Prevention Of Sudden Cardiac Death Research Articles

Subcutaneous implantable cardioverter-defibrillator generator removal: a multicenter analysis

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): University Hospital Cologne Introduction The subcutaneous implantable cardioverter-defibrillator (S-ICD) was a significant recent advance in sudden cardiac death prevention. Device-related complications, including infection or lead fracture, or changes in the medical status, such as necessity for cardiac pacing, may necessitate device removal. (1) Real-world multicenter data on S-ICD removal are sparse. Purpose This multicenter analysis sought to assess the incidence and indications for S-ICD generator removal. Methods Retrospective data and the most recent follow-up data on S-ICD devices implanted at 14 participating centers in Europe, the US and Canada, and information on subsequent device removal was submitted to an online database (2). Limited baseline patient information and the incidence of and reasons for S-ICD generator removal or failure were reported. Premature device removal was defined as device removal for any reason other than regular battery depletion (>5 years of longevity). Results Data from 1106 devices was analyzed. Devices were implanted between 15.10.2009 and 16.04.2021 at the participating centers. The first-generation model 1010 generator was implanted in 55 (5%), the newer models A209 or A219 were implanted in 457 (41.3%) and 594 (53.7%) respectively. Patients were aged 46.7±16.1 years and the indication for ICD therapy was primary prevention in 616 (55.7%) and secondary prevention in 484 (43.8%). During the follow-up period, 37 (3%) patients deceased, and 96 patients were excluded from the analysis due to lack of follow-up (<4 weeks). Premature device removal was performed in 103 (9.3%) during the follow-up period of 31.3±19.5 months. The most common reasons for removal were battery depletion (52%), of which premature, defined as <5 years longevity, depletion accounted for 57%, upgrade to transvenous ICD or CRT (17%) and infection (11%). Other indications for removal included heart transplantation (4%) or ventricular assist device implantation (1.5%), noise detection or inappropriate shocks (6.5%), and patient discomfort (0.7%). (see figure 1) Regular battery depletion occurred in 34 devices after 69.2±5.3 months. There was no difference in device longevity between the different generator models (1010, A209, and A219). There were no significant differences between the different generator models with respect to indications for explanation. Conclusions In this real-world retrospective multicenter analysis, premature S-ICD generator removal was necessary in 9.3% of patients. Premature battery depletion, infections, and the need for pacing were the most common indications for unplanned generator removal.

Improved patient selection for primary prevention ICD implantation by predicting ICD non-benefit using artificial intelligence

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NWO Rubicon (452019308) Amsterdam Cardiovascular Sciences Background Left Ventricular Ejection Fraction (LVEF) is suboptimal as a sole marker for predicting sudden cardiac death (SCD) or benefit from an ICD. Machine (ML) and deep (DL) learning provide new opportunities for personalised predictions using complex, multi-modal physiological data. Objective We hypothesise that risk stratification for ICD implantation can be improved by ML and DL models that combine clinical variables with time series features from 12-lead electrocardiograms (ECG). Methods We present a multicentre study of 1010 patients with an ischaemic, dilated or non-ischaemic cardiomyopathy and LVEF≤35% implanted with an ICD between 2007 and 2021 for primary prevention of SCD (64.9 ±10.8 years, 73.2% male) in two academic hospitals. For each patient, raw 12-lead, 10-second ECG-recordings obtained <90 days before ICD implantation and clinical details were collected. Supervised ML and DL models were trained and validated using stratified k-fold cross-validation (5 repeats, k=10) on a development cohort (n=550) from Hospital A. We used this model to predict ICD non-benefit defined as mortality without prior appropriate ICD-therapy on an external dataset from Hospital B (n=460). Kaplan-Meier survival analysis stratified by high vs. low predicted probability using Youden's J statistic as cut-off was performed. Results At 3-year follow-up, 16.0% of patients had died of whom 72.8% met the criteria for ICD non-benefit. Extreme gradient boosting models identified subjects with ICD non-benefit with an area under the receiver operator curve (AUROC) of 0.897 ±0.05 during internal validation (Figure 1, solid line). In the external cohort, the AUROC was 0.793 (95% CI 0.75-0.84) (Figure 1, dashed line). Survival analysis for low vs. high predicted risk indicated ICD non-benefit rates of 6.0% versus 30.3% at 3-year follow-up, respectively (Figure 2). Conclusion A ML model that combined clinical with ECG features better predicted ICD non-benefit at 3-years in a primary prevention population than currently available risk scores such as the MADIT-ICD score. This approach may provide new tools to support personalized decision making for ICD therapy. Prospective validation is needed to assess the real-world clinical performance of the model.

