.e3
Author(s):  
Lian-Yu Lin ◽  
Ting-Tse Lin ◽  
Jien-Jiun Chen ◽  
Jiunn-Lee Lin ◽  
Shoei K. Stephen Huang
Keyword(s):  
Atrial Fibrillation ◽  
Heart Rate ◽  
Rate Control ◽  
Heart Rate Control ◽  
Atrioventricular Junction

Heart Rate and Neurological Outcomes in Patients Undergoing Targeted Temperature Management

2020 ◽  
pp. 088506662098250
Author(s):  
Chad M. Conner ◽  
William H. Perucki ◽  
Andre Gabriel ◽  
David M. O’Sullivan ◽  
Antonio B. Fernandez
Keyword(s):  
Heart Rate ◽  
Positive Association ◽  
Targeted Temperature Management ◽  
Temperature Management ◽  
Neurological Outcomes ◽  
Neurologic Outcomes ◽  
Resuscitation Guidelines ◽  
The Mean ◽  
The Impact ◽  
The Relationship

Introduction: There is a paucity of data evaluating the impact of heart rate (HR) during Targeted Temperature Management (TTM) and neurologic outcomes. Current resuscitation guidelines do not specify a HR goal during TTM. We sought to determine the relationship between HR and neurologic outcomes in a single-center registry dataset. Methods: We retrospectively studied 432 consecutive patients who completed TTM (33°C) after cardiac arrest from 2008 to 2017. We evaluated the relationship between neurologic outcomes and HR during TTM. Pittsburgh Cerebral Performance Categories (CPC) at discharge were used to determine neurological recovery. Statistical analysis included chi square, Student’s t-test and Mann-Whitney U. A logistic regression model was created to evaluate the strength of contribution of selected variables on the outcome of interest. Results: Approximately 94,000 HR data points from 432 patients were retrospectively analyzed; the mean HR was 82.17 bpm over the duration of TTM. Favorable neurological outcomes were seen in 160 (37%) patients. The mean HR in the patients with a favorable outcome was lower than the mean HR of those with an unfavorable outcome (79.98 bpm vs 85.67 bpm p < 0.001). Patients with an average HR of 60-91 bpm were 2.4 times more likely to have a favorable neurological outcome compared to than HR’s < 60 or > 91 (odds ratio [OR] = 2.36, 95% confidence interval [CI] 1.61-3.46, p < 0.001). Specifically, mean HR’s in the 73-82 bpm range had the greatest rate of favorable outcomes (OR 3.56, 95% CI 1.95-6.50), p < 0.001. Administration of epinephrine, a history of diabetes mellitus and hypertension all were associated with worse neurological outcomes independent of HR. Conclusion: During TTM, mean HRs between 60-91 showed a positive association with favorable outcomes. It is unclear whether a specific HR should be targeted during TTM or if heart rates between 60-91 bpm might be a sign of less neurological damage.

P3517Failure to achieve adequate heart rate control in women during therapy optimization

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
V Kutyifa ◽  
J W Erath ◽  
A Burch ◽  
B Assmus ◽  
D Bondermann ◽  
...  
Keyword(s):  
Heart Failure ◽  
Heart Rate ◽  
Beta Blocker ◽  
Rate Control ◽  
Beta Blockers ◽  
Heart Rate Control ◽  
Blocker Therapy ◽  
Cardioverter Defibrillator ◽  
Beta Blocker Therapy ◽  
The Mean

Abstract Background Previous studies highlighted the importance of adequate heart rate control in heart failure patients, and suggested under-treatment with beta-blockers especially in women. However, data on women achieving effective heart rate control during beta-blocker therapy optimization are lacking. Methods The wearable cardioverter defibrillator (WCD) allows continuous monitoring of heart rate (HR) trends during WCD use. In the current study, we assessed resting HR trends (nighttime: midnight-7am) in women, both at the beginning of WCD use and at the end of WCD use to assess the adequacy of beta-blockade following a typical 3 months of therapy optimization with beta-blockers. An adequate heart rate control was defined as having a nighttime HR <70 bpm at the end of the 3 months. Results There were a total of 21,453 women with at least 30 days of WCD use (>140 hours WCD use on the first and last week). The mean age was 67 years (IQR 58–75). The mean nighttime heart rate was 72 bpm (IQR 65–81) at the beginning of WCD use, that decreased to 68 bpm (IQR 61–76) at the end of WCD use with therapy optimization. Women had an insufficient heart rate control with resting heart rate ≥70 bpm in 59% at the beginning of WCD use that decreased to 44% at the end of WCD use, but still remained surprisingly high. Interestingly, there were 21% of the women starting with HR ≥70 bpm at the beginning of use (BOU) who achieved adequate heart rate control by the end of use (EOU). Interestingly, 6% of women with adequate heart rate control at the start of therapy optimization ended up having higher heart rates >70 bpm at the end of the therapy optimization time period (Figure). Figure 1 Conclusions A significant proportion of women with heart failure and low ejection fraction do not reach an adequate heart rate control during the time of beta blocker initiation/titration. The wearble cardioverter defibrillator is a monitoring device that has been demonstrated in this study to appropriately identify patients with inadequate heart rate control at the end of the therapy optimization period. The WCD could be utilized to improve management of beta-blocker therapy in women and improve the achievement of adequate heart rate control in women.

