Rapid Ventricular Rate Research Articles

Utilization and safety of digoxin in patients with chronic heart failure and atrial fibrillation with rapid ventricular rate

Abstract Background Digoxin can reduce symptoms and the risk of tachycardia-induced cardiomyopathy in patients with heart failure (HF) and concomitant atrial fibrillation (AF) with rapid ventricular rate. The effect of digoxin in HF and AF has not been tested in randomized controlled trials, and observational data have shown conflicting results linking digoxin to increased mortality in AF, though the nature of observational data makes it prone to bias and results difficult to interpret. Purpose To assess the utilization of digoxin in patients with HF and AF, and its association with New York Heart Association (NYHA) functional class and survival. Methods We used data from the Norwegian HF registry that collected data from all Norwegian HF clinics between 2013-2022. Data was collected from the first and last visit during optimizization of HF medical therapy. Associations with mortality status from Statistics Norway were assessed in unadjusted time-to-event analysis, and after adjustment for age, sex, body mass index, estimated glomerular filtration rate, aldosterone antagonists, renin-angiotensin-aldosterone system inhibitors, and beta blockers. Results The study included 4,877 HF patients, consisting of 4,067 (83.4%) with ejection fraction (EF) ≤40% and 810 (16.6%) with EF >40%.. The mean age was 67.7±12.0 years; 25.1% were women, and 27.3% had NYHA functional class III/IV. At the first visit, 1,339 (27.5%) patients had AF and 829 (61.9%) of these were treated with ≥50% of the beta-blocker target dose. AF with a ventricular rate ≥100 bpm was present in 277 (20.1%) patients, and 188 (67.9%) of these were on ≥50% beta-blocker target dose. Similarly, 262 (19.6%) of all AF patients and 44 (15.9%) of those with a ventricular rate ≥100 bpm were treated with digoxin. After optimization of HF medical therapy (median duration 140 [Q1–Q3 82–237] days), 1,039 (21.3%) patients had AF. Among these, 227 (21.9%) were treated with digoxin, including 9 (18.0%) patients with ventricular rate ≥100 bpm. Patients with AF who were started on digoxin experienced during the optimization period a larger decline in heart rate compared to those who were not (mean change -23.7±17.2 vs. -5.7±16.7 bpm, p=0.001), and more often an improvement in NYHA functional class (45% vs 30%, p=0.018). During median 779 [Q1–Q3 386–1,334)] days of follow-up after the last optimization visit, digoxin use was associated with lower mortality in HF patients with AF in unadjusted analysis (HR 0.67 [0.46–0.97]). After adjustment for baseline characteristics and other HF medical therapies, the association with mortality was attenuated and no longer significant (HR 0.96 [0.65–1.42]). Conclusion Digoxin was infrequently used in patients with HF and AF with rapid ventricular rate but was associated with a greater decrease in heart rate and improvement in NYHA functional class. The use of digoxin appears safe and was not associated with increased mortality.

Fatal cerebral thrombosis after pericardiectomy

BackgroundPericardiectomy due to constrictive pericarditis is usually safe procedure. There was a rare event of thrombosis after pericardiectomy, which was mainly accounted by low-cardiac-output syndrome.Case presentationHere, we report the case undergoing pericardiectomy after constrictive pericarditis, with fatal cerebral thrombosis after pericardiectomy confirmed by endovascular mechanical thrombectomy. Even though recanalization was completed and suggestive decompressive craniectomy was in preparation, the patient still died for cerebral hernia due to severe edema. The causes of cerebral thrombosis after pericardiectomy in this case was accounted by the persistence of nonpliable pericardium encasing the left ventricular wall limited local myocardium motor, pro-coagulable state due to thermal transmission during decortication like radiofrequency ablation under the condition of postoperative atrial fibrillation and rapid ventricular rates precipitated the information of mural thrombus in cardiac cavity and migration into the main branch of the aortic arch.ConclusionThe protocol of prompt aggressive anticoagulation prophylaxis would be vigilantly recommended for the patients undergoing pericardiectomy.