Standard and extended electrocardiographic screening for the subcutaneous implantable cardioverter-defibrillator

Abstract Funding Acknowledgements Type of funding sources: None. Background The subcutaneous implantable cardioverter-defibrillator (SICD) is effective therapy for sudden cardiac death prevention. The condition for implantation is an electrocardiographic screening test before procedure (ECG-s). Patients who don’t pass are regarded to be at risk of inappropriate detection of tachyarrhythmias with inappropriate interventions. A patient is considered suitable for implant if at least one surface ECG lead (sense vector) is acceptable for all tested postures. Objective The aim of the study was to identify the incidence of failure, the predicting factors and clinical importance of extended ECG-s with right sided lead position and lying on the left and right side of the body. Methods ECG-s to determine suitability for SICD is based and performed using a manufacturer –specific measurement tool. We performed this test in 75 consecutive pts with indication for SICD therapy on the basis of standard manufacturer protocol(lead at the left sternum border: sitting, standing and lying position), and extended for right sternal lead location and two additional body position: lying on the left and right side (10 position for each individual). We analyzed: age, gender, body mass index(BMI), heart rate, heart rhythm(sinus/atrial fibrillation), QRS duration, PR interval, corrected QT interval(QTc), echocardiography parameters, etiology. Results ECG-s failure occurred in 6/75(8%) of patients. Screening results: 1 vector failure rate with the standard device and lead positions: primary(P) 12%, seconadary(S) 17%, alternative(A) 40%, P vs. A and S vs. A p<0,001. Testing with an electrode positioned on the right sternum border- 1 vector failure: (P) 10%,seconadary(S) 17%, alternative(A) 48%, P vs. A and S vs. A p<0,001. In case of failure on left side 50%, 14% and 6% of pts passed the test with the right sided lead position for P, S and A vector respectively, p<0.001. Identified factors predicting ESG-s passing vs. failure included: QTc interval 445,32±35,4 vs. 480,6±37,6 ms for any vector(p=0,034), BMI:26,7±4,7 vs. 29,9±4,7 for vector A( p=0,008 ), EF: 43,3±20,1 vs. 34,0±16,2 for vector A( p=0,027). Sense vector failure rate with the left sternal lead location lying on the left and right side of the body was concordant with the rate lying on the back, p=0,05. For the right parasternal lead location the rate failure was lower lying on the right side for all sense vectors: P, S and A(p=0,045; 0,083 and 0,020) respectively. Conclusions ECG screening failure rate for SICD is comparable with previous reports. The right sternal lead location screening is effective and enables important clinical findings before implantation and in case of lead reposition( defibrillation threshold test failure) during procedure. We recommend to screen routinely on both sternum borders. Some additional body position testing: lying on the left and right side of the body, mimicking sleeping/rest could be an important element to determine eligibility for SICD.

Hypertrophic cardiomyopathy in an athlete, occurring under the mask of sports remodeling. Secondary prevention of sudden cardiac death. Analysis of a clinical case

HCMP is a severe heart disease characterized by high rates of sudden mortality, especially in young people. Optimization of the tactics of treatment of children with HCMP in order to improve the prognosis remains one of the urgent tasks of cardiology. A clinical case of a 15-yearold boy with moderate myocardial hypertrophy and an asymptomatic course of HCMP is presented, in connection with which the disease was not diagnosed for a long time. The boy was engaged in professional sports, during the competition he suddenly lost consciousness, clinical death occurred. Only timely resuscitation measures allowed to save the patient’s life. Implantation of a cardioverter defibrillator was performed as a secondary prevention of SCD (class 1 indications). The importance of timely examination of asymptomatic athletes with myocardial hypertrophy for differential diagnosis between HCMP and myocardial remodeling against the background of intense physical exertion (“athlete’s heart”) is emphasized. The importance of solving the issue of the inadmissibility of intense physical exertion, even with an asymptomatic course of HCMP, is shown. It should be remembered that it has been established that intense sports loads act as a trigger for cardiac arrest in patients with HCMP. Retrospective calculation of SCD risk based on HCM risc-SDD calculator/The BCC risk calculator at GCMP showed 3.19 %, which corresponded to a low risk. The possibility of SCD in patients with HCMP is emphasized, even with an estimated low risk, which requires further research to find predictors of an unfavorable outcome.