scholarly journals PROGNOSTIC ROLE OF ATRIAL FIBRILLATION AND HEART RATE CONTROL IN CHRONIC HEART FAILURE PATIENTS

2013 ◽  
Vol 61 (10) ◽  
pp. E735
Author(s):  
Savina Nodari ◽  
Marco Triggiani ◽  
Laura Lupi ◽  
Alessandra Manerba ◽  
Giuseppe Milesi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Heart Rate ◽  
Chronic Heart Failure ◽  
Rate Control ◽  
Heart Rate Control ◽  
Prognostic Role ◽  
Heart Failure Patients

Abstract 1087: Effects of Oral Gap Junction Conduction-Enhancing Antiarrhythmic Peptide GAP-134 on Experimental Atrial Fibrillation in Dogs

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Gabriel Laurent ◽  
Howard Leong-Poi ◽  
Gordon Moe ◽  
Xudong Hu ◽  
Petsy Pui-Sze So ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Gap Junction ◽  
Electrophysiological Study ◽  
Placebo Treatment ◽  
Refractory Periods ◽  
Percent Change ◽  
Dog Model ◽  
Antiarrhythmic Peptide ◽  
The Mean ◽  
Mechanical Remodeling

Background: Abnormal intercellular communication caused by connexin dysfunction may promote atrial fibrillation (AF). Objective: To assess the effect of the gap junction conduction-enhancing antiarrhythmic peptide GAP-134 on AF inducibility and maintenance in a new dog model of atrial cardiomyopathy. Methods and Results: Twenty four dogs underwent simultaneous atrioventricular pacing (2 weeks at 220 bpm, atrioventricular delay 0 ms), and were randomly assigned to placebo treatment (PACED-PLACEBO; 12 dogs) or oral GAP-134 (PACED-GAP 134; 12 dogs) (starting at day 0). Percent change in left atrial systolic area (Δ% LASA) from baseline to 2 weeks was calculated using trans-esophageal echocardiography. At 2 weeks, animals underwent an open chest electrophysiological study; conduction velocity (CV) when pacing at 150ms cycle length (CL), effective refractory periods (ERP) and AF vulnerability were measured. The mean plasma concentration of GAP-134 was 557 ± 239 nmol/L. GAP-134 increased CV (395.1 ± 63.2 vs 307.8 ± 54.6 mm/s, p<0.01), and shortened ERP at 200ms CL (104.0 ± 8.6 vs 112.8 ± 11.5 ms, P<0.05). GAP-134 significantly reduced AF inducibility [% burst attempts inducing AF] and maintenance [mean AF duration, number of episodes >10min] in dogs with less than 100% ΔLASA (n=5). In dogs with more structural remodeling (ΔLASA ≥100%, n=7), CV increased but AF inducibility was unaffected. Conclusions: Oral GAP-134 prevents CV slowing in a dog model of atrial cardiomyopathy, but attenuates AF inducibility and maintenance only in dogs with less mechanical remodeling.

Abstract P369: Polypharmacy, Adverse Outcomes, and Treatment Effectiveness in Elderly Patients With Atrial Fibrillation

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Aniqa Alam ◽  
Nemin Chen ◽  
Pamela L Lutsey ◽  
Richard MacLehose ◽  
J'Neka Claxton ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Ischemic Stroke ◽  
Elderly Patients ◽  
Rate Control ◽  
Treatment Effectiveness ◽  
Adverse Outcomes ◽  
Pharmacy Claims ◽  
Increased Risk ◽  
The Impact

Background: Polypharmacy is highly prevalent in elderly individuals with chronic conditions, including atrial fibrillation (AF). The impact of polypharmacy on adverse outcomes and on treatment effectiveness in elderly AF patients remains unaddressed. Methods: We studied 338,810 AF patients ≥75 years of age with 1,761,660 active prescriptions [mean (SD), 5.1 (3.8) per patient] enrolled in the MarketScan Medicare Supplemental database in 2007-2015. Polypharmacy was defined as ≥5 active prescriptions at AF diagnosis based on outpatient pharmacy claims. AF treatments (oral anticoagulation, rhythm and rate control) and cardiovascular endpoints (ischemic stroke, bleeding, heart failure) were defined based on inpatient, outpatient and pharmacy claims. Multivariable Cox models were used to estimate associations of polypharmacy with cardiovascular endpoints and the interaction between polypharmacy and AF treatments in relation to cardiovascular endpoints. Results: Prevalence of polypharmacy was 52% (176,007 of 338,810). Patients with polypharmacy had increased risk of major bleeding [hazard ratio (HR) 1.16, 95% confidence interval (CI) 1.12, 1.20] and heart failure (HR 1.33, 95%CI 1.29, 1.36), but not of ischemic stroke (HR 0.96, 95%CI 0.92, 1.00), compared to those not with polypharmacy (Table). Polypharmacy status did not consistently modify the effectiveness of oral anticoagulants. However, rhythm control (vs. rate control) was more effective in preventing heart failure hospitalization in patients not with polypharmacy (HR 0.87, 95%CI 0.76, 0.99) than among those with polypharmacy (HR 0.98, 95%CI 0.91, 1.07, p for interaction = 0.02). Conclusion: Polypharmacy is frequent among elderly patients with AF, associated with adverse outcomes, and potentially affecting the effectiveness of AF treatments. Optimizing management of polypharmacy in elderly AF patients may lead to improved outcomes.

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