Adequate Rate Control Research Articles

Arrhythmias in thyroid dysfunction

Thyroid dysfunction is associated with characteristic changes in heart rate and arrhythmias. Thyroid hormones act through genomic and non-genomic effects on myocytes and influence contractility, relaxation and action potential duration through avariety of mechanisms. Atrial fibrillation is the most common arrhythmia associated with thyroid dysfunction, it occurs in both euthyroidism and hyperthyroidism in clear association with T4 levels. Mechanistically, in the hyperthyroid state, increased automaticity and triggered activity, together with ashortened refractory period and slowing of the conduction speed, lead to the initiation and maintenance of multiple intraatrial reentry circuits. Influences from the autonomic nervous system and hemodynamics controlled by thyroid hormones act as modulators for arrhythmias, which are promoted by acorresponding substrate (significant impact of comorbidities). Concerning therapy, in addition to treating hyperthyroidism, the initial therapeutic focus is on adequate rate control and anticoagulation in patients with ahigh risk of thromboembolism. Ablation of atrial fibrillation can be considered later on, although there is an increased likelihood of recurrence compared to patients without hyperthyroidism.Prolongation of the QT interval and increase in QT dispersion are involved in the formation of ventricular arrhythmias. Epidemiological data suggest an association of elevated T4 levels with ventricular arrhythmias and sudden cardiac death. However, this seems to be mainly relevant for patients with underlying cardiac disease (e.g. ICD users).

Metoprolol versus diltiazem in the emergency department for atrial fibrillation with rapid ventricular response

BackgroundAtrial fibrillation (Afib) is the most commonly treated arrhythmia in the Emergency Department (ED). Multiple guidelines recommend the use of intravenous (IV) beta-blocking (BB) agents or nondihydropyridine calcium channel blockers (Non-DHP CCB) as first line agents for heart rate control. Data regarding optimal first line selection between the agents is lacking. ObjectivesThe primary objective was to determine whether a clinically significant difference exists in achieving rate control and time to rate control between use of IV metoprolol or diltiazem. MethodsThis was a dual center, retrospective, cohort, chart review of patients presenting to the ED from January 1, 2015 to March 1, 2020, who received either IV bolus doses of metoprolol or diltiazem for Afib with RVR. Inclusion criteria: ≥18 years of age, received a bolus dose(s) of IV metoprolol or diltiazem for management in the ED, and ECG confirmed diagnosis of Afib based on ICD 9/10 codes. ResultsAnalyzed 305 patients with 99 patients in the metoprolol group and 206 patients in the diltiazem group. The primary outcome of time to HR ​< ​110 bpm was not statistically significant between metoprolol and diltiazem groups. Rates of adverse events including bradycardia and hypotension were not significantly different. ConclusionThere was no significant difference in the time to adequate heart rate control following administration of IV metoprolol or diltiazem for the treatment of atrial fibrillation with rapid ventricular response.

CE-452776-3 IS RATE CONTROL EVER ADEQUATE? CATHER ABLATION IN RATE CONTROLLED ATRIAL FIBRILLATION WITH REDUCED EJECTION FRACTION

The optimal rate control target for atrial fibrillation (AF) in the setting of heart failure with reduced ejection fraction (HFrEF) is not defined. Prior clinical trials have demonstrated benefits of AF ablation for patients with HFrEF, including recovery in left ventricular ejection fraction (LVEF). However, it is unknown if degree of rate control prior to ablation affects outcomes. To evaluate whether degree of pre-ablation rate control impacts LVEF recovery following AF ablation in patients with HFrEF. A single center, retrospective cohort study of 75 consecutive patients with LVEF ≤35% who underwent first-time ablation for persistent AF at NYU Langone Health between January 2014 and January 2021. Patients were classified as having a LVEF recovery if their post-ablation LVEF was >35%. Proportion of patients with LVEF recovery were compared between multiple rate control cutoffs: 110 bpm, 90 bpm, and 70 bpm. A binomial logistic regression analysis was then performed examining the relationship of pre-ablation HR on LVEF recovery. The mean pre-ablation HR was 90±25 bpm, baseline LVEF was 27±6%, and 64% (48/75) of patients had at least 3 months of maximal GDMT prior to ablation (Table 1A). Significant improvement in LVEF was observed in all patient subgroups irrespective of rate control status (Figure 1A) and regardless of prior GDMT (Figure 1B). Overall, LVEF recovery to >35% occurred in 59% (44/75) of patients. Compared to patients with pre-ablation HR faster than evaluated rate control cutoffs (Table 1B), there were no differences in frequency of LVEF recovery when using ≤110 bpm (controlled: 58% vs. not controlled: 63%, p=0.73) or ≤90 bpm (controlled: 52% vs. not controlled: 66%, p=0.21). In contrast, patients achieving rate control ≤70 bpm were significantly less likely to have LVEF recovery (41%) compared to those with HR above the cutoff (66%; p=0.04). Binomial logistic regression analysis did not reveal HR as a significant predictor of LVEF recovery (OR=1.01; CI 95%=0.99-1.03; p=0.16). Catheter ablation of persistent in AF in patients with HFrEF frequently resulted in improvement in LVEF, irrespective of achieved rate control. LVEF recovery >35% following catheter ablation was reduced only with rate control of HR 70bpm. Catheter ablation should be considered in HFrEF patients regardless of degree of rate control achieved. Heart rate 70bpm should be evaluated as a goal for adequate rate control in patients with HFrEF in whom rhythm control is not pursued.

