Episodes Of Nonsustained Ventricular Tachycardia Research Articles

Impaired myocardial energetics in both sarcomere positive and negative HCM are linked to arrhythmic risk

Abstract Background Impaired myocardial energetics play a pivotal role in the complex pathophysiology of hypertrophic cardiomyopathy (HCM), and are thought to be mediated by energy-costly sarcomeric mutations and mitochondrial dysfunction (1). Two thirds of HCM patients, however, do not possess pathogenic sarcomeric mutations (2) and instead develop the condition due to a combination of increased polygenic susceptibility and comorbidities. Whether energetic impairment, a target of novel HCM treatments (e.g., myosin modulators such as Mavacamten), similarly affects sarcomere mutation positive (Sarc+) and negative (Sarc-) HCM remains unclear, as does the association between impaired energetics and markers of arrhythmic risk such as hypertrophy severity, cardiac function and non-sustained ventricular tachycardia (NSVT). This study aimed to investigate differences in resting myocardial energetics between Sarc+ and Sarc- HCM by measuring the phosphocreatine-to-adenosine triphosphate (PCr/ATP) ratio using phosphorus magnetic resonance spectroscopy (31P-MRS) and explore the association between impaired energetics and markers of arrhythmic risk in HCM. Methods We recruited one hundred (100) participants (80 non-obstructive HCM patients and 20 age- and sex-matched controls). Myocardial energetics were assessed using 31P-MRS to measure the PCr/ATP ratio. Cardiac magnetic resonance (CMR) imaging including cine, T1 (ShMOLLI), quantitative pixel-wise perfusion mapping (3) and late gadolinium enhancement (LGE) imaging was also performed. In addition, HCM patients underwent 7-day ECG monitoring to document NSVT episodes (3 beats ≥120 bpm). Results HCM patients had impaired myocardial energetics (PCr/ATP ratio) relative to controls (HCM 1.64±0.36 vs controls 1.97±0.32 p<0.001). PCr/ATP ratios did not differ between Sarc+ and Sarc- HCM even after adjustment for confounders including age, hypertrophy and fibrosis burden (Sarc+ 1.64 [1.50-1.78] vs Sarc- 1.64 [1.52-1.77], p=0.993). PCr/ATP ratio showed no correlation with maximum wall thickness (p=0.257), left ventricular ejection fraction (p=0.727) or myocardial perfusion reserve (p=0.851), but did inversely correlate with global longitudinal strain (r=-0.3, p=0.025). Reduced PCr/ATP was associated with presence of fibrosis (LGE+ 1.58±0.35 vs LGE- 1.79±0.37 p=0.025) and with NSVT, independent of age or fibrosis burden (NSVT+ 1.54 [1.40-1.67] vs NSVT- 1.73 [1.62-1.86], p=0.046). Conclusion Myocardial energetics are similarly impaired in Sarc+ and Sarc- HCM, and are independently associated with impaired contractility, greater fibrosis severity and heightened arrhythmic risk. Our findings provide novel mechanistic insights into the potentially favourable response of HCM patients to energy-sparing myosin modulator therapies irrespective of genotype and highlight the potential for cardiac energetics to serve as a marker of arrhythmic risk.

Amiodarone or Implantable Cardioverter-Defibrillator in Chagas Cardiomyopathy

Over 10 000 people with Chagas disease experience sudden cardiac death (SCD) annually, mostly caused by ventricular fibrillation. Amiodarone hydrochloride and the implantable cardioverter-defibrillator (ICD) have been empirically used to prevent SCD in patients with chronic Chagas cardiomyopathy. To test the hypothesis that ICD is more effective than amiodarone therapy for primary prevention of all-cause mortality in patients with chronic Chagas cardiomyopathy and moderate to high mortality risk, assessed by the Rassi score. CHAGASICS is an open-label, randomized clinical trial. The study enrolled patients from 13 centers in Brazil from May 30, 2014, to August 13, 2021, with the last follow-up November 8, 2021. Patients with serological findings positive for Chagas disease, a Rassi risk score of at least 10 points (intermediate to high risk), and at least 1 episode of nonsustained ventricular tachycardia were eligible to participate. Data were analyzed from May 3, 2022, to June 16, 2023. Patients were randomized 1:1 to receive ICD or amiodarone (with a loading dose of 600 mg after randomization). The primary outcome was all-cause mortality, and secondary outcomes included SCD, hospitalization for heart failure, and necessity of a pacemaker during the entire follow-up. The study was stopped prematurely for administrative reasons, with 323 patients randomized (166 in the amiodarone group and 157 in the ICD group), rather than the intended 1100 patients. Analysis was by intention to treat at a median follow-up of 3.6 (IQR, 1.8-4.4) years. Mean (SD) age was 57.4 (9.8) years, 185 patients (57.3%) were male, and the mean (SD) left ventricular ejection fraction was 37.0% (11.6%). There were 60 deaths (38.2%) in the ICD arm and 64 (38.6%) in the amiodarone group (hazard ratio [HR], 0.86 [95% CI, 0.60-1.22]; P = .40). The rates of SCD (6 [3.8%] vs 23 [13.9%]; HR, 0.25 [95% CI, 0.10-0.61]; P = .001), bradycardia requiring pacing (3 [1.9%] vs 27 [16.3%]; HR, 0.10 [95% CI, 0.03-0.34]; P < .001), and heart failure hospitalization (14 [8.9%] vs 28 [16.9%]; HR, 0.46 [95% CI, 0.24-0.87]; P = .01) were lower in the ICD group compared with the amiodarone arm. In patients with chronic Chagas cardiomyopathy at moderate to high risk of mortality, ICD did not reduce the risk of all-cause mortality. However, ICD significantly reduced the risk of SCD, pacing need, and heart failure hospitalization compared with amiodarone therapy. Further studies are warranted to confirm the evidence generated by this trial. ClinicalTrials.gov Identifier: NCT01722942.