Hypertrophic cardiomyopathy in a girl with Danon disease

A prospective observation for 4 years (from 14 to 17 years) is presented for a girl with Danone’s disease. The early onset of the disease was noted, the clinical picture was dominated by syncopal and syncopal conditions. According to the clinical picture, presyncopal conditions were of a vasovagal nature, which was verified by the results of the Tilt test when the vasodepressor variant was detected. The disease was characterized by isolated cardiac disorders in the form of concentric hypertrophic cardiomyopathy, widespread fibrous changes in the myocardium. According to the standard ECG and daily ECG monitoring, ventricular preexitation syndrome was detected. Electrophysiological examination established the nodo-ventricular tract. Myopathy, cognitive impairment and visual changes were absent. A mutation in the heterozygous state was detected in exon 5 of 9 exons of the LMP2 gene, leading to the acquisition of a premature stop codon, was identified. X:g.119581719G>A ENST00000434600.2: c.718C>T. The mutation was verified by Sanger. The case in the pedigree is sporadic. As a prevention of sudden cardiac death, implantation of a cardioverter-defibrillator was performed. Effective relief of induced stable ventricular fibrillation (Burst stimulation protocol) was achieved only with the use of a ventricular electrode with two shock coils.

Experience of maintaining the electronic register of young athletes in St. Petersburg with cardiovascular diseases

Early diagnosis of cardiovascular diseases in people involved in sports, and dynamic monitoring of them are important for the primary prevention of sudden cardiac death. Our study presents clinical and instrumental information about the health status of young athletes with various cardiovascular abnormalities. Continued long-term prospective follow-up of underage athletes will contribute to the adoption of optimal decisions in the individual assessment of the athlete’s condition, aimed mainly at protecting the health of a young athlete, as well as developing his sports career.

Implantable cardioverter defibrillator for primary prevention in patients with non-ischemic cardiomyopathy in the era of novel therapeutic agents- meta-analysis.

Evidence regarding the mortality benefit of implantable cardioverter defibrillator (ICD) non-ischemic dilated cardiomyopathy (NIDCM) is inconsistent. The most recent randomized study, the DANISH trial, did not find improved outcomes with ICD. However, based on previous studies and meta-analyses, current guidelines still highly recommend ICD implantation in NIDCM patients. The introduction of novel medications for heart failure improved the clinical outcome dramatically. We aimed in this study to evaluate the effect of Angiotensin Receptor-Neprilysin Inhibitors (ARNi) and sodium-glucose transport protein 2 inhibitors (SGLT2i) on the mortality benefit of ICD in NIDCM. We used a previous metanalysis algorithm and added an updated comprehensive literature search in PubMed for randomized control trials that examined the mortality benefit of ICD in NIDCM vs. optimal medical treatment. The primary outcome included death from any cause. We did a meta-regression analysis to search for a single independent factor affecting mortality. Using previous data, we evaluated the theoretical effect of ICD implementation on patients treated with SGLT2 inhibitors and ARNi. No new articles were added to the results of the previous meta-analysis. 2,622 patients with NIDCM from 5 cohort studies published between 2002 and 2016 were included in the analysis. 50% of them underwent ICD implantation for primary prevention of sudden cardiac death, and 50% did not. ICD was associated with a significantly decreased risk for death from any cause compared to control (OR = 0.79, 95%CI: 0.66-0.95, p = 0.01, I2 = 0%). The theoretical addition of ARNi and the SGLT2 inhibitor dapagliflozin did not change the significant mortality effect of ICD (OR = 0.82, 95%CI: 0.7-0.9, p = 0.001, I2 = 0%) and (OR = 0.82, 95%CI: 0.7-0.9, p = 0.001, I2 = 0%). A meta-regression revealed no association between death from any cause and left bundle branch block (LBBB), use of amiodarone, use of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers, year initiated enrollment, and the year ended enrollment (R2 = 0.0). In patients with NIDCM, the addition of ARNi and SGLT2i did not affect the mortality advantages of ICD for primary prevention. https://www.crd.york.ac.uk/prospero/, identifier: CRD42023403210.

