Cardioneuroablation in a Woman with Ictal-Induced Cardiac Asystole

Background: Ictal-induced cardiac bradyarrhythmia and asystole is a rare phenomenon. The exact mechanism of ictal-induced cardiac bradyarrhythmia and asystole remains unclear. It was postulated that stimulation of central autonomic network during ictal episode may trigger an abrupt burst of hypervagotonia. Prolonged episode of cardiac bradyarrhythmia and asystole may result in syncope or death due to impairment of cerebral perfusion. The role of cardioneuroablation (CNA) in this condition has not been well-described in the literature. Objective(s): To describe a case of successful CNA in a patient with ictal-induced bradyarrhythmia and asystole. Method(s): n/a Results: A 47-year-old female has a 1.5-year history of intractable focal epilepsy and COVID-19 infection. She started having multiple episodes of seizures following a mild COVID-19 infection. Electroencephalogram (EEG) and brain MRI revealed right temporal onset seizures without structural lesions. Due to ongoing uncontrolled seizures with multiple semiologies despite multiple anti-epileptic drugs, she was admitted to Epilepsy Monitoring Unit for seizure classification. Her ictal EEGs (Figure 1) showed onset of ictal rhythm in the right temporal region with episodes of severe sinus bradycardia (15-30 bpm) and sinus pauses (15-16 seconds). Telemetry tracings demonstrated PP interval slowing with PR interval prolongation prior to the pauses consistent with a vagally-mediated mechanism. Cardiac electrophysiology team recommended CNA for treating the episodes of ictal-induced bradyarrhythmia and asystole. 3D anatomic maps of the right atrium (RA) and left atrium (LA) were created using CARTO system (Biosense Webster). Right superior ganglionated plexus (RSGP) was localized with fractionation mapping and intracardiac echocardiography guidance. RSGP was targeted from the RA using an irrigated radiofrequency catheter with power limit of 25 W. Post-ablations of RSGP, her heart rate increased from 60 - 99 bpm. Additional lesions were delivered from the LA site but no additional heart rate increase was not seen. An implantable loop recorder was implanted post-ablation procedure. During follow-up of 8 months, she had recurrent focal epilepsy, but no bradyarrhythmias or asystole was noted on her loop recorder. Resting heart rates at long-term follow up were between 70 - 100 bpm. Conclusion(s): This case highlights the utility of CNA in patient with ictal-induced cardiac bradyarrhythmia and asystole. CNA may be an approach to avoid permanent pacemakers in this population. [Formula presented]Copyright © 2023

Complete Atrioventricular Block in COVID-19-Related Myocarditis: A Case Report

Myocarditis accompanied by a high-grade atrioventricular (AV) block is a rare manifestation of COVID-19 infection. A 53-year-old woman presented with an episode of syncope, dyspnea, dry cough, and fever. On physical examination, the patient had high blood pressure and bradycardia. Her electrocardiography displayed a complete AV block with a junctional escape rhythm. Laboratory investigations revealed leukocytosis, elevated D-dimer, a positive SARS-CoV-2 nasopharyngeal swab, and a significant elevation in troponin. No reversible cause of the AV block was found, and the complete AV block persisted after the complete treatment of COVID-19. A His bundle permanent pacemaker was then implanted. An endomyocardial biopsy demonstrated endomyocardial tissue with focal hemorrhage, fatty infiltration in the endocardium, and active chronic inflammation, supporting the diagnosis of myocarditis. Several hypotheses of complete heart block in COVID-19 infection have been proposed, including direct myocardial injury and enhanced inflammatory response. A persistent total AV block following complete COVID-19 treatment is an indication for permanent pacemaker implantation.Copyright © 2023, Iranian Heart Association. All rights reserved.

A study of clinical and electrophysiological characteristics of Infrahisian Wenckebach

Objectives: To study the clinico-electrophysiological profile of patients with Infrahisian Wenckebach (IHW) conduction. Material(s) and Method(s): Patients with a clinical diagnosis of atrioventricular (AV) block who underwent permanent pacemaker implantation (PPI) based on standard indications from July 2021-June 2022 at The Madras Medical Mission were subjected to pre-implant Electrophysiology study to document conduction pathology. Result(s): A total of 94 patients underwent PPI for AV block during the study period. EPS was performed in all but one patient (COVID pneumonia). The incidence of IHW was 9/93 (9.6%) of patients with AV block. There is no gender predisposition (M-4, F-5) and their mean age was 71.4 +/- 11.7 years. As many as half of the patients (5/9) had an underlying narrow QRS. The mean QRS duration was 130 +/- 19.3. Ischemic heart disease affected half of the patients and cardiomyopathy in 4/9 patients (mean EF 45.1 +/- 13.7%). Presentation was syncope in all, mean NYHA class was 2.1. Presentation ranged from isolated 1st-degree AV block (1/9) to tri-fascicular block (3/9). In EP study, the mean basal HV interval was 94.7 +/- 27.1 ms. IHW was noted spontaneously in 4 patients and on atrial pacing in the remaining. In the literature, a total of 11 documented cases have been reported (8 case reports). Unlike typical Wenckebach, the increment in PRI is minimal in the 2nd beat of the train. Conclusion(s): Wenckebach periodicity is classically considered an AV nodal phenomenon. IHW is scarcely reported in the literature. Distinction becomes critical as IHW is harbinger of a complete AV block. This is the largest series and the first clinic-etiological profile of IHW patients published to date.