Measurements of pulse rate using facial video cameras from smart devices in patients diagnosed with atrial fibrillation

Clinical applications of passive long-term heart rate (HR) monitoring in patients with cardiac arrhythmias include adequate drug titration of atrioventricular (AV) nodal drugs and assessment of medical compliance with treatment. A majority of patients treated with beta-blockers, especially patients with atrial fibrillation (AF), require some degree of drug titration during the first 6 months of treatment to ensure that adequate HR control and medicine compliance has been achieved. Failing to achieve adequate rate control in patients with AF can lead to worsening symptoms, heart failure exacerbations, and potentially tachycardia-induced cardiomyopathy. Enabling video-based monitoring during telehealth patient visits could facilitate providers to measure heart rate (HR) without the need for a dedicated home device (smartwatch, SPO2 device, or others). Videoplethysmography (VPG) is a monitoring technology that measures pulse rate by utilizing front-facing cameras embedded in smart devices. VPG provides a remote and contactless cardiac monitoring solution. We conducted a clinical experiment to evaluate the accuracy of VPG in measuring HR while running on two portable devices: Samsung S10 smartphones and S3 tablets. We used a single‑lead ECG to measure the heart rate at the time of the VPG recordings in AF patients. We employed the Bland-Altman method to measure the level of agreement between videoplethysmography and ECG-based measurements of HR. The findings reveal that the mean difference in videoplethysmography and ECG-based heart rate was inferior to 1 bpm across the 2 devices with confidence intervals ranging from 3 to 12 BPM. Our facial video-based HR monitoring solution could assist providers in measuring heart rates in their patients with AF during remote telehealth visits.

MHealth-based assessment of rate control during recurrent paroxysms after an emergency department visit for recent-onset atrial fibrillation: a subanalysis of the RACE 7 ACWAS trial

Abstract Introduction Achieving adequate rate control is a mainstay in the treatment of atrial fibrillation (AF). In the Rate Control versus Electrical Cardioversion Trial 7 – Acute Cardioversion versus Wait and See (RACE 7 ACWAS) trial, an early cardioversion approach was compared to a delayed cardioversion approach for patients with recent-onset symptomatic AF, followed by a four-week monitoring period using mobile health (mHealth). Purpose To assess the adequacy of rate control during recurrences of AF in the four weeks after an emergency department visit for recent-onset AF using mHealth. Methods After restoration of sinus rhythm (spontaneous or through cardioversion), patients (n=335) were asked to record one minute heart rate and rhythm recordings three times daily and in case of symptoms by using an electrocardiographic-based handheld device to monitor for recurrences for four weeks after the index visit. Recordings from the handheld device were collected at the end of the follow-up period. For this subanalysis, a cut-off for lenient rate control during AF recurrences was used and this was defined as a heart rate of &amp;lt;110 beats per minute. A p-value of &amp;lt;0.05 was considered statistically significant. Results mHealth-based monitoring identified 99 patients with a total of 314 recurrences (29.6% of the included patients; median age 67 [interquartile range (IQR) 13] years, 60.6% male, 49.5% delayed cardioversion group, median number of recurrences 2 [IQR 2]). Two recurrences in one patient were excluded from analysis because heart rate could not be adequately assessed due to too much interference. Rate control was always adequate during 126 recurrences (40.4%), always inadequate during 111 recurrences (35.6%) and varying between adequate and inadequate in the remaining 75 recurrences (24.0%). On a patient level, rate control was always adequate in 26 patients (26.5%), always inadequate in 20 patients (20.4%) and varying between or within recurrences in the remaining 52 patients (53.1%) (Figure 1). Although there were no differences in clinical characteristics of the patients based on their adequacy of rate control, there is a trend towards significance regarding randomisation group (p=0.051), with patients with adequate rate control being more often in the delayed cardioversion group compared to those with varying and inadequate rate control (18 (69.2%) vs 24 (46.2%) vs 7 (35.0%), respectively). Conclusion It is feasible to assess heart rate and the adequacy of rate control during recurrences of recent-onset AF using mHealth. Whether real time mHealth-based rate and rhythm monitoring can be integrated in a remote management pathway to adapt rate control in AF patients warrants further studies. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Netherlands Organization for Health Research and Development–Health Care Efficiency Research Program