6537 Recurrent Graves Thyrotoxicosis After Prolonged Radioiodine-Induced Hypothyroidism

Abstract Disclosure: H.K. Deveaux: None. A. Gundeti: None. K. Mitrollari: None. A.P. Calimag: None. T. Yasmeen: None. Radioactive iodine (I-131) ablation (RAI) is one of the effective therapies for Graves’ disease (GD). Successful treatment is indicated by sustained, irreversible hypothyroidism requiring lifelong replacement for which recurrence of disease rarely develops. Recurrent hyperthyroidism is a rare development without apparent predisposition. Here, we describe a case of recurrent thyrotoxicosis after 36 years of RAI.70-year-old female PMH atrial fibrillation (AFib) on apixaban s/p cardioversion, HTN, HFpEF, Pulmonary HTN, and Graves’ Disease s/p RAI ablation 36 years ago with RAI-induced hypothyroidism. The patient was initially on levothyroxine for post-ablative hypothyroidism and stopped taking levothyroxine around 2019. NM scintigraphy done in 2019 showed an abnormal I-123 thyroid uptake and scan with the five-hour radioiodine thyroid uptake showed mildly hyperthyroid. On the thyroid scan, there is a note of a prominent pyramidal lobe with some thyroid gland asymmetry. In 2022, the patient was admitted for new-onset AFib and was noted to have subclinical hyperthyroidism with TSH 0.157, fT4 1.4, TrAb>40, and TSI 34.8. The patient was started on methimazole, which she stopped one month later. During this admission, the patient presented secondary to a mechanical fall and was found to be in AFib with a rapid ventricular rate. Her labs were significant for TSH<0.008 fT4 4.2, TrAb >40. Methimazole was restarted with maximal doses of diltiazem and metoprolol for rate control. Thyroid ultrasound demonstrated an enlarged, heterogeneous thyroid gland with increased vascularity and multiple bilateral TR3 thyroid nodules.Hyperthyroidism affects approximately 1.2% of the population. GD involves autoantibodies activating the thyrotropin receptor, increasing synthesis and release of thyroid hormone and is for 50-60% of cases with a 5-to-10-fold preference for females. RAI ablation is preferred, being inexpensive, with a cure rate approaching 100%. The incidence of transient hypothyroidism post-RAI varies from 9-17%. Retrospective studies have observed hyperthyroidism within the first 12 months post-RAI; however, some cases have seen a resurgence as late as 22 years later. Recurrent hyperthyroidism is an uncommon occurrence with various postulated aetiologies, such as inadequate dosing/incomplete ablation with residual cells remaining viable and regenerating in the setting of increased TSIiv, Marine-Lenhart syndrome (MLS), or an unclear mechanism associated with autoimmunity in the presence of TSI. Hyperthyroidism rarely recurs in GD after successful post-ablative treatment with RAI. Our case, while an uncommon presentation and underlying aetiology yet to be determined, illustrates the importance of continued surveillance, even after successful treatment.‌ Presentation: 6/3/2024

A STUDY ON ECG FINDINGS IN ACUTE LIVER CELL FAILURE DUE TO RAT KILLER PASTE POISONING

Objectives: The objective of this study was to study the various electrocardiogram (ECG) manifestations in patients who develop acute liver cell failure due to rat killer paste poisoning. Methods: Patients who developed acute liver cell failure due to rat killer paste ingestion admitted during the time period of July 2022–December 2022 in our institution were taken up for the study. Serial ECG monitoring was done in all these patients and observed for any changes. Results: Eighty-eight cases of rat killer paste poisoning that developed acute liver failure during this time period were included in the study. Out of 88 patients, 24 patients (27%) had ECG manifestations. The different ECG manifestations are ST depression with T wave inversion – 13 patients (10 expired), QT prolongation – 8 patients (3 expired), sinus bradycardia – 2 patients, and atrial fibrillation with rapid ventricular rate – 1 patient (expired). The mean time of onset of ECG findings is 22 h from intake of poison. The overall mortality rate is 23% (20 patients). About 70% of expired patients (14 patients) had abnormal ECG manifestations. Conclusion: ST depression with T wave inversion was the most common ECG manifestation due to rat killer paste poisoning in our study and it correlates with mortality. Since cardiotoxicity due to rat killer paste poisoning is also a major contributor to mortality, proper measures have to be taken to create awareness to the general public regarding the toxicity of rat killer paste.

Safety of Diltiazem for Acute Management of Atrial Fibrillation (AF) in Patients with Heart Failure and Reduced Ejection Fraction in the Emergency Department

BackgroundDiltiazem is an effective rate control agent for atrial fibrillation with rapid ventricular rate (AF RVR). However, its negative inotropic effects may increase the risk for worsening heart failure in patients with a reduced ejection fraction (EF). ObjectivesThis observational study aims to describe the incidence of worsening heart failure in patients who receive intravenous diltiazem for acute atrial fibrillation management. MethodsAdult patients that received diltiazem in the emergency department (ED) for AF RVR (heart rate ≥ 100 beats/min) from 2021 to 2022 and had a prior documented EF were included. The primary outcome is worsening heart failure within 24 h of diltiazem administration. Secondary outcomes include return ED visits and death within 7 days. EF percentage was compared across outcomes using Wilcoxon rank-sum tests. Outcomes were compared by reduced EF (< 50%) and preserved EF (≥ 50%). Continuous data were summarized with medians and interquartile ranges, and categorical features were summarized with frequency counts and percentages. Wilcoxon rank-sum tests were used for numeric outcomes and chi-squared tests or Fisher's exact tests for categorical outcomes, with a p-value < 0.05 considered statistically significant. ResultsThere were 674 patients with AF RVR that received diltiazem, and 386 patients met the inclusion criteria for analysis. Baseline demographics included a median age of 72 (64–81) years, with 14.5% of patients having a prior diagnosis of congestive heart failure. EF < 50% was identified in 13.7% of patients (n = 53), of which approximately 30% of these patients safely discharged home after receiving i.v. diltiazem. The primary outcome of worsening heart failure occurred in 7/41 (17%) and 10/207 (4.8%) patients with reduced and preserved ejection fractions, respectively, who were admitted to the hospital (p = 0.005). ConclusionThe development of worsening heart failure is multifactorial and may include the use of diltiazem in critically ill patients requiring hospital admission.