Clinical Outcomes of Patients with COVID-19 Infection and Cardiac Implantable Electronic Devices

BACKGROUND: Existing cardiac disease contributes to poor outcome in patients with coronavirus disease 2019 (COVID-19). Little information exists regarding COVID-19 infection in patients with a cardiac implantable electronic device (CIED). OBJECTIVE(S): To assess the association between CIEDs and severity of COVID-19 infection. METHOD(S): We performed a retrospective analysis including 13,000 patients > 18 years old with COVID-19 infection between January and December 2020. Patients with COVID-19 who had a permanent pacemaker or defibrillator were matched 1:4 based on age and sex followed by univariate and multivariate analyses. Baseline characteristics and clinical outcomes were assessed. RESULT(S): Forty patients with CIED and 160 patients without CIED were included in the current analysis. Mean age was 72.6 +/- 13 years, and approximately 50% were females. Majority of the patients in the study arm had a pacemaker (63%), whereas only 15 patients (37%) had a defibrillator. Patients with COVID-19 and CIED presented more often with atrial fibrillation, coronary artery disease, heart failure, hypertension, diabetes, and chronic kidney disease. They were more likely to be hospitalized in the intensive care unit (ICU) and required more ventilatory support (35% vs. 18.3%). Thirty-day mortality (22.5% vs. 13.8%) and 1-year mortality (25% vs. 15%) were higher among patients with COVID-19 and CIED. CONCLUSION(S): Patients with COVID-19 and CIED had a significantly higher prevalence of co-morbidities that were associated with increased mortality. Although, CIED by itself was not found as an independent risk factor for morbidity and mortality, it may serve as a warning for severe illness with COVID-19.

Primary Cardiac Lymphoma with an Aggressive Hostile Take-Over

Background Primary cardiac lymphoma (PCL) is an extranodal lymphoma involving only the heart and/or pericardium. PCL accounts for 2% of primary cardiac tumors and 0.5% of extranodal lymphomas. Its diagnosis is usually delayed due to rarity and non-specific findings. Case A 77-year-old man with Alzheimer dementia, atrial fibrillation on apixaban, and COVID-19 illness 3-weeks prior, who presented to the hospital with diffuse abdominal discomfort, fatigue, anorexia, and hypoactivity. Patient was tachycardic and normotensive with pronounced jugular venous distention, non-collapsing with respiration. ECG revealed sinus tachycardia, first degree atrioventricular (AV) block and chronic LBBB. Cardiac troponins were mildly elevated without significant delta. An abdominopelvic CT revealed an incidental, large pericardial effusion (PE). Bedside echocardiogram confirmed a large hemodynamically significant PE as well as a mass-like echogenicity encasing and infiltrating the pericardium and myocardium at the basal aspect of the right ventricle free wall. Decision-making In view of recent COVID-19 infection, he was started on indomethacin and colchicine for suspected viral or neoplastic pericarditis. Pericardiocentesis drained 900ml of amber to serosanguineous fluid with quick hemodynamic improvement. Fluid analysis was non-diagnostic for neoplasia. Subsequently, he developed symptomatic bradycardia with an intermittent complete AV block with junctional escape rhythm, transitioning to a second-degree AV block after removal of beta-blocker. Awaiting permanent pacemaker implant, he developed ventricular fibrillation with sudden cardiac death that required prolonged unsuccessful ACLS. Autopsy revealed an extensive infiltrative tumor, predominantly right-sided, consistent with primary cardiac B-cell lymphoma. Conclusion PCL should be part of the working diagnosis in patients presenting with a pericardial effusive process in combination with a right sided myocardial mass. Early cardiac MRI/PET scan or biopsy should be considered when the diagnosis is not certain. Prompt diagnosis could allow for treatment that potentially prolongs survival.Copyright © 2023 American College of Cardiology Foundation