Extended Ambulatory ECG Monitoring Enhances Identification of Higher-Risk Ventricular Tachyarrhythmias in Patients With Hypertrophic Cardiomyopathy

BackgroundIn hypertrophic cardiomyopathy (HCM), 48-hour ambulatory monitoring has been standard practice to detect nonsustained ventricular tachycardia (NSVT), a sudden death risk marker. Extended-wear ambulatory electrocardiographic (ECG) devices have more recently used for monitoring patients with HCM. ObjectiveWe aimed to evaluate NSVT burden identified with continuous ambulatory monitoring for up to 2 weeks compared with initial 48 hours. MethodsThere were 236 consecutive patients with HCM (49 ± 12 years) who underwent 14-day continuous ambulatory monitoring (Zio XT, iRhythm Technologies, San Francisco, CA); diagnostic yield of NSVT compared for initial 48 hours vs extended for 14 days. ResultsOf 236 patients, 114 (48%) had ≥ 1 runs of NSVT (median 2) over 14 days. Median length of NSVT was 7 beats (range: 3 to 67) at rates of 120 to 240 beats per minute (bpm) (median, 167 bpm). In 42 of the 114 patients (37%), initial NSVT occurred ≤ 48 hours and in 72 (63%) only during the extended monitoring period (3 to 14 days). Diagnostic yield for detecting NSVT over 14 days was 2.7-fold greater than ≤ 48 hours (P < .001). NSVT judged at higher risk (≥ 8 beats, > 200 bpm, ≥ 2 runs in consecutive 2-day period) was identified more frequently during extended monitoring, diagnostic yield 3-fold greater than ≤ 48 hours (P < .001). ConclusionIn HCM, NSVT episodes are frequent; however, in most patients, both NSVT and higher-risk NSVT were not detected during initial 48 hours and were confined solely to extended monitoring period. These data support additional clinical studies to evaluate the significance of NSVT on extended monitoring on sudden death risk in HCM.

Prevalence of frequent premature ventricular contractions and nonsustained ventricular tachycardia in older women screened for atrial fibrillation in the Women’s Health Initiative

BackgroundFrequent premature ventricular contractions (PVCs) and nonsustained ventricular tachycardia (NSVT) have been associated with cardiovascular disease and mortality. Their prevalence, especially in ambulatory populations, is understudied and limited by few female participants and the use of short-duration (24- to 48-hour) monitoring. ObjectiveThe objective of this study was to report the prevalence of frequent PVCs and NSVT in a community-based population of women likely to undergo electrocardiogram (ECG) screening by sequential patch monitoring. MethodsParticipants from the Women’s Health Initiative Strong and Healthy (WHISH) trial with no history of atrial fibrillation (AF) but 5-year predicted risk of incident AF ≥5% by CHARGE-AF score were randomly selected to undergo screening with 7-day ECG patch monitors at baseline, 6 months, and 12 months. Recordings were reviewed for PVCs and NSVT (>5 beats); data were analyzed with multivariate regression models. ResultsThere were 1067 participants who underwent ECG screening at baseline, 866 at 6 months, and 777 at 12 months. Frequent PVCs were found on at least 1 patch from 4.3% of participants, and 1 or more episodes of NSVT were found in 12 (1.1%) women. PVC frequency directly correlated with CHARGE-AF score and NSVT on any patch. Detection of frequent PVCs increased with sequential monitoring. ConclusionIn postmenopausal women at high risk for AF, frequent PVCs were relatively common (4.3%) and correlated with higher CHARGE-AF score. As strategies for AF screening continue to evolve, particularly in those individuals at high risk of AF, the prevalence of incidental ventricular arrhythmias is an important benchmark to guide clinical decision-making.

Implantable loop recorder monitoring in inherited cardiomyopathies: yield of clinically relevant arrhythmias