P160 WHEN IMPEDANCE TRENDS LIE, REMOTE MONITORING HELPS FOR DIAGNOSIS

Abstract An 82–years old female patient with history of hypertension, diagnosis of dilatative cardiomyopathy with normal coronary arteries and permanent atrial fibrillation (AF) was implanted with a dual chamber implantable cardioverter defibrillator (ICD), Guidant Ventak Prizm DR (Boston Scientific,Marlborough,USA) as a secondary prevention of sudden cardiac death in 2002. The ICD was electively replaced in 2005 and in 2010 with a Guidant, Vitality 2 DR (Boston Scientific,Marlborough,USA). In 2016, despite an optimized medical therapy, the patient experienced an episode of palpitation due to an AF with high ventricular response. Considering the difficulties of the heart rate management with the pharmacological therapy the patient underwent to an ablation of AV node. In 2017 we performed a third replacement of the ICD downgrading the system to a single chamber ICD, Fortify Assura VR (Abbott,Sylmar,USA) and providing the patient with a bedside–transmitter Merlin@home (Abbott,Sylmar,USA) The patient, followed for 4 years remotely, did not experience ventricular arrhythmias and the ventricular lead electrical parameters, including pacing and shock impedances, were stable and in the normal range. In March 2021 an alert of the Merlin system triggered an unscheduled transmission that showed several episodes of ventricular oversensing. The episodes revealed that an electrical interference inhibited the ventricular pacing causing episodes of asystole with a maximum duration of three seconds (Fig.1). Unexpectedly electrical parameters such as the pacing and shock impedances showed a stable and normal measurements (Fig .2), while the chest X–rays showed that the ventricular lead was kinked at 90–degrees below the clavicle evidencing a lead fracture (Fig.3). The patient was therefore implanted with a new ventricular lead avoiding inappropriate shocks and further episodes of asystole. The occurrence of a lead failure represents an insidious and potentially harmful event for the device implanted population, especially for ICD or pacemaker–dependent patients. The diagnosis of a lead failure is not easily predictable, and it is usually driven after a clinical event of inappropriate shock or unexplained syncope. Our case highlighted how Remote Monitoring is extremely helpful even more in this case of apparently correct functioning based on electric measurements.

P266 SUBCUTANEOUS DEFIBRILLATOR USE LIMITATION IN PATIENT AFFECT BY ARRHITMOGENIC CARDIOMYOPATHY IN REAL WORLD

Abstract Introduction The prevention of sudden cardiac death (SCD) through the implantation of a defibrillator (ICD) represents one of the fundamental milestones in the management of arrhythmogenic cardiomyopathy (ACM). Individual characteristics of the patient and of the disease can help in the selection of the device [transvenous (TV) or subcutaneous (S–ICD) defibrillator]. The objective of this study is to evaluate the major factors limiting S–ICD implantation in a real–world ACM patient population. Methods This multicenter retrospective observational study enrolled consecutive patients undergoing ICD implantation in primary or secondary prevention for ACM at the participating centers. The population was subdivided according to the execution of the preimplant S–ICD screening test and its result. Baseline clinical and instrumental data were analyzed to identify predictors of passing the screening test. Results 21 ACM patients (67% men) who underwent 24 S–ICD or TV–ICD implant procedures were enrolled. 70.8% of patients (N=17) were screened for S–ICD. Screening was not performed in 4 patients (17%): in one case due to an indication for resynchronization therapy and in three patients because they were implanted in the pre–S–ICD era. Screening failed in 53% of cases. The cause of the failures were the low voltages of the QRS (100% of the failures) and a poor stability of the trace in the different positions tested for significant variation of the QRS/T ratio (37.5% of the failures). No significant difference was noted between the clinical and instrumental characteristics of the two subgroups (Table 1), although the patients who passed the screening showed a trend towards a greater QRS amplitude in DI (0.52±0.29 vs 0.28±0.17 mV – P= 0.07) and to present a positive QRS in DI (100% vs 50%; P=0.08 – Table 2). Conclusions The use of the S–ICD in patients with ACM could be limited by some intrinsic characteristics of the disease. In a real–world cohort of patients affected by ACM, the presence of low QRS voltages on the surface ECG and positional morphology variations allowed S–ICD use in half of the patient candidates.