COVID-19 and Complete Heart Block in a Vaccinated Adult

Introduction: Complete heart block (CHB) in association with Covid-19 is uncommon and has been described primarily in the pre-vaccine time period. In the setting of acute Covid-19 infection, decision to treat CHB with permanent pacemaker (PPM) is often uncertain as the CHB may resolve or persist. We present a case of reversible CHB and Covid-19 infection in a vaccinated healthy 28- year-old. Case: A healthy 28-year-old female presented after syncope. She had been vaccinated three times against Covid-19 with Pfizer-BioNTech mRNA vaccine with her third dose four months prior. She had known Covid-19 exposure and developed sore throat three days prior to presenting with syncope. She had no other symptoms. Physical exam was remarkable only for bradycardia. Labs showed positive Covid-19 PCR test and elevated troponin of 0.396 ng/mL. Complete blood counts, metabolic panel, ESR and CRP were normal. Lyme IgM and IgG were negative by Western blot. ECG showed CHB with a rate of 35 beats per minute (Figure 1A). Echocardiogram showed no abnormalities. The patient remained in CHB for 24 hours, at which point PPM was implanted after shared-decision making. Post-PPM ECG showed AV-paced rhythm (Figure 1B). At follow up, PPM interrogation showed that she transitioned to sinus rhythm with right bundle branch block (RBBB) followed by a return to normal sinus rhythm without RBBB 5 days after implantation (Figure 1C). Cardiac MRI two months after PPM implantation showed no abnormalities. Discussion(s): This was a case of Covid-19 associated myocardial injury with CHB in a fullyvaccinated, healthy adult treated with PPM. Despite vaccination, this patient experienced myocardial and conduction system involvement during acute Covid-19 infection. Myocardial injury along with this ECG progression suggested that there was transient inflammation of the myocardial septum resulting in CHB. It may be reasonable to delay PPM implantation in cases of CHB and Covid-19 infection as the CHB may be transient.

A Study Of Clinical And Electrophysiological Characteristics Of Infrahisian Wenckebach

Background: Wenckebach periodicity has classically been considered an AV nodal phenomenon. Infra-Hisian Wenckebach (IHW) scarcely reported in the literature. The distinction, sometimes, becomes critical as IHW is a harbinger of complete AV block and demands permanent pacing contrary to AV nodal Wenckebach. We aimed too study clinico-electrophysiological profile of patients with Infrahisian Wenckebach (IHW) conduction. Method(s): Patients with a clinical diagnosis of atrioventricular (AV) block (excluding complete Heart Block) who underwent permanent pacemaker implantation(PPI) based on standard indications from July 2021-June 2022 at The Madras Medical Mission were prospectively subjected to pre- implant Electrophysiology study to document conduction pathology Results: A total of 94 patients underwent PPI for symptomatic AV block during the study period. EPS was performed in all but one patient (COVID pneumonia). Incidence of IHW was 9/93(9.6%) of patients with AV block. Suprahisian wneckebach was noted in 8/93 patients. There is no gender predisposition (M-4, F-5) and their mean age was 71.4+11.7 years. As many as half of the patients (5/9) had an underlying narrow QRS. The mean QRS duration was 130 + 19.3. Ischemic heart disease affected half of the patients and cardiomyopathy in 4/9 patients (mean EF 45.1+13.7%). Presentation was syncope in all and mean NYHA class was 2.1. Presentation ranged from isolated 1st degree AV block (1/9) to tri-fascicular block (3/9). At EP study, mean basal HV interval was 94.7+27.1ms. IHW was noted spontaneously in 4 patients and on atrial pacing in the remaining. Mean PR interval of the first beat of the Wenckebach cycle was 223 + 14.5 ms. Mean increment in PR interval from the first to the 2nd beat of the cycle was found to be minimal (14.1 + 6.7 ms) which was significantly less when compared to that in patients with suprahisian Wenckebach (44.1 + 10.8 ms), p=0.03). All patients received conduction system pacing implant. In the literature, a total of 11 documented cases have been reports (8 case reports). Ours is the largest case series and first to study the clinical profile of such patients. Conclusion(s): Wenckebach periodicity is classically considered an AV nodal phenomenon. IHW scarcely reported in literature. Distinction becomes critical as IHW is harbinger of complete AV block. However, the prevalence as reported in the current study may not be so less as previously reported, especially with the advent of conduction system pacing where EPS is routinely performed to localize the level of AV block. This is the largest series and first clinic-etiological profile of IHW patients published till date. [Formula presented] Copyright © 2022