Abstract Background Implantable loop recorders (ILRs) are a minimally invasive tool for the diagnosis of arrhythmias in patients with unexplained syncope or asymptomatic arrhythmias. Their use in patients with inherited arrhythmia syndromes has been recommended in the recent 2022 ESC Guidelines (1). However, the clinical utility of ILRs in patients with inherited cardiomyopathies remains unexplored. Purpose The purpose of this study was to evaluate the yield of ILR monitoring in detecting clinically relevant events in a single cohort of patients with inherited cardiomyopathies. Methods We prospectively collected demographic, clinical, and follow-up data from patients with inherited cardiomyopathies (Arrhythmogenic Cardiomyopathy, ACM; Hypertrophic Cardiomyopathy, HCM; Dilated Cardiomyopathy, DCM; Left Ventricular Non-Compaction, LVNC) who were implanted with an ILR and were followed with telemedicine. The primary endpoint was a clinically significant event recorded with the ILR that required an update to an implantable cardioverter defibrillator (ICD). Results The study cohort included 53 consecutive patients (55% males; mean age at ILR implantation 35±14 years) with inherited cardiomyopathies: 33/53 (62%) with ACM, 9/53 (17%) with HCM, 7/53 (13%) LVNC, 4/33 (8%) DCM. None of the patients implanted had previously experienced life-threatening arrhythmias. During a median follow-up of 2.6 years (IQR 1.4-3.7 years) after ILR implantation, clinically relevant arrhythmic events were documented in 9/53 (17%) of patients. Specifically, sustained or non-sustained ventricular tachycardia episodes were detected in 8 patients (5 with ACM, 2 with LVNC, 1 with LMNA-related DCM), whereas one patient with HCM showed symptomatic pauses &amp;gt; 3 seconds due to sick sinus syndrome. In all cases, the detection of such episodes led to the upgrade to ICD implantation. Conclusions ILR monitoring of patients with inherited cardiomyopathies identified clinically relevant events in almost one-fifth of patients, suggesting that the use of ILR may substantially improve the management of these patients. Figure 1. Representative example of clinically actionable event detected by implantable loop recorder (ILR) in a patient with inherited cardiomyopathy. The patient, a 19-year-old male with a definitive diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) and a pathogenic PKP2 truncating variant, presented with palpitations and vertigo during physical exertion one year after the implantation of an ILR. ILR monitoring documented a rapid tachycardia with a mean frequency of 250 bpm lasting 3 minutes, prompting an indication for an implantable cardioverter defibrillator (ICD).Figure 1.

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 18687: Cardio-Rheumatology: Coronary and Cerebrovascular Thromboses in Antiphospholipid Antibody Syndrome

Description of Case: A 27-year-old male with antiphospholipid antibody syndrome (APLS) with a high-risk antibody profile presented for cardiac evaluation. APLS was diagnosed after presentation with acute cardioembolic stroke requiring thrombolysis. Echocardiography showed a normal ejection fraction, with multiple small echo-densities attached to the anterior and posterior leaflet tips of the mitral valve suggesting non-bacterial thrombotic endocarditis (NBTE). The patient was treated with warfarin and aspirin was recommended but declined. As the patient reported lightheadedness, a cardiac rhythm monitor was placed and showed two episodes of non-sustained ventricular tachycardia (NSVT). A cardiac MRI was then obtained, showing multifocal, subendocardial and mesocardial delayed gadolinium enhancement suggesting fibrosis, in a distribution most consistent with a multivessel embolic event. A CT coronary angiogram was performed to further evaluate the coronary arteries, revealing normal coronary anatomy, free from atherosclerotic plaque or thrombus. Beta-blocker therapy was initiated for arrhythmic episodes, with resolution of symptoms and no recurrence of NSVT on follow-up monitoring. Left ventricular (LV) function continued to remain preserved on follow-up imaging, with no progression of mitral valve vegetations on anticoagulation. Discussion: Cardiac involvement in APLS has been well described but largely centers around valvular disease and de novo venous and arterial thromboses. This case of cerebrovascular and coronary pathology in APLS as a likely consequence of thromboembolic phenomena is an unusual presentation and highlights the potential downstream consequences of left-sided valvular NBTE. A high index of suspicion is required to specifically evaluate for myocardial scarring despite normal LV function on echocardiography. The presence of myocardial fibrosis in these cases can act as a focus for scar-related ventricular arrhythmias, which if diagnosed and treated in a timely manner can limit further cardiovascular complications for the patient.

T-Wave Oversensing with Contemporary Implantable Cardioverter-Defibrillators.

Implantable cardioverter-defibrillators (ICDs) need to reliably detect ventricular tachycardia (VT) and ventricular fibrillation (VF) while avoiding T-wave oversensing (TWOS), which is associated with a risk of inappropriate therapies. The incidence of TWOS with endovascular ICDs appears to differ between manufacturers. We aimed to evaluate the incidence and clinical consequences of TWOS with contemporary Medtronic and Boston Scientific ICDs. Consecutive patients implanted with a recent Medtronic or Boston Scientific ICD and remotely monitored at three French centers were included. All transmitted EGMs labelled as VF, VT, non-sustained VT (NSVT), or ventricular oversensing (Medtronic) were screened for TWOS. Among 7589 transmitted episodes from 674 patients with a Boston Scientific ICD, we did not identify a single case of TWOS. Among 16,790 transmitted episodes from 1733 patients with a Medtronic ICD, we identified 60 patients (3.4%) with at least one episode of TWOS. In 46 patients, TWOS was intermittent (NSVT episodes). In the remaining 14 patients, TWOS resulted in 60 sustained episodes (completed counters). No inappropriate therapies were delivered in 12 of these patients because no therapies were programmed (in monitor zones, 11 episodes) or because therapies were inhibited by the morphology discriminator (Wavelet, 19 episodes) or by the anti-TWOS algorithm (26 episodes). Two patients received inappropriate therapies due to TWOS (0.1% of patients with Medtronic ICDs). On review of 24,379 transmitted episodes from 2407 patients with endovascular ICDs, we found no case of TWOS with Boston Scientific devices, whereas TWOS was not uncommon with Medtronic devices. However, the risk of inappropriate therapy with Medtronic ICDs was very low (0.1%) due to the often intermittent nature of this phenomenon, the morphology discriminator, and the anti-TWOS algorithm.