Nonpharmacologic rate control of postoperative atrial fibrillation in the canine sterile pericarditis model.

Postoperative atrial fibrillation (POAF) is common following open heart surgery, and is associated with significant morbidity. Medications used for ventricular rate control of POAF may not be effective in controlling rapid ventricular rates during the postoperative period because of increased sympathetic tone. The purpose of this study was to develop nonpharmacologic rate control of POAF by atrioventricular node (AVN) fat pad stimulation using clinically available temporary pacing wires in the canine sterile pericarditis model. We studied 10 sterile pericarditis dogs in the closed-chest state on postoperative days 1-3. The AVN fat pad stimulation (amplitude 2-15 mA; frequency 20 Hz; pulse width 0.03-0.2 ms) was performed during sustained POAF (>5 min). We measured ventricular rate and inefficient ventricular contractions during sustained POAF and compared it with and without AVN fat pad stimulation. Also, the parameters of AVN fat pad stimulation to achieve a rate control of POAF were measured over the postoperative days. Eleven episodes of sustained POAF were induced in 5/10 sterile pericarditis dogs in the closed-chest state on postoperative days 1-2. During POAF, the AVN fat pad stimulation decreased the ventricular rate from 178 ± 52 bpm to 100 ± 8 bpm in nine episodes. Nonpharmacologic rate control therapy successfully controlled the ventricular rate and eliminated inefficient ventricular contractions during POAF for the duration of the AVN fat pad stimulation. The AVN fat pad stimulation output remained relatively stable over the postoperative days. During sustained POAF, nonpharmacologic rate control by AVN fat pad stimulation effectively and safely controlled rapid ventricular rates throughout the postoperative period.

Comparison of the Effectiveness and Safety of Metoprolol and Diltiazem in Atrial Fibrillation With Rapid Ventricular Rate Patients: A Systematic Review and Meta-Analysis.

This study aims to assess the association between intravenous diltiazem and metoprolol in rate control for atrial fibrillation (AF) patients with rapid ventricular rate, focusing on rate control efficacy and hemodynamic adverse events. Following thePreferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, electronic searches were conducted in Embase, PubMed, and Cochrane CentralRegister of Controlled Trials (CENTRAL) until February 20, 2024. The primary outcome was achieving ventricular rate control < 110/min. Secondary outcomes included new hypotension (systolic blood pressure < 90 mm Hg) and bradycardia (heart rate < 60/min). Nineteen studies (three randomized controlled trials and 16 observational studies) were included in this meta-analysis. Pooled analysis showed intravenous metoprolol resulted in a 39% lower rate control attainment compared to diltiazem (OR: 0.61; 95% CI: 0.44 to 0.84; p = 0.002). There were no significant differences in bradycardia (OR: 0.51; 95% CI: 0.22 to 1.22; p = 0.13) or hypotension risk (OR: 1.08; 95% CI: 0.72 to 1.61; p = 0.72) between the two groups. Intravenous diltiazem demonstrated superior rate control efficacy compared to metoprolol in AF patients with rapid ventricular rate. However, no significant differences were observed in safety outcomes, namely, bradycardia and hypotension.

A Case of Cardioversion and Management of Atrial Flutter in the Emergency Department.

Atrial flutter is a supraventricular cardiac arrhythmia commonly characterized by two or three rapid atrial contractions for every ventricular contraction and a rapid ventricular rate that can be identified by a sawtooth pattern on an electrocardiogram. Patients often present with symptoms of heart failure and face the risk of atrial thrombus with a potential for systemic embolization. As such, pharmacologic rate and rhythm control, transesophageal echocardiogram, direct current cardioversion, and anticoagulation therapies may all be required for patient management. This case study provides an example of the patient presentation, exam findings, diagnostic results, and intervention modalities required for the health care provider to manage atrial flutter correctly in the emergency department setting.