His-bundle pacing vs biventricular pacing following atrioventricular nodal ablation in patients with atrial fibrillation and reduced ejection fraction: A multicenter, randomized, crossover study—The ALTERNATIVE-AF trial

Atrioventricular nodal ablation (AVNA) combined with biventricular pacing (BVP) improves outcomes in patients with persistent atrial fibrillation (AF), adequate rate control, and reduced left ventricular ejection fraction (LVEF). His-bundle pacing (HBP) delivers physiological ventricular activation and is a promising alternative to BVP. The purpose of this trial was to compare HBP with BVP following AVNA. In this multicenter, prospective, randomized crossover trial, we recruited patients with persistent AF and reduced LVEF (≤40%). All patients underwent AVNA and received both HBP and BVP. Patients were randomized to either HBP or BVP for 9 months (phase 1), then were switched to the alternative pacing modality for the next 9 months (phase 2). The primary endpoint was change in LVEF. Fifty patients (age 64.3 ± 10.3 years; ventricular rate 93.1 ± 19.9 bpm; 72% male) were enrolled. Thirty-eight patients completed the 2 phases and were included in the crossover analysis. A significant improvement in LVEF was observed with HBP compared to BVP (phase 1: ΔLVEFHBP 21.3% and ΔLVEFBVP 16.7%; phase 2: ΔLVEFHBP 3.5% and ΔLVEFBVP -2.4%; Pgeneralizedadditivemodel = 0.015). Significant improvements in left ventricular end-diastolic diameter, New York Heart Association functional class, and B-type natriuretic peptide level were observed with both pacing modalities compared with baseline, whereas no significant differences were observed between HBP and BVP. HBP delivers a modest but significant improvement in LVEF in patients with persistent AF, impaired ventricular function, and narrow QRS duration post-AVNA compared with BVP. Larger long-term trials are required to confirm the additional improvements in function with HBP.

52-Year-Old Woman With Palpitations, Abdominal Distension, and Severe Abdominal Pain

52-Year-Old Woman With Palpitations, Abdominal Distension, and Severe Abdominal Pain

Mapping pleiotropic loci using a fast-sequential testing algorithm

Pleiotropy (i.e., genes with effects on multiple traits) leads to genetic correlations between traits and contributes to the development of many syndromes. Identifying variants with pleiotropic effects on multiple health-related traits can improve the biological understanding of gene action and disease etiology, and can help to advance disease-risk prediction. Sequential testing is a powerful approach for mapping genes with pleiotropic effects. However, the existing methods and the available software do not scale to analyses involving millions of SNPs and large datasets. This has limited the adoption of sequential testing for pleiotropy mapping at large scale. In this study, we present a sequential test and software that can be used to test pleiotropy in large systems of traits with biobank-sized data. Using simulations, we show that the methods implemented in the software are powerful and have adequate type-I error rate control. To demonstrate the use of the methods and software, we present a whole-genome scan in search of loci with pleiotropic effects on seven traits related to metabolic syndrome (MetS) using UK-Biobank data (n~300 K distantly related white European participants). We found abundant pleiotropy and report 170, 44, and 18 genomic regions harboring SNPs with pleiotropic effects in at least two, three, and four of the seven traits, respectively. We validate our results using previous studies documented in the GWAS-catalog and using data from GTEx. Our results confirm previously reported loci and lead to several novel discoveries that link MetS-related traits through plausible biological pathways.

Improving CT-Derived Fractional Flow Reserve Analysis: A Quality Improvement Initiative.