CASE SERIES OF SEVERE BRADYCARDIA IN COVID-19 PATIENTS: AN UNUSUAL CARDIAC MANIFESTATION

SESSION TITLE: Cardiovascular Complications in Patients with COVID-19 SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/19/2022 12:45 pm - 1:45 pm INTRODUCTION: Cardiac manifestations of coronavirus disease 2019 (COVID-19) including bradyarrhythmias (BA) are well documented. Postulated mechanisms include direct myocardial injury through viral invasion, myocyte hypoxia, angiotensin-II receptor downregulation, hypercytokinemia and medication-related adverse events. Currently, there are no clear guidelines on the management of severe BA in the setting of COVID-19, including the threshold for permanent pacemaker (PPM) placement. We present a retrospective case series involving five COVID-19 patients with no prior history of cardiovascular disease, who developed severe BA of heart rate < 45 beats per minute. CASE PRESENTATION: Three females and two males were included in the series, with a median age of 50 years (IQR 36-61.5). Sinus bradycardia and high degree heart block were seen in two patients each. Most of the patients were noted to have sinus pauses. Inflammatory markers including D-dimer, LDH, and CRP were elevated. The median CRP in our patients was 106 mg/L (IQR 83.2-208.1) and median D-dimer was 5.63 ug/ml (IQR 1.8-13.2). All patients were treated with dexamethasone and remdesivir. However only one patient was on remdesivir on the day of onset of bradycardia. Four patients were critically ill, requiring ICU care with mechanical ventilation. Two patients required temporary transvenous pacing, one was supported on extracorporeal membrane oxygenation, and one was given atropine. No patient required PPM placement. Two deaths were observed but were not due to BA. DISCUSSION: In this single center, retrospective case series, 5 patients with COVID-19 infection developed severe BA prompting intervention. Laboratory findings demonstrated significantly elevated inflammatory markers in all our patients. The median CRP and D-Dimer in our patients was higher than the median inflammatory markers seen in a systematic review of patients with COVID-19 associated bradycardia showing that the patients in our series were suffering from severe inflammatory state. It was also observed that despite having no prior cardiac history, those more critically ill with COVID-19 infection developed severe BA requiring intervention. Conservative management and reversal of the underlying etiology prevented need for PPM implantation despite two patients developing high-grade atrioventricular-block, and one recurrent asystole. CONCLUSIONS: This preliminary data suggests that even severe BA that develops after COVID-19 infection may not require PPM placement. Further studies are required to elucidate implications, assess the reversibility, and clarify potential therapeutic targets including the indications for PPM in COVID-19 associated bradycardia. Reference #1: Nagamine, Todd et al. "Characteristics of bradyarrhythmia in patients with COVID-19: Systematic scoping review.” Pacing and clinical electrophysiology : PACE, 10.1111/pace.14466. 19 Feb. 2022, doi:10.1111/pace.14466 Reference #2: Chinitz, Jason S et al. "Bradyarrhythmias in patients with COVID-19: Marker of poor prognosis?.” Pacing and clinical electrophysiology : PACE vol. 43,10 (2020): 1199-1204. doi:10.1111/pace.14042 DISCLOSURES: No relevant relationships by Dipanjan Banerjee No relevant relationships by Monika Bernas No relevant relationships by Sandeep Randhawa No relevant relationships by Parthav Shah

Early Single-Center Experience With Meril's Myval Transcatheter Heart Valve

Background: TAVR has emerged as a revolutionary treatment for patients with symptomatic and severe AS, irrespective of surgical-risk profile. Novel transcatheter heart valves (THV) with a lower profile, ease of use and expected longer durability are being developed to target younger and low-risk population. Myval is a 14Fr-balloon expandable THV with a skirt to minimize the occurrence of paravalvular leak (PVL), and has been recently approved for commercial use in Brazil. We sought to report our initial experience with this novel device. Methods: Single-center, single arm, open label prospective registry encompassing all consecutive patients referred to TAVR in our Institution between December 2020 and November 2021. Indication for TAVR was according to current international guidelines. Clinical and echocardiographic outcomes were defined accordingly to VARC-III criteria. Results: A total of 39 patients were enrolled so far. Mean age was 79.5 years, 42% were female and mean STS score was 4%. Pre-procedures mean gradient and aortic valve area were 53.3 mmHg and 0.7cm2, respectively. All procedures were performed under minimalist approach using percutaneous, femoral access. Two patients were treated for bicuspid aortic stenosis and four patients underwent a valve-in-valve procedure. Procedure success was achieved in 100% of the cases, and post-procedure echocardiogram revealed a mean residual gradient of 5 mmHg, with PVL greater than mild in a single case. Permanent pacemaker was required in only 2 patients, and mean hospital stay was 3.1 days. At 30-days, there were two deaths, one due to COVID in a patient who presented major access bleeding requiring prolonged hospital stay, and another one a cardiovascular death. Conclusion: In our initial experience with the Myval THV, valve performance and 30-day clinical results were encouraging. Low rates of complications were observed, comparable to the best last-generation THV. At the time of the meeting, three-month clinical and echocardiographic FU will be available.