Abstract 15948: Highly Suspicious Yet Diagnostically Unrevealing Left Ventricular Free-Wall Rupture Following STEMI

Introduction: Left ventricular wall rupture is a rare but lethal complication following a ST elevation myocardial infarction (STEMI). We present a case of left ventricular free-wall rupture not identified on echocardiography and CT angiography (CTA) despite high suspicion who underwent emergent lifesaving mediastinal exploration and repair. Case: A 52-year-old male with past medical history of hypertension presented with typical chest pain. He was found to have STEMI with 100% left anterior descending (LAD) artery occlusion and underwent percutaneous coronary intervention to mid LAD. Post procedure, he developed atrial fibrillation with rapid ventricular rate, pericarditis, increasing pericardial effusion (Figure 1), and cardiogenic shock. He underwent intra-aortic balloon pump placement with no improvement in hemodynamics and subsequently an Impella 5.5 was placed. On post MI Day 3, he underwent pericardial window in the setting of shock and increasing pericardial effusion. Intraoperative TEE showed signs of tamponade physiology (Figure 2). Repeat echocardiograms and CTA was unrevealing of a rupture. Post MI day 6, he had increasing output from the drains and increasing pericardial effusion with complete right ventricular collapse on bedside echocardiogram. Emergent mediastinal exploration revealed left ventricular (LV) free-wall rupture which was repaired with a bovine patch. Hemodynamics improved and goal directed medical therapy was started. Discussion: Free wall rupture is a rare complication post MI and is reported in only 0.01% of STEMI. It usually occurs within 1 week, majority occurring within 24 h of MI. Small LV wall rupture can be challenging to diagnose on cardiac imaging. This case emphasizes the importance of having a high index of suspicion for diagnosing free wall rupture in patients presenting with hemodynamically unstable pericardial effusion post STEMI. Prompt pericardiocentesis and surgical intervention lead to a good outcome.

Abstract 18434: Amanita Muscaria and Pantherina Withdrawal as a Cause of Lone Atrial Fibrillation

Introduction: The Amanita mushroom family is known for use as a means of suicide or for psychedelic effects. The manifestations of Amanita mushroom poisoning include gastrointestinal poison, cholinergic effects and organ failure. In this paper, we will discuss the first observed study of a patient who developed new onset atrial fibrillation (AF) with rapid ventricular response (RVR) after withdrawal from accidental chronic poisoning of Amanita muscaria and pantherina over the course of three weeks. Case: A 29 year-old male with no prior past medical history presented with three days of palpitations. He began taking A. pantherina and muscaria three weeks prior to help treat sexual addiction. He started with 0.35 mcg twice a day, then doubled the dose after one week, then three days prior to presentation he started taking three grams twice per day. He noticed palpitations as he increased his dose, but then acutely worsened after he stopped taking mushrooms. In the emergency department, he was found to have new onset atrial fibrillation with rapid ventricular rate as well as frequent episodes of nonsustained ventricular tachycardia. An alcohol level and urine drug screen were unremarkable. Thyroid stimulating hormone was within range. His heart rate did not respond to intravenous diltiazem. He was transitioned to an esmolol infusion that responded with rapid improvement in heart rate as well as ventricular ectopy suppression. He eventually underwent a transesophageal echocardiogram and was transitioned to oral beta blocker therapy. He was discharged with no complications and near full recovery. Discussion: A report published in 1869 described the first description of the pharmacological effect of A. muscaria showing it is 143 times more toxic than acetylcholine due to the inability of cholinesterase to hydrolyse or inhibit its effect. The acute cardiovascular toxicities are well described, however, this case is the first description of chronic cardiac toxicity manifesting as new onset AF with RVR, caused by A. muscaria and pantherina withdrawal. We suggest that cardiovascular monitoring, including event monitors, are essential for complications of A. muscaria and pantherina . More detailed studies need to be done.

Abstract 15597: Unlocking Rate Control in Atrial Fibrillation: A Closer Look at the Intravenous Diltiazem and Metoprolol Duel - An Updated Systematic Review and Meta-Analysis