ObjectivesThe aim of this study was to identify factors and quality improvement strategies to improve coronary computed tomography angiography (CCTA) studies referred for fractional flow reserve derived from CT angiography (FFRCT) analysis.MethodsThirty randomly selected CCTAs were analyzed for quality control. A uniform CCTA protocol was implemented by an in-house steering committee, emphasizing the importance of adequate heart rate control and nitroglycerine usage. Sixty additional randomly selected CCTAs were evaluated for quality at multiple time points during intervention, and FFRCT acceptance rate was analyzed at the conclusion.ResultsPrior to the implementation of this quality improvement program, our overall institution-specific percent acceptance rate was 76.1% for FFRCT compared to the national average of >95%. Post-intervention, this was improved to an average acceptance rate of 90% for FFRCT analysis.ConclusionsEstablishment and strict adherence to CCTA imaging protocols with appropriate training and adequate buy-in of CT technologists and nurses is a viable way of improving the quality of imaging and subsequent patient care.

Resting heart rate in ambulatory heart failure with reduced ejection fraction treated with beta-blockers.

AimsCurrent guidelines recommend beta‐blocker therapy in chronic heart failure with reduced ejection fraction (HFrEF) titrated according to tolerated target dose. The efficiency of this strategy to obtain adequate heart rate (HR) control remains unclear in clinical practice. The aim of this study was to determine, in a real‐world setting, the proportion of HFrEF patients who fail to achieve beta‐blocker target doses, whether target doses of beta‐blockers have a relationship with the adequacy in reducing resting HR over time.Methods and resultsBeta‐blocker dose and resting HR of consecutive ambulatory patients with a diagnosis of HFrEF (ejection fraction ≤ 35%) in sinus rhythm were reviewed at the first outpatient contact in the Cleveland Clinic Health System from the year 2000 to 2015. Patients who did not receive beta‐blocker therapy, have congenital heart disease and hypertrophic cardiomyopathy, were not in sinus rhythm, or have a history of heart transplant were excluded. Patients were followed up until their last known visit at the Cleveland Clinic. Median resting HR was 71 b.p.m. [inter‐quartile range (IQR) 60–84 b.p.m.] in 8041 patients (median age 65; 68% male) with 67% on carvedilol, 32% on metoprolol succinate, and 1% on bisoprolol. In 3674 subjects (56%), resting HR was ≥70 b.p.m. At final follow‐up after a median of 21 months (IQR 0.1–7.2 years), resting HR was 72 b.p.m. (IQR 60–84 b.p.m.) in the subset of patients with persistently low ejection fraction ≤ 35%. HR ≥ 70 b.p.m. was observed in 55% of this group. Beta‐blocker target dose was achieved in 19%, 5%, and 15% of those receiving carvedilol, metoprolol succinate, and bisoprolol, respectively. In the subset of patients who experienced beta‐blocker up‐titration, reduced mortality or hospitalization due to heart failure was observed in patients who experienced the lowest HR after titration.ConclusionsIn our single‐centre experience, the majority of patients with chronic HFrEF treated with beta‐blocker therapy did not achieve target doses over time, and a substantial proportion had inadequate control of resting HR. There was no relationship between achieved beta‐blocker target dose and resting HR control.

Atrial fibrillation: a risk factor for unfavourable outcome in COVID-19? A case report

BackgroundFulminant cardiac involvement in COVID-19 patients has been reported; the underlying suspected mechanisms include myocarditis, arrhythmia, and cardiac tamponade. In parallel, atrial fibrillation is common in the elderly population which is at particularly high risk for COVID-19 morbidity and mortality.Case summaryA 72-year-old male SARS-CoV2-positive patient was admitted to the intensive care unit due to delirium and acute respiratory failure. Atrial fibrillation known from history was exacerbated, and made complex rate and rhythm control necessary. Progressive heart failure with haemodynamic deterioration and acute kidney injury with the need for continuous renal replacement therapy were further aggravated by pericardial tamponade.DiscussionTreatment of acute heart failure in COVID-19 patients with a cytokine storm complicated by tachycardic atrial fibrillation should include adequate rate or rhythm control, and potentially immunomodulation.

Abstract 217: Are Discharge Rate Control Medications Adequate for Future Atrial Fibrillation Needs?