Subclinical Left Ventricular Dysfunction and Ventricular Arrhythmias in Older Adults With Normal Ejection Fraction.

Background Premature ventricular contractions (PVCs) and nonsustained ventricular tachycardia (NSVT) are known to be associated with reduced left ventricular (LV) ejection fraction and adverse outcomes in patients with structural heart disease. The relationship between subclinical LV dysfunction and ventricular arrhythmias in the general population is not established. Methods and Results Participants in the SAFARIS (Subclinical Atrial Fibrillation and Risk of Ischemic Stroke) study with normal left ventricular ejection fraction (n=503; mean age 77 years, 63% women) underwent 14-day electrocardiographic monitoring and 2-dimensional echocardiography. Frequent PVCs were defined as PVCs >500 per 24 hours and NSVT as ≥4 consecutive ventricular ectopic beats. Reduced LV global longitudinal strain (GLS) was used as an indicator of subclinical LV dysfunction. Seventy-six participants (15.1%) had PVCs >500/d, 117 (23.3%) had NSVT episodes. LV GLS was significantly reduced in both frequent PVCs and NSVT groups (P<0.01). In multivariable analyses, lower LV GLS was associated with frequent PVCs (adjusted odds ratio [aOR], 1.19 [95% CI, 1.09-1.30 per unit reduction]; P<0.001) and NSVT (aOR, 1.09 [95% CI, 1.01-1.17]; P=0.036) independently of established risk factors and other echocardiographic parameters. Abnormal LV GLS (>-15.8%) carried a 2-fold increase in risk of ventricular arrhythmias (aOR, 2.18, P=0.029 for PVCs; aOR, 2.09, P=0.026 for NSVT). Conclusions PVCs and NSVT episodes were frequent in this community-based elderly cohort with normal left ventricular ejection fraction and were independently associated with lower LV GLS. The association between LV dysfunction and ventricular arrhythmias is present at an early, subclinical stage, an observation that carries possible preventative implications.

Artificial intelligence for detection of ventricular oversensing: Machine learning approaches for noise detection within nonsustained ventricular tachycardia episodes remotely transmitted by pacemakers and implantable cardioverter-defibrillators

Pacemakers (PMs) and implantable cardioverter-defibrillators (ICDs) increasingly automatically record and remotely transmit nonsustained ventricular tachycardia (NSVT) episodes, which may reveal ventricular oversensing. We aimed to develop and validate a machine learning algorithm that accurately classifies NSVT episodes transmitted by PMs and ICDs in order to lighten health care workload burden and improve patient safety. PMs or ICDs (Boston Scientific) from 4 French hospitals with ≥1 transmitted NSVT episode were split into 3 subgroups: training set, validation set, and test set. Each NSVT episode was labeled as either physiological or nonphysiological. Four machine learning algorithms-2DTF-CNN, 2D-DenseNet, 2DTF-VGG, and 1D-AgResNet-were developed using training and validation data sets. Accuracies of the classifiers were compared with an analysis of the remote monitoring team of the Bordeaux University Hospital using F2 scores (favoring sensitivity over predictive positive value) using an independent test set. A total of 807 devices transmitted 10.471 NSVT recordings (82% ICD; 18% PM), of which 87 devices (10.8%) transmitted 544 NSVT recordings with nonphysiological signals. The classification by the remote monitoring team resulted in an F2 score of 0,932 (sensitivity 95%; specificity 99%) The 4 machine learning algorithms showed high and comparable F2 scores (2DTF-CNN: 0,914; 2D-DenseNet: 0,906; 2DTF-VGG: 0,863; 1D-AgResNet: 0,791), and only 1D-AgResNet had significantly different labeling from that of the remote monitoring team. Machine learning algorithms were accurate in detecting nonphysiological signals within electrograms transmitted by PMs and ICDs. An artificial intelligence approach may render remote monitoring less resourceful and improve patient safety.

Multimodality Imaging-Based Therapeutic Decision in Ischemic Cardiomyopathy and Ventricular Tachycardia – a Case Report

Abstract Introduction In patients with ischemic heart disease and coronary chronic total occlusion, it is extremely important to assess the presence of myocardial viability via different cardiac imaging techniques in order to predict a potential functional recovery following revascularization. Multimodality cardiac imaging techniques estimate the risk of sudden cardiac death and personalize patient selection for primary prevention implantable cardioverterdefibrillator therapy. Case presentation A 61-year-old patient with a history of an extensive anterior myocardial infarction with conservative management (8 years before the current presentation, when the coronary angiography revealed two-vessel chronic total occlusion) presented to our outpatient service for fast-paced palpitations at home and fatigue. At the time of the index hospitalization, the patient refused coronary artery bypass grafting. During this period, he did not undergo any cardiovascular evaluation, but he did follow the pharmacological recommendations from the initial hospital discharge. Given the detection of multiple premature ventricular contractions and numerous episodes of nonsustained ventricular tachycardia during this medical visit, a multimodal imaging evaluation was conducted, which further guided the implementation of a personalized therapy. Conclusions In patients with ischemic heart failure and coronary chronic total occlusion, presenting with ventricular tachycardia, the therapeutic decision should be based on the results of a multi-modality cardiac imaging evaluation.