Virtual cardiac rehabilitation during the COVID-19 pandemic: a tertiary site experience

Background: The COVID-19 pandemic resulted in the abrupt suspension of centre-based cardiac rehabilitation (CR). Multidisciplinary virtual CR (VCR) with the use of digital, telephone, and video communication was implemented for continued care access. Exercise therapy was delivered through synchronous video-supervised sessions, pre-recorded sessions, and self-directed physical activity. Purpose: To describe patient characteristics, completion rates, and safety outcomes in a real-world VCR population. Methods: Prospective observational study of a tertiary academic CR program. VCR was implemented at pandemic onset (March 2020). Patients who were enrolled in, and either completed or dropped out, during the study period were included. Completers were defined as completing 6 months of virtual enrolment and an exit assessment. Risk was defined by the AACPVR 2020 risk categorization. Adverse cardiovascular events were defined as a patient-initiated event requiring medical assessment and stratified as exercise or non-exercise related. Continuous variables are presented as means and SD or medians and IQR. Student's t-test was used for between group comparisons. Categorical variables are presented as n (%) and compared using the χ2 test or Fischer's exact test. A p-value <0.05 was considered significant. Results: Between March 13th, 2020, and August 31st, 2021, 222 [mean age 61.8 years (SD, 12.6) 77% male], were enrolled and discharged from the VCR program (Table 1). There were 160 completers and 62 non-completers (completion rate 72%). Among the non-completers 26 attended the MD intake assessment only. The remaining 36 completed a median of 85 days (IQR 25-197). This cohort included 21 (9%) high-risk and 35 (16%) moderate risk patients. Those at moderate risk were more likely to be non-completers and those at low risk were more likely to be completers (Table 1). Two exercise and 17 non-exercise adverse events were observed (median clinical surveillance 217 days [IQR 205-240]) (Table 2). Exercise related adverse events included neurally mediated syncope during a synchronous video exercise session in a low risk patient. This was responded to as per centre developed virtual safety protocols. A second syncope related to heart block occurred in a moderate risk patient during independent physical activity and required permanent pacemaker insertion. Both patients completed the program. Three non-exercise adverse cardiac events resulted in cessation of participation included one death and two heart failure hospitalizations (Table 2). One stroke and 13 emergency department visits for cardiac symptoms occurred in completers. Conclusion: Real world VCR is feasible, including in those at moderate to high risk. Modest completion rates and a low exercise related adverse event rate were observed. Synchronous video exercise sessions with video monitoring and safety protocols may improve response to adverse exercise related events. (Table Presented).

A MULTIMODALITY IMAGING DIAGNOSIS OF A CHALLENGING CASE OF CONCOMITANT GROUP 1 PULMONARY HYPERTENSION AND PARADOXICALLY LOW- FLOW, LOW-GRADIENTAORTIC STENOSIS

A 76 year old woman was admitted to our hospital for self-limiting dyspnoea (NYHA class III) in oxygen dependence and frequent lipothymia following Valsalva manoeuvres. She was previously admitted to a Spoke Centre for heart failure (HF) with preserved ejection fraction (EF) and a new diagnosis of “pre-capillary pulmonary hypertension (PH)”. Despite a diagnosis of PH of unclear aetiology, she was started on macitentan without being reassessed for functional capacity due to Covid emergency;because of worsening symptoms, she was admitted to our Hub Centre. Resting ECG showed right axis deviation, right ventricle (RV) hypertrophy, first-degree atrioventricular block and right bundle branch block. Transthoracic echocardiography (TTE) showed reduced left ventricular (LV) volume with preserved EF (diastolic volume= 37 ml, EF=88%), severe right atrial and RV dilation with flattening of the interventricular septum, estimated pulmonary artery systolic pressure (PASP) of 124 mmHg, and moderate calcific aortic stenosis (peak aortic velocity 3.3 m/s, mean gradient 25 mmHg, valve area 1.1 cm2). Right and left heart catheterization showed severe pre-capillary PH (mean pulmonary pressure 60 mmHg, mean wedge 11 mmHg, pulmonary vascular resistance 14.41 WU), a severe aortic valve stenosis (aortic valve area 0.68 cmq and peak-to-peak gradient 25 mmHg, slight reduction of cardiac index 2.04 l/min/mq) and no significant coronary artery disease. The degree of aortic stenosis was considered as moderate-severe by integrating data of transesophageal echocardiography (planimetric area 1cm2) and assessment of calcium score (1615 Agatson units). Pneumological causes, chronic thromboembolic PH, rheumatologic diseases, HIV infection, paraneoplastic origin and veno-occlusive disease were all ruled out as potential PH causes and a diagnosis of Idiopathic pulmonary arterial hypertension (IPAH) was finally made. The Heart Team established the best therapeutic option was a transcatheter aortic valve replacement (TAVI) allowing better haemodynamic tolerability of PH therapy. The patient underwent TAVI and was started on PH therapy;a complete atrio-ventricular block developed after the procedure, requiring permanent pacemaker (PM) implantation. Unfortunately, few days later, the patient died following pacemaker's lead dislocation. Conclusion: PH has a diverse aetiology, and prognosis is generally poor, especially in patients with severe comorbidities. (Figure Presented).