Background: Rate control medications (RCM) for atrial fibrillation (AF) usually prescribed are diltiazem (DTZ) and beta blockers. Patients entering the Emergency Department (ED) with AF often convert to a normal sinus rhythm (NSR) by means of spontaneous conversion to normal sinus rhythm (SCNSR), electrical cardioversion, or medications. However, recurrent AF often leads to repeat ED visits and frequent hospitalizations within one year. Goals: To evaluate admission and discharge metoprolol (MTP) and DTZ doses for patients presenting to the ED with rapid AF. Methods: Retrospective, single center chart review of MTP and DTZ doses on admission and discharge for patients admitted with a primary diagnosis of AF. Patients who received new or an increase of other RCMs, or antiarrhythmic medications with RCM properties were excluded. Results: Of 402 patients, 310 (77%) had a heart rate ≥110 bpm on admission. Of those with a rapid rate, 235 (76%) converted to NSR after admission predominantly due to SCNSR. The mean daily dose of MTP was 61mg on admission and 65mg at discharge. The mean DTZ dose on admission was 188mg and 157mg at discharge. Discussion: The discharge doses of 65mg of MTP and 157mg of DTZ were well below the recommended doses of RCMs for AF. The RATAF trial demonstrated adequate rate and symptom control with MTP 100mg/day and DTZ up to 360mg/day. The current study demonstrated significant under dosing of RCMs to manage future rapid ventricular rate. It is possible patients with rapid ventricular rates who convert to NSR, which by itself, results in rate control, would not have attention by the provider focused on the rapid admission rate. Most patients who convert to NSR do not have the substrate leading to AF corrected. Thus, it is not surprising recurrence of AF, regardless of the method of cardioversion, occurs in approximately 70% of patients within one year. It is likely when AF recurs it will have the same rapid rate unless RCMs are increased before discharge from the first initial admission dose. It is possible at discharge an order set may lead to a more logical assessment of targeted RCMs. Lack of long term follow-up to address outcome of apparent under dosing of RCM is a limitation. Conclusion: This single center study found no significant increases in MTP and DTZ dosing at the time of discharge for patients with rapid AF who reverted to NSR after admission. It is possible that modification of RCMs before hospital discharge may decrease future ED admission for symptomatic AF.

Abstract P198: Connected Health Remote Monitoring in Atrial Fibrillation Care Management

Background: Avoiding early hospital readmission after a diagnosis of atrial fibrillation (AF) lowers healthcare costs. Purpose: This investigation pilot tested the process of using a Connected Health (CH) communication platform in AF care management. Subjects: A self-selected group of patients (n=18, 56% male, mean age=69 years, SD =12.6) diagnosed with hemodynamically stable AF and an uncontrolled ventricular response with heart rates &gt; 110 bpm were recruited. MethodS: Eligibility criteria included a recent AF related emergency department or outpatient clinic visit and the new prescription of a rate control medication. This included AV node modifying medications (either a beta blocker or nondihydropyradine calcium channel blocker) at a starting dose determined by the supervising physician. A care management team (CMT) coordinated by a nurse practitioner provided individualized telephone medical management with no planned clinical visits during a period of early recovery. Patients were equipped with the AliveCor TM Kardia electrocardiogram (ECG) home monitoring device and a supporting mobile device application. Patients returned home with medical guidance from the CMT and ECG recording instructions. Heart rate and rhythm were monitored remotely by the NP and the medication dose was adjusted to reach a target resting heart rate &lt;110 bpm. Patients were managed for 3-weeks before being discharged back to primary care or outpatient cardiology for consideration of a rate versus rhythm control strategy if spontaneous restoration of sinus rhythm had not occurred. ResultS: Patients recorded an average of 50 ( SD =40.0) ECG tracings with a mean of 13 ( SD =3.79) related CMT telephone contacts. The mean resting heart rate was significantly lower ( p &lt;0.05) at the completion of the intervention (72.9 bpm, SD =17.31) compared to baseline (102.3 bpm, SD =27.17). All of the AF patients achieved adequate heart rate control or spontaneously returned to sinus rhythm. However, 4 patients (22%) required a related emergency room visit and unplanned hospitalization. Conclusion: In this small feasibility study, an electronic healthcare device (biosensor) paired with a mobile-heath application provided a practical remote monitoring communication platform to support tele-management, but the intervention did not prevent hospital readmission. Future Directions: Further research is needed to identify factors that will improve the process of applying CH to AF care management.