Background: Intravenous beta-blockers and calcium channel blockers remain first-line therapeutic agents for hemodynamically stable atrial fibrillation patients with a rapid ventricular rate (AF-RVR) in emergency medical settings. Material and Methods: We conducted a thorough review of various sources, including PubMed, Embase, Cochrane databases, and clinicaltrials.gov registry. Our search covered the period from the inception of these databases up to May 20, 2023. We only selected studies that compared the effectiveness and safety of diltiazem and metoprolol in adult patients with AF-RVR who were in emergency medical settings or hospitalized. We focused on whether the drugs successfully controlled heart rate and if there were any cases of hypotension or bradycardia following drug administration. Results: Among the 150 identified studies, 19 were suitable. All these studies demonstrated a low to moderate risk of bias. The meta-analysis, using the Mantel-Haenszel random-effects model, revealed a higher success rate in achieving the rate control target with diltiazem compared to metoprolol [19 studies, n = 1732, Odds Ratio (OR): 1.65; 95% Confidence Intervals (CI):1.18 to 2.32; I^2 = 58%, P = 0.001]. In terms of safety, no significant difference was observed in the risk of hypotension with either drug [15 studies, n = 1477, OR: 1.12; 95% CI: 0.76 to 1.64; I^2 = 25%, P = 0.18]. However, an incidence of bradycardia was noticed with diltiazem [7 studies, n = 1203, OR: 2.85; 95% CI: 1.25 to 6.46; I^2 = 21%, P = 0.27]. Conclusions: For patients with AF-RVR, intravenous diltiazem was more successful in achieving the desired rate control than metoprolol. Both drugs had similar rates of hypotension, but diltiazem had a slightly higher risk of bradycardia. These results indicate that diltiazem may be a better option for rate control in AF-RVR patients. However, high-quality randomized studies are needed to assess both medication's long-term safety and effectiveness in this group.

FRI500 Atypical Case Of Undifferentiated Shock

Abstract Disclosure: V. Vadini: None. P. Vasistha: None. Introduction: Shock is encountered frequently in the ICU. Undifferentiated shock, however, poses a diagnostic challenge. The differentials and work up are broad and time sensitive. Endocrinopathies are a known etiology but thyroid cardiomyopathy causing cardiogenic shock is rare. Clinical case: A 78 y old man presented to the ER with hypotension that did not improve after administration of 2.5 L IV fluids. Vasopressors were initiated and he was admitted to the ICU. Patient reported 2-month history of generalized weakness, nausea, vomiting, falls and poor oral intake. Review of systems was notable for 20-pound weight loss in 6 months, dyspnea with exertion, loss of appetite and occasional diarrhea. On exam, patient was afebrile, hypotensive 80/40, PR 87, O2 saturation &amp;gt; 90% on room air. He appeared pale with JVP measured at 11 cm of water. Pulse was irregular, heart sounds normal without murmurs. Bilateral lower extremities were mildly edematous. Strength in lower extremities was 4/5 proximal and distally. Labs were notable for normocytic anemia, troponin 1.05, elevated anion gap 18, lactate 1.8, creatinine 3.3 from a baseline of 1 and BNP 1425. ECG showed sinus rhythm with frequent premature atrial contractions. Chest Xray on admission was unremarkable. Additional labs were negative drug screen, normal cortisol, urinalysis. Blood cultures were sent. Overnight, the patient developed tachycardia and atrial fibrillation with rapid ventricular rate. Cardiology was consulted, bedside echo was suspicious for low left ventricular ejection fraction. The patient was anticoagulated with heparin. TSH was sent. He was requiring 2 vasopressors to maintain MAP&amp;gt;65. CT chest abdomen pelvis was unremarkable except stable pulmonary nodule. Patient became hypoxic on Day 2 of admission, CXR now showed features of pulmonary edema. TSH returned less than 0.01, free T4 4.69 Endocrinology was consulted, methimazole was started for thyrotoxicosis. Formal TTE showed LVEF 20-25% with global reduction in left ventricular contractility, dilated left atrium and mild MR. He was given furosemide for pulmonary edema. TSI and TRAB were positive indicating Grave’s disease. He was successfully transferred out of the ICU. Patient gradually became euvolemic with significant improvement in energy, appetite and functional capacity. He was able to participate in physical therapy and was eventually discharged to rehab. Conclusion: This case addresses an uncommon but potentially life-threatening cause of undifferentiated shock. Physical exam, history and high degree of suspicion are key in early identification and treatment. Although thyroid cardiomyopathy is rare, Grave’s disease is common and ruling our thyrotoxicosis should be included in preliminary work up of undifferentiated shock. Presentation: Friday, June 16, 2023