OUTCOMES IN PATIENTS WITH COVID-19 COMPLICATED BY HIGH GRADE ATRIOVENTRICULAR BLOCK

Background: There is growing evidence showing that arrhythmias are one of the major complications of COVID-19.However, there are currently only a few case reports of high-grade atrioventricular block (AVB). We sought to describe a large case series of AVB as a complication of COVID-19. Objective: The purpose of the current study is to describe a large case series of AVB as a complication of COVID-19. Methods: We included a series of twenty-five (25)consecutive patients with confirmed COVID-19, who developed advanced AVB in a prospective observational multi-center study. Patients underwent clinical, laboratory evaluation, Holter, telemetry, Echocardiogram, Chest X-Ray, chest CT scan and cardiac MRI Results: Of the 25 patients 13 were male with a mean age of 62+-13 years. 19 developed complete AVB, one a 3:1 AVB and five 2:1 AVB. None of the patients had a history of cardiac arrhythmia. AVB was not related to medication or intubation. Eighteen patients developed AVB during their hospitalization for COVID-19 and 7 after the first month as a late sequela. Five patients were asymptomatic, 6 presented syncope, seven dyspnea and seven dizziness. Eleven patients presented reverse AVB early by a high dose of corticosteroid in all of them, and combined with colchicine in 4 cases, with no recurrent episodes. 13 patients required a permanent pacemaker for persistent conduction defect (52%) and one died of ventricular fibrillation without pacemaker Conclusion: Advanced AVB could be a complication of COVID-19. The conduction disturbance was reversed by corticosteroids with or without colchicine in eleven of twenty five cases (44%)The resolution with corticosteroids of the advanced AVB in these patients could reflect the transient nature of the viral infection and the inflammatory response associated with it in some patients. 13 patients required a pacemaker(52%). Physicians should be aware of this complication.

ASYSTOLE WITH REMDESIVIR IN A PATIENT WITH LIMB-GIRDLE MUSCULAR DYSTROPHY

Background: Remdesivir has been recognized as an antiviral in the treatment arsenal of hospitalized patients with COVID-19;however, it is associated with sinus node dysfunction - a finding that is not completely understood. Objective: To highlight possible side effects of remdesivir and its association with cardiac conduction abnormalities. Methods: n/a Results: A 79-year-old woman with limb-girdle muscular dystrophy (LGMD) presented to the emergency department with worsening dyspnea and heart palpitation with no recent syncopal events. The patient was found to be COVID-19 positive despite being fully vaccinated months prior. On admission, her ECG (Panel A) demonstrated atrial flutter with 2:1 conduction and a LBBB. Given her symptomatic hypotension, she was successfully cardioverted to sinus rhythm then followed with sinus bradycardia. Given her COVID-19 infection, she was started on dexamethasone and remdesivir. Her overnight course was complicated by a transiently profound nocturnal sinus bradycardia leading to asystolic arrest for up to 15 seconds (Panel B). Her profound bradycardia was then thought to be precipitated by hypersomnolence in the presence of underlying sinus node dysfunction, unmasked by the combination of steroids and remdesivir. Patient continued to have similar pauses during her second night despite the use of non-invasive positive pressure ventilation and Isuprel drip. At that point, the decision was made to discontinue remdesivir with complete resolution of her profound bradycardic events. Isuprel was subsequently discontinued with no recurrence of her symptomatic bradycardia. The patient was monitored successfully for three days with no electrocardiac disturbances. Conclusion: Although LGMD is associated with conduction abnormalities, it can be profoundly unmasked with remdesivir. Sinus node dysfunction may improve with discontinuation of remdesivir. Therefore, it is important to allow for monitoring of patients on remdesivir experiencing symptomatic profound bradycardia before the commitment to a permanent pacemaker. [Formula presented]