The impact of mitral valve surgery on ventricular arrhythmias in patients with Barlow's disease: preliminary results of a prospective study.

Aim of this study was to evaluate arrhythmic burden of patients with Barlow's disease and significant mitral regurgitation (MR) and assess the impact of mitral repair on ventricular arrhythmias (VA) in this group of subjects. We prospectively included 88 consecutive patients with Barlow's disease referred to our Institution from February 2021 to May 2022. All enrolled patients underwent 24-h Holter monitoring before surgery. Sixty-three of them completed 3 months echocardiographic and Holter follow-up. Significant arrhythmic burden was defined as ≥1% premature ventricular beats/24 h or at least one episode of non-sustained ventricular tachycardia (VT), VT or ventricular fibrillation. At baseline, 29 patients (33%) were arrhythmogenic (AR), while 59 (67%) were not [non-arrhythmogenic (NAR)]. AR subjects tended to be more often females with history of palpitations. Sixty-three patients completed 3-months follow-up. Twenty of them (31.7%) were AR at baseline and 43 (68.3%) were not. Among AR patients, 9 (45%) remained AR after mitral surgery, while 11 (55%) became NAR. Considering NAR subjects at baseline, after mitral valve repair 8 (18.6%) evolved into AR, while 35 (81.4%) remained NAR. A higher prevalence of pre-operative MAD was found among patients experiencing VA reduction if compared with patients who remained arrhythmogenic (63.6% vs 11.1%, P = 0.028). In our experience, one-third of Barlow's patients referred for mitral surgery showed a significant arrhythmic burden. Almost half of the subjects arrhythmogenic at baseline were free from significant VA after mitral repair. However, a minority (18.6%) of subjects without arrhythmic burden at baseline experienced significant VA at follow-up.

Telemonitoring heart failure in a remote region: data from cardiac implantable electronic devices

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Heart failure (HF) represents an important burden to the medical system attending to its high prevalence and high risk of hospital admissions by decompensations. Remote monitoring (RM) systems using invasive and non-invasive parameters were developed to anticipate clinical deterioration in patients with cardiac implantable electronic devices (CIEDs). Objective To characterize a cohort of patients with HF and CIEDs in an outermost region. We aimed to accessed data from monitoring device algorithms and to analyze the real impact in clinical decompensations, hospital admissions and all-cause mortality. Methods Retrospectively multicenter cohort study included 211 patients with HFrEF and CIEDs, between 2010 and 2020. This study population was divided into two specific groups: Group A including patients with RM data and Group B including patients who receive usual care at regular hospital consultations. RM technology applied used different parameters to access the risk of worsening HF and stablishing an alert threshold. Results Out of 211 patients enrolled, 75% were male and 44.8% were in NYHA functional class II at the time of device implantation. One-hundred and twenty (56.9%) received in-home monitoring system (89% Latitude® and 10.8% Carelink®), corresponding to the Group A. The remaining 91 patients (43.1%) were included in Group B. Forty-nine patients (40.8%) had transvenous implantable cardioverter defibrillator (ICD), 13 (10.8%) had a subcutaneous ICD, 54 (45%) a cardiac resynchronization therapy (CRT) defibrillator and 4 (3.3%) a CRT pacemaker. Group A patients did not have coronary artery disease (p 0.047) and were younger than patients in Group B (median age 66 years, IQR 55 – 73; median age 70 years, IQR 63 – 77). No other statistically differences in main comorbidities were detected between groups. The number of atrial fibrillation (AF) episodes and AF burden was higher in Group A during the follow-up (p 0.006) as well as non-sustained ventricular tachycardia episodes (p 0.016). However, no differences were accessed in emergency department (ED) admissions or heart failure hospitalizations (HFH) by decompensation for patients in group A who received alerts versus patients who not received (p 0.178 and p 0.748, respectively) nor between group A and B (p 0.921 and p 0.213, respectively). Patients in group A had a lower all-cause mortality rate (p &amp;lt; 0.001) and cardiovascular mortality (p 0.002), but no difference in life-threatening ventricular events occurred. Conclusion In our cohort of HF patients, remote monitoring allowed the premature detection and the correct quantification of arrhythmic events but did not reflect any difference in ED nor HFH by decompensation. Instead, RM system demonstrates ability to reduce global mortality when compared to conventional care. More data about the application of this system and the ideal tracking algorithms are necessary.

Cardiac Magnetic Resonance in myocarditis: besides the diagnosis?