SAT566 A Rare Case Of Aggressive Anaplastic Thyroid Presenting As Thyrotoxicosis

Abstract Disclosure: A. Al-Juboori: None. Y. Al-Yousif: None. S. Fomin: None. M. Sundaram: None. Background:Anaplastic Thyroid cancer is a rare neoplasm with a poor prognosis and high mortality rate. Usually, it presents with symptoms like dysphagia and hoarseness. However, it is rarely presented with thyrotoxicosis from the rapid destruction of thyroid follicle cells, causing excessive leakage of preformed thyroid hormones into the circulation. Clinical presentation can vary from a subclinical state to a life-threatening thyroid storm. Management requires an inter-professional team approach. Clinical Case:77-year-old female patient, who visited the urgent care on August 12 complaining of sore throat, Amoxicillin was prescribed. Presented to ER 10 days later complaining of a headache, gum discomfort, shortness of breath, worsening sore throat, neck pain, and gradual worsening dysphagia to liquids and solids. Physical exam revealed anterior painful and firm neck mass upon palpation. Stridor was noted upon auscultation and was found to be in arterial fibrillation with a rapid ventricular rate for which Amiodarone drip and heparin drip were initiated. IV hydrocortisone 50 mg TID was added to the treatment right away for symptomatic relief. The results of the thyroid function test revealed an increased serum FT4 and FT3, and low serum TSH. Antibodies were normal. Clinical presentation increases the suspicion of undifferentiated thyroid cancer versus lymphoma. CT revealed leftward tracheal deviation along with a big undetermined right thyroid mass with accompanying cervical and supraclavicular adenopathy. IR was consulted urgently for a thyroid biopsy. High-grade anaplastic cancer was discovered after a biopsy with metastasis to the surrounding lymph. The decision was made to transfer the patient to a tertiary care facility for invasive interventions. Anaplastic thyroid cancer accounts for 2-3% of all thyroid gland neoplasm, it often affects persons over the age of 60, and the mean age at the time of diagnosis is 65 years, most common in female population compared to males with a ratio of 2:1. There have been only around 9 other cases reported in the literature in which thyrotoxicosis is the initial presentation of anaplastic thyroid cancer. Diagnosis is usually made via core needle biopsy. 70% of individuals with anaplastic thyroid carcinoma will have contiguous spread and distant metastasis at the time of diagnosis. It most commonly compresses the trachea and esophagus. Given the rapid progression of illness, patients can die from local airway obstruction. Average survival is just 6 months with only 1 in 5 people surviving after 12 months. Conclusion:Anaplastic thyroid cancer-induced thyrotoxicosis is an uncommon and rare presentation of thyroid neoplasm. Debulking surgery is the cornerstone for removing tumors and securing the patient’s airway along with controlling thyrotoxicosis. A low survival rate was reported in these patients. Presentation: Saturday, June 17, 2023

Lone atrial fibrillation: A case report on a rare complication of pregnancy

Atrial fibrillation (AF) is one of the most common arrhythmias and is a rare phenomenon seen in pregnant patients unless there is an underlying cardiopulmonary abnormality. Lone AF in pregnancy is a diagnosis of exclusion. A thorough workup including history, physical examination, imaging, and laboratory workup should be done diligently to exclude cardiopulmonary diseases (like hypertensive heart disease, congenital heart disease, valvular heart disease, asthma or chronic obstructive pulmonary disease, pulmonary embolism, rheumatic heart disease) and non-cardiac diseases (such as hyperthyroidism or electrolyte abnormalities or medications). There are very few case reports and studies published so far on this topic. This case report is on a pregnant patient without any significant past medical history who developed new-onset lone AF without any known cause and was managed with Diltiazem, which resulted in chemical cardioversion of atrial fibrillation with rapid ventricular rate to normal sinus rhythm.

Safety and Efficacy of Nondihydropyridine Calcium Channel Blockers for Acute Rate Control in Atrial Fibrillation with Rapid Ventricular Response and Comorbid Heart Failure with Reduced Ejection Fraction.

The use of nondihydropyridine calcium channel blockers (NDCCBs) to achieve rate control in atrial fibrillation with the rapid ventricular rate (AF RVR) is not recommended in patients with comorbid heart failure with reduced ejection fraction (HFrEF) due to the concern for further blunting of contractility. However, these recommendations are extrapolated from data examining chronic NDCCB use in HFrEF patients, and comorbid AF was not analyzed. These recommendations also do not cite the hemodynamic effects or clinical outcomes of NDCCBs for acute rate control in HFrEF patients with AF RVR. It is our goal to open the discussion concerning the hemodynamic effects and safety profile of NDCCBs for acute rate control in this specific patient population. In the acute setting of AF RVR and HFrEF, there is a paucity of low-quality data on the safety and hemodynamic effects of NDCCBs, with mixed results. There has not been a clear signal toward adverse outcomes with NDCCBs, particularly for diltiazem. Data in this scenario is similarly limited for beta blockers, which provide the additional hemodynamic effect of the neurohormonal blockade, which provides a long-term mortality benefit to HFrEF patients. We support the cautious use of beta blockers as first-line therapy in clinical settings where an acute rate control strategy for AF RVR is warranted. We also support diltiazem as a reasonable second-line option, though the relative paucity of data calls for further research to validate this conclusion. Verapamil in this setting should be avoided until more data are available.