P325 CARDIAC SARCOIDOSIS PRESENTING WITH ATRIOVENTRICULAR BLOCK AND SUBSEQUENT CARDIAC ARREST: A CASE REPORT

Abstract A 53–year–old male patient with no significant past medical history and no familiar history for cardiac diseases presented to the emergency department for asymptomatic bradycardia. The ECG showed complete atrioventricular block in the absence of pathological findings on the echocardiogram and no coronary lesions were found on coronary angiography. The patient underwent pacemaker (PM) implantation. A few months later the patient suffered from cardiac arrest in sustained ventricular tachycardia, effectively treated with DC shock. The echocardiogram showed mild right ventricular dilation and dysfunction with regional wall motion abnormalities, especially in the subtricuspid site. Cardiac magnetic resonance imaging (MRI) showed focal areas of delayed enhancement with a non–ischaemic pattern and distribution with a hook sign, highly suggestive of cardiac sarcoidosis. FDG PET showed cardiac, hepatic, splenic, and lymph nodal uptake. In the suspicion of systemic sarcoidosis, an hepatic biopsy was performed, being the liver the most accessible site. The histological examination showed the presence of non–caseating granulomas. Therefore, a diagnosis of Systemic Sarcoidosis (SS) with Cardiac involvement was made and the PM was upgraded to CRT–D in secondary prevention. The patient was discharged with cortisone therapy. Three months after discharge, a new total body PET–CT scan was performed and showed, in comparison to the previous one, the absence of areas of significant hypermetabolism in the cardiac, hepatic and bone fields. Cardiac sarcoidosis (CS) is a rare inflammatory granulomatous myocardial disease of unknown etiology that should be suspected in young patients with atrioventricular conduction disturbances and complex ventricular arrhythmias. The diagnostic approach is challenging: imaging techniques (MRI, PET) can be suggestive of CS but biopsy with histological demonstration of the non–caseous granuloma is mandatory. Endomyocardial biopsy (which has suboptimal sensitivity due to focal lesion) could be avoided if there is a more accessible and less invasive extracardiac site for biopsy. Early diagnosis relies on multidisciplinary collaboration and is essential for staging and long–term management of the disease and prevention of sudden cardiac death. Cortisone therapy remains the mainstay of treatment.

T-wave alternans: an ominous pattern for malignant arrhythmias.

We report on a patient with a history of chronic heart failure caused by atrial fibrillation, who developed macrovolt T-wave alternans (TWA) and subsequent malignant arrhythmia after amiodarone treatment. The presence of TWA and QT alternans disappeared after discontinuation of amiodarone and appropriate magnesium replacement. Macroscopic T-wave alternans (TWA) is present when there is visible variation in the amplitude and/or polarity of T waves between beats in the absence of QRS alternans. TWA signifies significant vulnerability during repolarization and may be a harbinger of impending electrical instability. Although macroscopic TWA is not frequently encountered in routine clinical practice. Prompt identification is essential for proper management and prevention of malignant ventricular arrhythmias and sudden cardiac death.

ANMCO position paper: guide to the appropriate use of the wearable cardioverter defibrillator in clinical practice for patients at high transient risk of sudden cardiac death.

Extended risk stratification and optimal management of patients with a permanently increased risk of sudden cardiac death (SCD) are becoming increasingly important. There are several clinical conditions where the risk of arrhythmic death is present albeit only transient. As an example, patients with depressed left ventricular function have a high risk of SCD that may be only transient if there will be a significant recovery of function. It is important to protect the patients while receiving and titrating to the optimal dose the recommended drugs that may lead to an improved left ventricular function. In several other conditions, a transient risk of SCD can be observed even if the left ventricular function is not compromised. Examples are patients with acute myocarditis, during the diagnostic work-up of some arrhythmic conditions or after extraction of infected catheters while eradicating the associated infection. In all these conditions, it is important to offer a protection to these patients. The wearable cardioverter defibrillator (WCD) is of particular importance as a temporary non-invasive technology for both arrhythmia monitoring and therapy in patients with increased risk of SCD. Previous studies have shown the WCD to be an effective and safe therapy for the prevention of SCD caused by ventricular tachycardia/fibrillation. The aim of this ANMCO position paper is to provide a recommendation for clinical utilization of the WCD in Italy, based upon current data and international guidelines. In this document, we will review the WCD functionality, indications, clinical evidence, and guideline recommendations. Finally, a recommendation for the utilization of the WCD in routine clinical practice will be presented, in order to provide physicians with a practical guidance for SCD risk stratification in patients who may benefit from this device.