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Patients with acute myocarditis (AM) can be at increased risk of adverse cardiac events after the index episode. Beyond its undoubted role in diagnosis, Cardiac Magnetic Resonance (CMR) can also provide additional prognostic information and contribute to the patients risk stratification. Methods Retrospective study with patients admitted with the clinical suspicion of myocarditis in our center from February/2018 to September/2021, in whom CMR was performed. A total of 48 patients were included and divided into two groups based on the number of segments with late gadolinium enhancement (LGE). The threshold (&amp;gt; or &amp;lt; than 5 segments) was determined according to ROC curve analysis. The primary outcome was a composite of all-cause mortality, heart failure and myocarditis recurrence. Results We included 48 patients (95,8% males; mean age 37,0±16,1 years old), 93,8% presenting with chest pain and 63,2% presenting with st-segment elevation on electrocardiogram. During hospitalization, 3 patients needed ionotropic support, 7 had supraventricular tachycardia, 9 non-sustained ventricular tachycardia, 1 sustained ventricular tachycardia, 1 needed extracorporeal membrane oxygenation and 9 had heart failure. CMR (performed 6 days (median) after admission) showed LGE in 45 patients (93,8%) and mean left ventricular ejection fraction (LVEF) of 55,5±8,7%. Both groups had similar age (35,0±13,7 vs 38,5±17,6 years, p=0,45), cardiovascular risk factors, st-segment elevation at admission (61,9% vs 63,0%, p=0,38), pro-BNP levels at admission [286 (IQR 144-699) mg/dl vs 522 (IQR 222-1253) mg/dl, p = 0,20] and peak C-reactive protein [5,7 (IQR 4-12) vs 5,2 (IQR 2,6-12,5),p=0,77]. Patients with LGE in ≥5 segments (56,3%) had lower LVEF (53,2±9,6 vs 58,2±6,6, p=0,02), had more non-sustained ventricular tachycardia episodes (29,6% vs 4,8%, p=0,03), incidence of heart failure during hospitalization (25,9% VS 9,6%, p=0,19) and higher peak troponin levels [1,54 (IQR0,64-2,45) vs 0,594 (IQR 0,374-1,07), p=0,002]. During a median follow-up of 21,5 (IQR 8–35,2) months, 11 patients (22,9%) experienced the primary outcome (6 for heart failure, 4 for AM recurrence, 1 death). The incidence of the primary endpoint increased by 1,20 (95% CI 1,08-1,60) for each segment involved. Patients with ≥ 5 segments had a higher incidence of this outcome (25,7 vs 5,1 per 100 patient/year, log rank p=0,02). After adjusting for possible cofounders, LGE≥ 5 segments on CMR was an independent predictor of all-cause mortality, heart failure and myocarditis recurrence (HR 7,22, 95% CI 1,33-39,16). Conclusion In this study, LGE involving 5 or more segments by LGE was correlated with adverse cardiovascular events among patients with suspected myocarditis. These data suggest that cardiac resonance imaging might add value to currently existing diagnostic tools for risks assessment in AM.

PO-03-223 EXTENDED AMBULATORY ECG MONITORING ENHANCES IDENTIFICATION OF HIGHER-RISK PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY

In the 2020 AHA/ACC hypertrophic cardiomyopathy (HCM) guidelines, a 24 or 48 hour continuous ambulatory ECG monitor is recommended for risk stratification to detect nonsustained ventricular tachycardia (NSVT), with greatest weight placed on frequent, long, and/or rapid runs as a sudden death (SD) risk marker. ECG monitoring devices with extended wear capability are now available, although the utility of longer monitoring in HCM is uncertain. To evaluate the prevalence, burden and clinical significance of NSVT identified during initial 48 hours of continuou ambulatory monitoring compared to 14 days. We evaluated 236 HCM patients (49 ± 12 years; 72% male) without primary prevention ICDs judged previously to be at low or intermediate SD risk with 14-day continuous ambulatory monitoring (Zio-patch XT, iRhythm Technologies). Episodes of NSVT were evaluated during the initial 48 hours of monitoring and compared to NSVT identified in subsequent 2 to 14 days. NSVT episodes with ≥1 of the following criteria was considered higher risk as a SD marker: ≥ 200 bpm, ≥ 8 beats, ≥ 3 runs within consecutive 48 hour period. Among the 236 patients, 114 (48%) had ≥ 1 runs of NSVT, with a median of 2 runs (IQR: 1-4) during the complete monitoring period, including 86 patients with ≤ 4 runs (36%), 13 with 5-9 runs (6%), and 15 with ≥10 runs (7%). Median length of NSVT was 7 beats (5-13) at 167 bpm (148-186). Diagnostic yield of detecting NSVT was 18% during the first 48 hours of monitoring compared to 48% at 14 days, with 63% of the initial NSVT episodes occurring after the first 48 hours (72 of 114). Similarly, diagnostic yield of detecting high risk NSVT episodes was 8% during the first 48 hours as compared to 24% at 14 days, with 64% of the initial high-risk NSVT runs occurring after the first 48 hours (36 of 56). There was no significant difference in clinical profile between patients with NSVT at < 48 hours and those with NSVT from 2-14 days, including age or presence of ≥1 major SD risk markers. In HCM, prevalence of NSVT is common, occurring in nearly half of patients over 14 days of continuous monitoring. Diagnostic yield for detecting NSVT was substantially increased using 14 days of monitoring, with 48 hours of monitoring missing nearly two-thirds of patients with high risk NSVT episodes that impact risk stratification. These data support 14-day ambulatory monitoring periods to enhance identification of higher risk HCM patients.