GRAVE DANGER: RARE CASE OF COMPLETE HEART BLOCK SECONDARY TO GRAVES DISEASE

Background: Complete heart block (CHB) is a cardiac conduction disorder commonly due to age-related degeneration of the conduction system. Other etiologies include hypothyroidism, Lyme disease or COVID-19, infiltrative cardiomyopathy, myocarditis, and atrioventricular (AV) nodal blocking agents. Hyperthyroidism is an extremely rare cause of CHB. Case: We present the case of a 40-year-old previously healthy male who presented after two syncopal episodes. He denied any home medications, recreational drug use, or prior syncopal episodes. He did endorse worsening palpitations, heat intolerance, anxiety, insomnia and diarrhea for one month. Initial EKG was normal. Labs revealed an undetectable thyroid stimulating hormone (TSH), and high T4 of 3.26 ng/dL. Potassium was 3.1 mMol/L which was replaced to normal levels. In the emergency department, he had another syncopal episode. Telemetry showed a 20 second episode of CHB. Patient was admitted and started on methimazole. Decision-making: Labs showed positive TSH receptor antibodies and thyroid stimulating immunoglobulins, confirming a diagnosis of Graves’ disease. COVID-19 IgG antibodies were positive with negative COVID-19 PCR, indicative of remote COVID 19 infection. Cardiac MRI did not show any myocarditis or infiltrative disease, and otherwise revealed a structurally normal heart. Lyme disease antibodies were negative. Toxicology screen was negative. Thyroid ultrasound showed diffuse heterogeneity of the gland. 72 hour telemetry monitoring revealed no further conduction abnormalities. At this point, CHB wes attributed to hyperthyroidism. As this was reversible, and CHB resolved after initiation of methimazole, a permanent pacemaker was not placed. He was discharged with a 30-day event monitor which did not show any conduction abnormalities. Conclusion: This case highlights a rare sequela of hyperthyroidism induced CHB. Although the pathophysiology is not well understood, a proposed mechanism is the direct toxic effect of T3 leading to focal inflammation of the AV node. Further studies are needed to evaluate the pathophysiology and chronicity of this process, which will assist in the decision to implant a permanent pacemaker.

Early Single-Center Experience With Meril's Myval Transcatheter Heart Valve

Background: TAVR has emerged as a revolutionary treatment for patients with symptomatic and severe AS, irrespective of surgical-risk profile. Novel transcatheter heart valves (THV) with a lower profile, ease of use and expected longer durability are being developed to target younger and low-risk population. Myval is a 14Fr-balloon expandable THV with a skirt to minimize the occurrence of paravalvular leak (PVL), and has been recently approved for commercial use in Brazil. We sought to report our initial experience with this novel device. Methods: Single-center, single arm, open label prospective registry encompassing all consecutive patients referred to TAVR in our Institution between December 2020 and November 2021. Indication for TAVR was according to current international guidelines. Clinical and echocardiographic outcomes were defined accordingly to VARC-III criteria. Results: A total of 39 patients were enrolled so far. Mean age was 79.5 years, 42% were female and mean STS score was 4%. Pre-procedures mean gradient and aortic valve area were 53.3 mmHg and 0.7cm2, respectively. All procedures were performed under minimalist approach using percutaneous, femoral access. Two patients were treated for bicuspid aortic stenosis and four patients underwent a valve-in-valve procedure. Procedure success was achieved in 100% of the cases, and post-procedure echocardiogram revealed a mean residual gradient of 5 mmHg, with PVL greater than mild in a single case. Permanent pacemaker was required in only 2 patients, and mean hospital stay was 3.1 days. At 30-days, there were two deaths, one due to COVID in a patient who presented major access bleeding requiring prolonged hospital stay, and another one a cardiovascular death. Conclusion: In our initial experience with the Myval THV, valve performance and 30-day clinical results were encouraging. Low rates of complications were observed, comparable to the best last-generation THV. At the time of the meeting, three-month clinical and echocardiographic FU will be available.

The Tasmanian TAVI Service: Initial Experience and Outcomes

Background: Transcatheter aortic valve implantation (TAVI) is now guideline treatment for severe aortic stenosis in patients over the age of 80 years. Objective: We report the initial experience of the first 50 patients for the Tasmanian TAVI Service at the Royal Hobart Hospital established during the COVID-19 pandemic. Methods: The records of patients undergoing TAVI with a balloon-expandable device between June 2020 and March 2021 at the Royal Hobart Hospital were reviewed. We report the procedural success and outcome, including major adverse events and haemodynamic results at the 30-day follow-up. Results: Mean age was 83.2±0.7 and mean EuroSCORE II and Society of Thoracic Surgeons’ scores were 5.6%±0.4% and 6.2%±1.0%, respectively;18% had undergone prior cardiac surgery. Successful transfemoral deployment of the valve was achieved in all patients. The cumulative stroke and mortality rates at 30 days were 0%. The minor vascular complication rate was 3.8%, with no major vascular complications, as per the Valve Academic Research Consortium-2 (VARC-2) criteria. No/trivial paravalvular aortic regurgitation (pAR) was observed in 79%, with 21% mild pAR. The mean AVA (cm2) increased from 0.73 to 2.1, with a subsequent mean reduction in mean gradient (mmHg) from 40 to 10. Post-TAVI permanent pacemaker rate was 12%. Median length of hospital stay was 1.48 days. Conclusion: TAVI is now readily accessible locally for Tasmanians deemed suitable for intervention as per the state-wide heart team. Early results are excellent and indicate that TAVI is being used appropriately, according to current national and international guidelines.