P162 ARRHYTHMIC MITRAL VALVE PROLAPSE OCCURRING AS ABORTED SUDDEN CARDIAC DEATH

Abstract Mitral valve prolapse (MVP) is the common valvular heart disease, with a prevalence about 1–3% in the population. MVP is characterized on echocardiography by an abnormal systolic displacement of mitral valve leaflets into left atrium (LA) ≥ 2 mm above the mitral annulus. We described a clinical case of a 15 years–old boy with a first clinical presentation of out–of–hospital cardiac arrest related to ventricular fibrillation (VF) with a successful resuscitation after 2 DC shocks. Retrospectively, an episode of loss of awareness reported as post–minational. No familiar history of sudden cardiac death (SCD) or MVP was noticed. In the emergency room, the patient was hemodynamically unstable and was sedated and intubated. The surface electrocardiogram (ECG) showed sinus rhythm, QRS with fragmentation, and frequent monomorphic isolated premature ventricular contractions (PVCs) with RBBB/LAFB configuration.Frequent monomorphic PVCs with bigeminy was observed during continuous ECG monitoring, so the patient was treated with magnesium sulphate and metoprolol. The patient was subsequently weaned from ventilation support, presenting good gas exchange and without neurological sequalae. The 24h Holter monitoring showed an average of 53 bpm, extremely rare supraventricular extrasystoles, high incidence of monomorphic PVCs (23% of the total beats) with 4 couplets. Transthoracic echocardiography documented normal size and thickness with systolic function (GLS –21%, mild asynchrony of posterior basal segments), bi–leaflet prolapse associated to mild–moderate mitral regurgitation, and mitral annular disjunction (MAD) of 6.2 mm. The late gadolinium enhancement cardiac magnetic resonance showed bi–leaflet prolapse with mild insufficiency and maximum MAD 9 mm, mild LA dilatation, and slightly dilated both ventricles, without regional wall motion abnormalities; no scar or fibrosis at the late gadolinium enhancement was observed. According to guidelines, the patient received a subcutaneous implantable cardiac defibrillator for the secondary prevention of SCD and maintained under betablockers in order to control the arrhythmic burden. The genetic sampling did not show any pathogenetic mutation potentially related to cardiomyopathies or channelopathies. This case show an arrhythmic MVP complex with probably posterior papillary muscle source. The early PVCs with R/T constituted a possible trigger of VF. The betablocker therapy exhibited a full suppression of extrasystolic burden.

Antithrombotic management in patients undergoing cardiac implantable electronic device implantation

Cardiac implantable electronic devices (CIEDs) are an established treatment option for arrhythmias, sudden cardiac death prevention, and heart failure. Approximately 1000 devices are implanted per million inhabitants in European countries each year. However, the main concern in patients with an indication for CIED implantation is frequently associated with comorbidities requiring antithrombotic medications. The invasive device implantation procedure represents a bleeding risk ranging from pocket hematoma to cardiac tamponade. On the other hand, temporary interruption of antithrombotic therapy increases the risk for thromboembolic events. Implanting CIEDs in patients on antithrombotic medications incites several clinical dilemmas of balancing thromboembolic risk against bleeding risk, as complications are associated with higher mortality rates in both aspects. The most common bleeding complication is pocket haematoma formation, which is associated with a prolonged hospital stay, higher cost, higher risk of pocket infection, and thus higher morbidity and mortality. Studies have shown that the heparin bridging strategy in patients on oral anticoagulants imposes a greater risk for pocket haematoma formation and no benefit in reducing thromboembolic events. Most procedures of CIED implantation can be performed safely with uninterrupted oral anticoagulants. Dual antiplatelet therapy increases the risk of pocket haematoma and should be avoided whenever possible.

Long <i>QT</i> Syndrome in Young Athletes

Long QT syndrome is a disease associated with a high risk of sudden cardiac (arrhythmic) death. The frequency of sudden cardiac death is approximately 1: 100,000 young athletes, while autopsies often do not detect changes, which indicates a primary arrhythmogenic death. The article describes two clinical cases of young athletes with prolongation of the QT interval. The possible causes of the long QT syndrome and the difficulties of diagnosing this syndrome in children and adolescents involved in sports are discussed. Regardless of the reasons leading to the prolongation of the QT interval, there is a risk of arrhythmic events. Timely diagnosis of long QT syndrome is the way to the primary prevention of sudden cardiac death in young athletes.