PO-04-231 THERAPIES DELIVERED BEFORE AND AFTER NONINVASIVE CARDIAC RADIOABLATION: A SECONDARY ANALYSIS OF THE ENCORE-VT TRIAL

Noninvasive Cardiac RadioAblation (CRA) is a new therapy for refractory ventricular tachycardia (VT) that delivers focused radiation to VT-related myocardial scar. Because CRA reduced VT events, we hypothesize therapies will be reduced. To compare type and number of therapies delivered before and after cardiac radioablation in patients with scar-based VT. This was a retrospective analysis of ICD interrogations from the ENCORE-VT trial (NCT02919618), where patients with high-burden of VT were treated with 25 Gray/1 fraction to myocardial scar nearest the VT exit site. For each patient, all device-identified VT episodes which required therapy were reviewed for the 6-month period prior to CRA and 6-month period after (excluding 6-week blanking period). Episodes of non-sustained VT, non-treated VT, or VF were excluded. Type and number of therapies derived from device review were used for primary comparison. Of the 19 patients enrolled into the trial, 16 were included for analysis (excluded 2 patients treated for PVCs, 1 patient death in first 6 months). Cohort analysis (Top Figure) using Student’s t-test showed statistically significant reduction in VT episodes (P 0.0006) and antitachycardia pacing (ATP) therapies (P 0.0004) post therapy and a greater than 78% reduction in shocks. Compared to pre-treatment (Bottom Figure), by percentage, ATP terminated VT more often post-treatment with two or fewer sequences. Three of more ATP sequences were seen, by percentage, more often pre-treatment as compared to post-treatment. Compared to before cardiac radioablation, episodes of VT and number of therapies for VT were significantly reduced. In addition, when VT did recur post-treatment, it was more susceptible to termination by two or fewer ATP sequences.

PO-04-015 BIVENTRICULAR ARRHYTHMOGENIC CARDIOMYOPATHY ASSOCIATED WITH A NOVEL HETEROZYGOUS PLAKOPHILIN-2 EARLY TRUNCATING VARIANT

N/A N/A N/A A 31-year-old male patient suffered from palpitations, which occurred particularly during and shortly after physical activity. The patient was very athletic and took part in marathons. His family history was unremarkable. The electrocardiogram showed T wave inversions in V1-V3 (Figure 1A). During bicycle ergometry monomorphic premature ventricular complexes (PVC) and non-sustained ventricular tachycardia episodes (left-bundle branch block morphology, inferior axis) evolved (Figure 1B, black arrow). Of note, under maximal physical stress a second PVC with a right-bundle branch block morphology occurred (Figure 1B, red arrow) suggesting left ventricular (LV) involvement. Echocardiographic evaluation showed a dilated right ventricle (RV) with reduced systolic function, a subtricuspid aneurysm and multiple sacculations of the RV free wall (Figure 1C-D, white markers). Cardiac magnetic resonance imaging (MRI) confirmed the right ventricular findings (Figure 1E, red arrows). In addition, late gadolinium enhancement and fatty deposits were visible in the LV lateral wall (Figure 1F-G, yellow arrows and blue asterix). Genetic testing was performed using a panel covering 173 genes (Agilent, SureSelectQXTTarget Enrichment) and next generation sequencing (NGS) (Illumina MiSeq). It revealed a novel heterozygous nonsense variant in the plakophilin-2 (PKP2) gene (808C>T p. (Gln270Ter) in exon 3) that causes an early truncation, which was confirmed by Sanger sequencing. It was classified as pathogenic (class V). Cascade screening of the asymptomatic patient’s mother (64-y-old), father (70-y-old) and sister (33-y-old) showed that the patient's father and sister harbored the same PKP-2 variant. Both did not report a history of participating in competitive sports, and thorough cardiac evaluation of these two genotype positive family members showed normal findings. Previous studies have indicated that early truncation of the PKP2 C-terminus likely causes arrhythmogenic right ventricular cardiomyopathy (ARVC) irrespective of transcript position. Although desmosomal and non-desmosomal variants create certain genetic potential for the development of ARVC, exercise has an important role in determining the development, severity, and pattern of phenotypic expression. The fact that the only index patient, as a marathon runner, developed ARVC, suggests that the novel PKP2 variant poses a genetic risk, but is not sufficient for inducing an ARVC phenotype by itself.

462 RELATIONSHIP BETWEEN PATIENT GENOTYPE, VENTRICULAR INVOLVEMENT AND SUDDEN CARDIAC DEATH IN PATIENTS WITH ARRHYTHMOGENIC CARDIOMYOPATHY