Ischemic Evaluation in Patients Presenting With Atrial Fibrillation With Rapid Ventricular Rates and Elevated Troponin Levels Does Not Impact Outcomes

Ischemic Evaluation in Patients Presenting With Atrial Fibrillation With Rapid Ventricular Rates and Elevated Troponin Levels Does Not Impact Outcomes

Brady- and tachyarrhythmias in paroxysmal atrial fibrillation: results from long-term continuous electrocardiographic monitoring in RACE V

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Netherlands Cardiovascular Research Initiative: an initiative with support of the Dutch Heart Foundation, and grant support from Medtronic to the institution. MHJPF was funded by a grant from the Karen Elise Jensen Foundation. JCN was supported by a grant from the Novo Nordisk Foundation Background Atrial fibrillation (AF) has been associated with adverse events and constitutes a significant, global healthcare challenge. Paucity exists on the occurrence of brady- and ventricular tachyarrhythmias. Purpose The aim of this predefined sub-analysis of the Reappraisal of Atrial Fibrillation: interaction between hyperCoagulability, Electrical remodelling, and Vascular destabilization in the progression of AF (RACE V) study was to examine the prevalence of brady- and tachyarrhythmias using continuous rhythm monitoring in patients with paroxysmal self-terminating AF (PAF). Methods We identified 417 patients with PAF and at least two years of follow-up in RACE V; 25 patients with pacemakers at baseline were excluded. All remaining patients (n=392) received an implantable loop recorder and performed daily automated and weekly manual transmissions. Throughout follow-up, all detected episodes of tachycardia ≥182 BPM (cycle length ≤330ms) of ≥24 beats, bradycardia ≤30 BPM (cycle length ≥2000ms) of ≥12 beats, and pauses ≥5 seconds were adjudicated by three cardiologists. Results Over 1,272 patient years of continuous rhythm monitoring, we validated 1,940 episodes in 175 patients with paroxysmal self-terminating PAF (45%); 106 (27%) patients experienced AF or atrial flutter (AFL) with a rapid rate, pauses ≥5 seconds or bradycardias ≤30 BPM occurred in 47 (12%) patients (figure 1), and in 22 (6%) patients, both rapid AF/AFL and bradyarrhythmias were observed. No sustained ventricular tachycardias occurred. In the multivariable analysis, age &amp;gt;70 years (HR 2.4, 95% CI 1.4-3.9), longer PQ interval (HR 1.9, 1.1-3.1), CHA2DS2-VASc score ≥2 (HR 2.2, 1.1-4.5), and treatment with verapamil or diltiazem (HR 0.4, 0.2-1.0) were significantly associated with bradyarrhythmia episodes. For tachyarrhythmia episodes, age &amp;gt;70 years was associated with a significantly lower tachyarrhythmia risk (HR 0.4, 95% CI 0.2-0.7) in the multivariable analysis. Conclusions In a cohort exclusive to patients with self-terminating PAF, severe bradyarrhythmia episodes or AF/AFL with rapid ventricular rates occurred in 45% of patients. Our data highlight a higher than anticipated bradyarrhythmia risk in PAF.

New-Onset Atrial Fibrillation in the Setting of COVID-19 Infection Is a Predictor of Mortality in Hospitalized Patients: CovAF-Study.

Recent studies show that hospitalized COVID-19 patients have an increased incidence of arrhythmia, especially atrial fibrillation (AF). This single-center study included 383 hospitalized patients with positive polymerase chain reaction tests for COVID-19 from March 2020 to April 2021. Patient characteristics were documented, and data were analyzed for episodes of AF on admission or during the hospital stay, intrahospital mortality, need for intensive care and/or invasive ventilation, inflammatory parameters (hs-CRP, IL-6, and procalcitonin), and differential blood count. We demonstrated that in the setting of hospitalized cases of COVID-19 infection, there is an incidence of 9.8% (n = 36) for the occurrence of new-onset AF. Furthermore, it was shown that a total of 21% (n = 77) had a history of episodes of paroxysmal/persistent AF. However, only about one-third of patients with pre-existing AF had relevant documented tachycardic episodes during the hospital stay. Patients with new-onset AF had a significantly increased intrahospital mortality compared to the control and the pre-existing AF without rapid ventricular rate (RVR) group. Patients with new-onset AF required intensive care and invasive ventilation more frequently. Further analysis examined patients with episodes of RVR and demonstrated that they had significantly elevated CRP (p < 0.05) and PCT (p < 0.05) levels on the day of hospital admission compared to patients without RVR.