Potential favorable action of sodium-glucose cotransporter-2 inhibitors on sudden cardiac death: a brief overview.

The primary pharmacological action of sodium-glucose co-transporter 2 (SGLT2) inhibitors is to inhibit the reabsorption of glucose and sodium ions from the proximal tubules of the kidney and to promote urinary glucose excretion. Notably, several clinical trials have recently demonstrated potent protective effects of SGLT2 inhibitors in patients with heart failure (HF) or chronic kidney disease (CKD), regardless of the presence or absence of diabetes. However, the impact of SGLT2 inhibitors on sudden cardiac death (SCD) or fatal ventricular arrhythmias (VAs), the pathophysiology of which is partly similar to that of HF and CKD, remains undetermined. The cardiorenal protective effects of SGLT2 inhibitors have been reported to include hemodynamic improvement, reverse remodeling of the failing heart, amelioration of sympathetic hyperactivity, correction of anemia and impaired iron metabolism, antioxidative effects, correction of serum electrolyte abnormalities, and antifibrotic effects, which may lead to prevent SCD and/or VAs. Recently, as possible direct cardiac effects of SGLT2 inhibitors, not only inhibition of Na+/H+ exchanger (NHE) activity, but also suppression of late Na+ current have been focused on. In addition to the indirect cardioprotective mechanisms of SGLT2 inhibitors, suppression of aberrantly increased late Na+ current may contribute to preventing SCD and/or VAs via restoration of the prolonged repolarization phase in the failing heart. This review summarizes the results of previous clinical trials of SGLT2 inhibitors for prevention of SCD, their impact on the indices of electrocardiogram, and the possible molecular mechanisms of their anti-arrhythmic effects.

Impact of fibrosis extend on multiparametric assessment for ventricular arrhythmias risk in non-ischemic dilated cardiomyopathy

The consensus guidelines recommended implantable cardioverter defibrillators (ICD) for sudden cardiac death prevention in patient with non-ischemic dilated cardiomyopathy (DCM) and LVEF < 35%. However, recent data suggest that it will not affect prognosis. Some markers have identified patients with higher risk of ventricular arrhythmias independently of LVEF. Better optimization of risk stratification for sudden cardiac death and specify implantation criteria are necessary. We performed comprehensive cardiac evaluation including imaging to predict ventricular arrhythmias in a population of non-ischemic DCM. We conducted a monocentric retrospective study including 107 patients with non-ischemic DCM and implanted with ICD as primary prevention from 2013 to 2019. Primary outcome is composite of appropriate therapy by ICD for ventricular tachycardia and ventricular fibrillation or sudden cardiac death. All-cause mortality and LVEF progress are secondary outcome. Primary outcome occurred in 21 patients (20%). In univariate analysis, GFR especially when it is < 50 mL.min-1.1.73 m-2(HR 4.62, P = 0.003), right ventricle ejection fraction under 40% (HR 2.48, p 0.04), number of segments with LGE (HR 1.22, P < 0.001) especially when there are 3 or more (HR 5.47, P < 0.001) or subepicardial location (HR 3.33, P = 0.03) are associated with ventricular arrhythmias. In a multiparametric assessment, this study highlights one important parameter associated with ventricular arrhythmias in selected population of non-ischemic DCM and LVEF < 35%: the extend of myocardial fibrosis, especially with 3 or more segments with LGE. It supports the concept of “critical mass” of fibrosis necessary for initiation and maintenance of ventricular arrhythmias. It was demonstrated in ischemic heart disease but a threshold value remains to be determined in non-ischemic DCM. The main result (Fig. 1).