Adequate Usage Rate Control of Switching Cycles for DCM Buck PFC Converter

Buck power factor correction converter is widely used in low-power applications due to its specific advantages. In discontinuous conduction mode operation, the inductor current is zero during part of the switching cycle, leading to a useless period in the whole switching cycle of the power transmission. As a result, the peak value and the root-mean-square (RMS) value of the inductor current as well as the switch current are large. In addition, the current stress of the power devices is high, and so does the switching loss. A new method called adequate usage rate control of switching cycles to improve the effect of the energy transfer is proposed. Compared with the fixed duty ratio control, the critical inductance is increased, and the peak and rms current values of the main power components are reduced. Therefore, the efficiency of the converter is increased. The method brings about higher PF at low input voltages and lower PF at high input voltages. Meanwhile, a reduction of the output ripple voltage is achieved. A prototype is fabricated in the laboratory, and the experimental results are presented to verify the effectiveness of the proposed method.

P184 Broken heart complications

Abstract Introduction Patients with persistent chest discomfort or other symptoms suggestive of ischaemia and ST segment elevation in two contiguous leads on electrocardiography should be prompt managed to revascularization and emergent angiography for percutaneous intervention in two hours is the preferred reperfusion strategy. Purpose Our aim is to show the importance of differential diagnosis in a patient with an initial diagnosis of ST segment elevation myocardial infarction (STEMI). Clinical case We present a case of 67 years old women with a past medical history of dyslipidemia and polymyalgia rheumatica, treated with rosuvastatin 10mg id and prednisolone 5 mg id. The patient was admitted to emergency department complaining of chest pain with 3 hours of evolution that started after a period of nausea and vomiting. Physical examination showed slight tachypnea with 22 breath per minute, blood pressure 93/40 mmHg, heart rate 110 beats per minute, oxygen saturation in room air 90%, heart sounds with a systolic murmur II/VI and lung crackles in inferior lobes, with no peripheral oedema. Electrocardiography showed sinus rhythm and ST segment elevation in DI, DII and V2-6. Patient was treated with aspirin 300mg, ticagrelor 180mg, furosemide 40mg, oxygen therapy and was scheduled for emergent coronariography. This procedure revealed no significant coronary lesions and ventriculography identified apical ballooning, diagnosing takotsubo myocardiopathy. Clinical condition starts to deteriorate, and an echocardiography identified akinetic apical and midventricular segments and hyperkinetic basal segments with systolic anterior motion of mitral valve, significant mitral regurgitation and left ventricular outflow tract obstruction (LVOTO) with an intraventricular gradient superior to 60 mmHg. Adequate hemodynamic monitoring and heart rate control allowed a substantial clinical improvement. Two days later a cardiac magnetic ressonance was done, confirmed the diagnosis and identified an apical thrombus. The patient was later discharged stable with oral hypocoagulation with anti-vitamin K antagonist. Discussion and Conclusion Takotsubo cardiomyopathy is a unique cardiac syndrome characterized by transient systolic dysfunction witch often mimics acute coronary syndromes (ACS). After exclusion of an ACS, echocardiography is of primordial importance in the assessment of these patients. Left heart failure with pulmonar oedema, mitral regurgitation, LVOTO and thrombus formation were all complications that were present in this clinical case and established the indication to proper therapeutic attitudes. Abstract P184 Figure.

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

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 &lt;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 (&gt;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 &gt;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.

P2281Inadequate heart rate control begets sustained ventricular arrhythmias in a large cohort of women

Abstract Background The Wearable Cardioverter Defibrillator (WCD) is an effective therapy for treating ventricular arrhythmias (VT/VF) in at-risk patients, while providing continuous heart rate (HR) monitoring. Because women are under-represented in defibrillator trials, we chose to specifically focus on HR control in women prior to VT/VF events. Purpose To evaluate HR profiles preceding sustained VT/VF in women fitted with a WCD. Methods Data from women fitted with WCD (≥30 days use) from 2015 to 2018 were obtained from the manufacturer's database. HR is expressed as a weekly resting nighttime median (midnight to 7 am). Men (random sample) with the same inclusion criteria served as a control. Results A total of 21,440 women, age 67±15 years, were included for analysis. Over a median WCD use of 90 days (59–116 days), 118 women (0.6%) and 133 men (0.8%) received shocks for VT/VF (p=0.01). Resting HR one-week preceding VT/VF was above the target of 70bpm in 55% of shocked women (65 of 118) versus 44% of non-shocked women (9,272 of 21,322, p=0.01) (figure). HR one week before WCD shock was similar in women and men (71 bpm vs. 72 bpm; p=0.60). Younger women (≤50 years) had higher HR prior to shock than older women (HR 80 bpm vs. 70 bpm p=0.003). Among shocked patients, 24-hour-survival was 89% in women and 88% in men. During three-month follow-up, the same percentage of men and women died after receiving adequate WCD shock therapy (18%). Heart rate profiles Conclusions Women with adequate heart rate control experienced significantly less spontaneous VT/VF than those with higher heart rates. The WCD can be utilized as a diagnostic tool to monitor HR in at-risk women in addition to treating sustained VT/VF.