Emergent temporary transvenous pacemakers were infrequently needed for patients presenting with complete heart block at a regional hospital

Introduction: Patients presenting with Complete heart block (CHB) are emergently referred for placement of a temporary transvenous pacemaker (TTVP) for hemodynamic stability. Data on the immediate management and outcomes of such patients are lacking. Methods: Data collected;through retrospective chart review of patients presenting to the Emergency Department (ED) at a regional hospital from October 2017 to January 2021 with a diagnosis of new CHB;included age, sex, clinical, laboratory and ECG data, medications, interventions and length of stay. Results: There were 71 patients (31 women) of whom 19 were on beta blocker or Calcium channel blockers. Data (see Table 1) for all variables was available in 68 patients. Syncope, lightheadedness and dyspnea were common symptoms. The median age was 77 years. The median heart rate was 41bpm. Atropine was used in 13 patients. Five patients with initial Systolic Blood Pressure (SBP) < 100mmHg received sympathomimetics. Syncope with pause occurred in 3 patients. A TTVP was placed in 12 patients. Among 22 patients with initial SBP > 160mmHg one patient with a recent TAVR had a TTVP placed. All but five were managed in the ICU setting. On Univariate logistic regression (R statistical software 3.6.1) initial SBP, SBP < 100mmHg and Initial Serum K level were clinically significant. In multivariate analysis, SBP was significant with a lower SBP predicting need for a TTVP [OR 0.96 (CI 0.91-0.99, p = 0.019)]. A permanent pacemaker (PPM) prior to discharge was placed in 64 patients on average in 1.6 days from presentation. 3 patients with STEMI and TTVP did not need a PPM. 1 transitioned to hospice and 1 patient died of sepsis. In 1 it was attributed to COVID-19 infection. Conclusions: TTVP was infrequently needed (16.66%) among patients presenting to the ED with CHB. Initial SBP and Serum K were clinically relevant factors. Prospective data related to the acute management of CHB is needed to identify predictors that can improve the care for such patients.

Advanced atrio-ventricular block in patients with active covid-19 infection

Introduction: Cardiac arrhythmia is a frequent complication of COVID-19, However, there are currently only a few case reports of advanced atrioventricular block (AVB). Hypothesis: We sought to describe a case series of AVB as a complication of COVID-19. Methods: We included a series of ten (10) consecutive patients with confirmed COVID-19, who developed advanced AVB in a prospective observational multi-center study. Patients underwent clinical, laboratory evaluation, Holter, telemetry, Echocardiogram, Chest X-Ray, chest CT scan and cardiac MRI. Results: Of the ten (10) patients, 5 were female (50%) with a mean age of 62,7 +-11,5 years. Eight (8) developed complete AVB, one a 3:1 AVB and one 2:1 AVB. None of the patients had a history of cardiac arrhythmia AVB was not related to medication or intubation. Six patients developed AVB during their hospitalization for COVID-19 and 4 after the first month as a late sequela. Four patients were asymptomatic, one presented syncope, two dyspnea and two dizziness. Six patients presented reverse AVB early by a high dose of corticosteroid in six and colchicine in 3 cases, with no recurrent episodes.Four patients required a permanent pacemaker for persistent conduction defect. Conclusions: Advanced AVB could be a complication of COVID-19. The conduction disturbance was reversed by corticosteroids with or without colchicine in six of ten cases The resolution with corticosteroids of the advanced AVB in these patients could reflect the transient nature of the viral infection and the inflammatory response associated with it in some patients. Four patients required a pacemaker. Physicians should be aware of this complication.

COVID-19 and Cardiac Arrhythmias

Coronavirus disease-2019 (COVID-19) has impacted the global population, leading to a pandemic, the scale of which the world has never experienced before. This novel coronavirus not only involves the respiratory system, but also affects the heart, leading to significant morbidity and mortality. Arrhythmias in COVID-19 are increasingly being documented and seem to have a prognostic significance, especially in critically ill patients. In patients with COVID-19, a variety of arrhythmias have been reported, ranging from the benign to potentially life-threatening. Multiple mechanisms, such as myocarditis, hypoxia, electrolyte disturbances and QT interval-prolonging drugs (e.g. hydroxychloroquine), are responsible for arrhythmias in patients with COVID-19. The prevalence of cardiac arrhythmias in patients with COVID-19 ranges from 3.6% to 60%, with sinus tachycardia being the most common rhythm abnormality. Other rhythm abnormalities, such as sinus bradycardia, atrial arrhythmias and complete heart block, have also been reported. Malignant ventricular arrhythmias, especially in patients with COVID-19 with multiple comorbidities, portend a bad prognosis. Additionally, the use of QT interval-prolonging drugs, such as hydroxychloroquine or azithromycin, increases the risk of torsades de pointes. Hence, there is a need for continuous rhythm monitoring, with prompt recognition of arrhythmias in critically ill patients and those on QT-prolonging medications. Management of these arrhythmias is similar to those in patients without COVID-19, with a focus on correcting reversible causes and maintaining haemodynamic stability.