Abstract Introduction Arrhythmogenic cardiomyopathy (AC) is an important cause of sudden cardiac death (SCD). AC is characterized by areas of fibro-fatty replacement of the myocardium of one or both ventricles, which can be characterized through cardiovascular magnetic resonance (CMR). Several mutations have been associated with the development of AC, most commonly in desmosomal genes. The relationship between the genotype and the disease phenotype (i.e., the extent and severity of myocardial disease and patient outcome) is unclear. Methods We evaluated 280 consecutive patients evaluated in a single CMR laboratory over a 10-year timespan and diagnosed with AC according to the Padua criteria, based on a retrospective evaluation of the electronic health records. All these patients had undergone a genetic testing through Sanger sequencing or Next Generation Sequencing (after 2012). Pathogenic or likely pathogenic mutations and variants of unknown significance were considered. CMR scans performed at diagnosis were examined by an expert blinded to the results of genetic testing to retrieve the location and extent of the areas of fibro-fatty replacement and late gadolinium enhancement (LGE), biventricular volumes and function. Follow-up data were also retrieved. The primary endpoint was SCD or aborted SCD (following successful defibrillator discharge). The secondary endpoint included SCD or aborted SCD plus sustained or non-sustained ventricular tachycardia episodes. Results Patients were more often males (67%), with a mean age of 48±16 years. Gene mutations related to cardiomyopathy were found in 123 patients, and 85 patients harbored mutations in desmosomal genes (DSP, n=41; DSG2, n=16; PKP2, n=16; DSC2, n=6; JUP, n=6), while the other mutations were in genes including TMEM43, LMNA, SCN5A, MYH7, and RYR2. Patients with mutations in desmosomal genes had more often LGE in the left ventricle (LV) than patients with other mutations or with no mutations detected (66% vs. 58% vs. 46%, respectively; p=0.025). Patients with mutations in the DSP gene had a greater LGE extent in terms of number of segments affected (p=0.011), or percent of the LV (p&amp;lt;0.001) compared with patients with other desmosomal mutations or no mutations. No differences between patients with desmosomal or non-desmosomal mutations or no mutations were found in terms of fibro-fatty replacement in the LV (51% vs. 32% vs. 48%; p=0.577), nor in terms of LGE presence or fibro-fatty replacement of the right ventricle (RV; data not shown). Median follow-up duration was 4.4 years (interquartile range 1.8-6.4); 22% of patients underwent defibrillator implantation. Primary endpoint events were recorded in 21 patients (7.5%), with 20 aborted SCD episodes. The secondary endpoint occurred in 58 patients (21%). At Cox regression analysis, the mutation status did not reach statistical significance as univariate predictor of the two endpoints, but LGE in the LV, LGE in ≥2 LV segments, or LGE &amp;gt;9% (considered one at the time) independently predicted both endpoints. Conclusions In patients with AC, mutations in desmosomal genes are found in almost half of patients, and are associated with the presence and a larger extent of LGE in the LV. In turn, the presence and extent of LGE are independent predictor of SCD or aborted SCD.

Abstract 15725: Non Existing Pacemaker: A Complication of Kyphoplasty

Introduction: Diagnosis of cement emboli remains challenging due to heterogenicity of diagnostic findings. We describe a case of cement embolism interpreted as abandoned pacemaker leads. Case description: A 76-year-old female underwent lumbar kyphoplasty. In the post-anesthesia care unit, she developed multiple asymptomatic episodes of non-sustained ventricular tachycardia. Her lab work including basic metabolic panel, electrolytes, and troponin was unremarkable. A transthoracic echocardiogram (TTE) revealed intracardiac foreign body interpreted as abandoned pacemaker wires originating at the superior vena cava with one terminating in the right ventricular (RV) apex and the other in the right atrial (RA) appendage (Figure 1). Chest computer tomography (CT) confirmed intracardiac pacemaker wires. The patient denied any history of pacemaker placement. TTE and CT images were reviewed again with multiple other opinions stating that the foreign body represented dense cement from the vertebral body. It exited through a paravertebral vein into the inferior vena cava making its way to the right heart (Figure 2). Coronary angiography confirmed an elongated cement embolus. The patient underwent cement removal through sternotomy. Conclusions: Diagnosis of cement embolism may remain challenging as it can mimic any foreign bodies including pacemaker wires. Suspicion for the diagnosis should remain high in any patient who underwent kyphoplasty and developed cardiac arrhythmias or other cardiac symptoms. Image 1. A - Pacemaker lead passing through RA to the RV. Image 2. A- cement material in the right heart. B- Cement extravasating through right paravertebral vein.

Abstract 15052: A Young Patient Who Presented With Dilated Cardiomyopathy and Renal Infarction During Treatment With Isotretinoin

Background: Isotretinoin or 13-cis-retinoic acid (RA) is one of the most effective and widely used drug for the treatment of severe acne vulgaris. Despite deemed safe, no definite consensus has been reached on the cardiovascular risk of RA derivatives. We describe the first case of concomitant dilated cardiomyopathy (DCM) and renal infarction after 5 months of isotretinoin use in a previously healthy 18-years old man. Case Summary: An18-years-old man, with history of acne vulgaris, presented in August 2021 to our emergency department because of left iliac fossa pain and effort dyspnea. Computed tomography scan revealed left renal infarction and echocardiogram demonstrated global left ventricular (LV) dilatation with severely reduced LV-ejection fraction (LVEF: 29%). Coronary artery disease, autoimmune, infective, or heritable causes of DCM were ruled out. Cardiac magnetic resonance evidenced LV circumferential mid-wall late gadolinium enhancement and ECG monitoring revealed several non-sustained ventricular tachycardia episodes. Thus, Bisoprolol, Sacubitril/Valsartan, and Eplerenone were started and up titrated until maximum tolerated doses, with only poor LVEF improvement. Conclusion: Our case aims to raise awareness on rare life-threatening cardiovascular events associated with isotretinoin use for the treatment of severe acne in young patients. To the best of our knowledge, this is the first described case of renal thromboembolism and DCM requiring S-ICD implantation and cardiac transplant program listing occurring in the course of isotretinoin treatment.