Failure to Achieve Adequate Heart Rate Control in Women during Therapy Optimization

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 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). 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.

DERIVATION AND VALIDATION OF THE CONTINUE-ONE-TWO-HOLD PROTOCOL FOR OPTIMIZING PERI-CARDIOVERSION RATE CONTROL MEDICATIONS

Most patients with atrial fibrillation (AF) are prescribed rate control medications . There are no guidelines for adjustment of these medications prior to electrical cardioversion (DCCV). We sought to derive and validate a pre-procedural medication adjustment protocol that maintains peri-cardioversion rate control and avoids bradycardia, conversion pauses, need for pacing, and CPR after DCCV. Retrospectively derived and prospectively validated an algorithm in patients undergoing DCCV at our multidisciplinary AF clinic. Each patient taking an AV nodal blocker was given adjustment instructions based on their ECG heart rate two days before DCCV. Medication dosages were standardized based on dose equivalency tables (Table 1). The magnitude of dosage reduction was compared with peri-cardioversion heart rates, where rate control was considered adequate if the 30-minute pre-DCCV and five-minute post-DCCV heart rates were both within 50 to 100 bpm. In the derivation cohort, we assessed the effectiveness of all medication adjustment strategies and evaluated which strategy was effective for the highest proportion of patients from 2015 to 2017. This strategy was then prospectively evaluated as a protocol in the validation cohort for one year onwards. Patients with atrial flutter or pacemaker were excluded. A total of 71 patients were included in the derivation cohort (mean age 65.5 ± 10.3 years; 73% male). The strategy with the highest proportion of patients achieving adequate peri-cardioversion rate control was i) CONTINUE AV nodal blocker when two-day pre-DCCV heart rate ≥100 bpm, ii) reduce dose by ONE increment when 80 to 99 bpm, iii) reduce dose by TWO increments when 60 to 79 bpm, and iv) HOLD when <60 bpm. When this CONTINUE-ONE-TWO-HOLD protocol (Figure 1) was evaluated in the validation cohort of 48 consecutive patients (mean age 63.1 ± 10.1 years; 77% male), 37 (77%) patients achieved adequate peri-cardioversion rate control. Proportion of patients with post-procedural bradycardia was significantly reduced from 69% to 48% between cohorts (P=0.02). Of the 11 inadequate cases, four patients had pre-DCCV heart rates >100 bpm and 2 had post-DCCV heart rates <50 bpm, but these patients were already experiencing tachycardia and bradycardia respectively before medication adjustment. There were no conversion pauses ≥five seconds, need for pacing, or CPR post-procedure in patients following the CONTINUE-ONE-TWO-HOLD protocol in either cohort. The CONTINUE-ONE-TWO-HOLD protocol is a feasible and effective pre-procedural strategy of optimizing medications for peri-cardioversion rate control in patients with AF.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Is There Still a Role for Digoxin in the Management of Atrial Fibrillation?

A number of recent observational analyses have assessed clinical outcomes associated with digoxin use in patients with atrial fibrillation. In this review, we review these data and provide suggestions on the contemporary use of digoxin in patients with atrial fibrillation as supported by the recent evidence. Observational data from clinical trials and registries have provided variable results on the safety and efficacy of chronic digoxin use in patients with atrial fibrillation. In general, results have been consistent with an associated increase in adverse clinical outcomes with digoxin use in atrial fibrillation patients without heart failure. In atrial fibrillation patients with heart failure, while the weight of evidence suggested an associated risk with digoxin therapy, the results are inconsistent. In patients with atrial fibrillation without heart failure, digoxin should generally be avoided. In atrial fibrillation patients with heart failure, digoxin should generally be reserved for patients that do not achieve adequate rate control or are not tolerant of other rate control therapies.