MP-453091-1 EFFECT OF ETRIPAMIL NASAL SPRAY ON VENTRICULAR RATE IN PATIENTS EXPERIENCING SYMPTOMATIC ATRIAL FIBRILLATION

Atrial fibrillation (AF) is often associated with symptomatically rapid ventricular rates (RVR), for which there is no rapid-onset, at-home treatment approved. Intranasally self-administered etripamil is a calcium channel blocker that has rapid-onset of action and prolongs refractoriness in the AV-node. To determine whether etripamil is safe and effective in acutely reducing RVR in patients with electrocardiographically (ECG) documented AF. NODE-303 is an open-label study evaluating self-administered etripamil, by patients with symptomatic recurrent episodes of paroxysmal supraventricular tachycardia (PSVT). Continuous ECGs were acquired at the onset of symptoms and patients annotated time of drug receipt (70 mg) on the recording. Central examination of ECG data showed that 26 (n=21 patients) of 1024 episodes of treated perceived PSVT involved AF with RVR rather than PSVT. Differences between initial VR and VR at 1-min following intervals were calculated for each episode over the 60 min post drug receipt. VR data after a conversion to sinus rhythm (SR) were excluded. The differences at each timepoint were averaged and are reported and plotted as a delta ± standard error of the mean (SEM) (Fig. 1). Twenty-one AF episodes had sufficiently interpretable ECG data and were analyzed. At baseline, defined as the start of ECG recording, mean VR ± SEM = 129.7 ± 5.4 bpm. Of the 21 AF episodes, 17 had a VR ≥110 bpm at baseline, mean VR ± SEM =138.3 ± 4.3 bpm. The time of drug receipt was estimated to be at start of ECG recording in 12 of 21 episodes. Six episodes converted to SR during the 60 min window, without conversion pauses >2 sec. Averaged reductions in VR from baseline (deltas) were observed throughout the 60-min window, maximally (-27.4 ± 6.1 bpm) at 22 min, and -16.2 bpm ± 5.6 at 60 min (Fig. 1). The upper bound of the SEM did not traverse the baseline over the 60-min. Etripamil was well-tolerated and there were no serious adverse events. In patients with AF and RVR, etripamil, self-administered as prompted by symptoms, resulted in a reduction in VR that was sustained over 60 min, with a timing aligned with the known timing of pharmacologic action of etripamil. No safety problems were observed with administration of etripamil in AF in this data set. These findings warrant further study and suggest a potential role for the drug for acute control of RVR in patients with AF.

Abstract #1405991: Graves’ Disease Presenting as Thymic Hyperplasia

Thymic hyperplasia associated with Graves' disease (GD) is well known to thyroidologist, and reported up to 38% of GD worldwide; however, it remains unrecognized in routine clinical practice. Here we report two cases of GD presenting as anterior mediastinum mass, consistent with thymic hyperplasia. I - A 41-year-old female presented with shortness of breath, chest pain, and nausea. She reported palpitations and unintentional weight loss over the last six months. There was no history of thyroid disease. Blood pressure was 162/86 mmHg, heart rate 94/minute, respiratory rate 26 breaths/minute, temperature 36.7 F, and body mass index 23.5 kg/m2. The thyroid was enlarged with mild tenderness. Laboratory showed TSH < 0.005 (0.358 to 3.74 mc IU/mL), free thyroxine 5.54 (0.76 to 1.46 ng/dL), thyroid-stimulating immunoglobulins 407% (0 to 140%). Computed tomography of the chest with contrast revealed an anterior mediastinal mass. GD was diagnosed, and she was started on standard therapy. II - A 54-year-old female presented with worsening shortness of breath, palpitations, and leg swelling for a several weeks. She reported progressive exertional shortness of breath for ten months, intermittent palpitations, fatigue, and weight loss for the last five months. She had a history of hypertension but no history of thyroid disease. At presentation blood pressure was 159/72 mm Hg, heart rate 102 beats/minute, respiratory rate 20/minute, temperature 37.1 F, and body mass index 32.7 kg/m2. She had atrial fibrillation with a rapid ventricular rate. Her examination showed mild bilateral proptosis and non-tender enlarged thyroid. Results showed TSH < 0.005 (0.358 to 3.74 mc IU/mL), free thyroxine 7.23 (0.76 to 1.46 ng/dL), free triiodothyronine 13.2 (2.18 to 3.98 pg/mL), anti-microsomal antibody (TPO) 315 (0 to 60 IU/mL), and thyroid-stimulating immunoglobulins (TSI) 429 (0 to 140%). Computed tomography of the chest with contrast revealed an anterior mediastinal mass. GD was diagnosed, and standard therapy was started. Discussion: Our two cases demonstrate GD-associated thymic hyperplasia later confirmed during hospitalization with MRI imaging. CT-imaging results were available at the same time or earlier than thyroid function tests but did not mention the differential diagnosis of GD or other autoimmune diseases which would help to avoid unnecessary interventions and guide therapy. Both patients were schedule to closely follow up with endocrinology and repeat imaging in about six months to one year is expected to show reduction in thymic size which would support the diagnosis of GD-associated hyperplasia.