Value of programmed electrical stimulation in Brugada Syndrome: a cohort study

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Prognostic value of programmed electrical stimulation (PES) in Brugada Syndrome (BrS) remains controversial. Substantial controversy exists regarding usefulness of PES in identifying BrS patients at risk of sudden cardiac death (SCD). Implantation of an implantable cardioverter-defibrillator is the only reliable form of SCD prevention in this specific population Purpose To determine if induction of sustained ventricular arrhythmia (VA) in PES is a predictor of cardiac events (CE), defined as the composite of SCD, appropriate ICD therapy for VA or unexplained syncope. Methods A retrospective analysis of 34 patients with spontaneous or pharmacologically induced type 1 Brugada pattern, submitted to electrophysiology study with PES between 2015 and 2019 in a Portuguese Center, was performed. Patients were followed for 24 months. Hospital records and monitoring data from cardiac devices were consulted. The Mann-Whitney U test was used for median comparison between groups. Binary logistic regression through the stepwise method was performed to evaluate categorical features. Results 35% (n=12) and 27% (n=9) had spontaneous type 1 and type 2 Brugada pattern in basal electrocardiography, respectively. 23% (n=8) had VA induced by PES. The mean age was 51,2±12,3 years. 71% (n=24) were male. 15% (n=5) had history of cardiac syncope, and 27% (n=9) had a family history of SCD. 9% (n=3) were carriers of a SNC5A mutation. Mean AH time and HV time were, respectively, 105±31,9, and 49±8,5ms. During the 24 months of follow-up, 9% (n=3) suffered a CE (2 unexplained syncope and 1 SCD). None of the patients who suffered CE had VA inducible at PES study. There was no statistical significance in the occurrence of cardiac events when comparing both groups (VA induced in PES vs. no induced arrhythmia) (p=0,49, OR 0,89, IC 95% 0,70;1,02). Through binary logistics, adjusted for potential confounders (gender, history of syncope, history of family SCD and identification of a genetic variant), patients with spontaneous type 1 Brugada pattern in basal electrocardiography were 2,2 times more likely to have a CE (IC 95% 0,12;40,2). Conclusion In this population, VA induced by PES was not a predictor of CE during the follow-up period, which highlights the difficulty of risk stratification in patients with BrS. New risk-stratification tools are urgently needed to select those patients at higher-risk of SCD, which are candidates for prophylactic ICD implantation.

The Role of Electrophysiological Study in the Risk Stratification of Brugada Syndrome.

Brugada syndrome (BrS) is a complex arrhythmogenic disease associated with an increased risk of sudden cardiac death (SCD). The role of electrophysiological study (EPS) for risk stratification purposes of asymptomatic BrS patients remains still controversial. This study aims to summarize the existing data about the role of electrophysiological study for arrhythmic risk stratification of BrS patients without a prior history of aborted SCD or fatal arrhythmic event. Two independent investigators (G.B. and G.T.) performed a systematic search in the MedLine database and Cochrane library from their inception until April 2022 without any limitations. The reference lists of the relevant research studies as well as the relevant review studies and meta-analyses were manually searched. Nineteen studies were included in the final analysis. The included studies enrolled 6218 BrS patients (mean age: 46.9 years old, males: 76%) while 4265 (68.6%) patients underwent an EPS. The quantitative synthesis showed that a positive EPS study was significantly associated with arrhythmic events in BrS patients (RR, 1.74 [1.23-2.45]; P = 0.002; I2 = 63%]. By including the studies that provided data on the association of EPS with arrhythmic events during follow-up in patients without a prior history of aborted SCD or fatal arrhythmic event, the association between positive EPS study and future arrhythmic events remained significant (RR, 1.60 [1.08-2.36]; P = 0.02; I2 = 19%). In conclusion, EPS is a useful invasive tool for the risk stratification of BrS patients and can be used to identify the population of BrS patients who may be candidates for primary prevention of SCD with implantable cardioverter-defibrillator (ICD) implantation.

PO-03-158 PEDIATRIC CARDIAC SCREENING DATA WAREHOUSE: A NATIONAL PUBLIC HEALTH RESOURCE

Cardiac screening of youth for prevention of sudden cardiac death in the young (SCDY) has been debated due to the absence of large population-specific screening data with outcomes. Despite years of screening by US public screening groups (PSG), there is minimal coordination of effort and no standardized methods for real-world data collection. To understand the methods, quality, outcomes, and best practices of youth screening, the Cardiac Safety Research Consortium Pediatric Cardiology Working Group, in collaboration with FDA and PSGs, developed and enabled a scalable system to collect a uniform pediatric cardiac screening dataset including digital ECGs and post-screening electronic follow-up data. Front end data collection (figure) was developed to include use of a universal unique ID system to align paper/digital collection of health and ECG data. PSGs use secure data transfer portals for digital ECG data upload for conversion to device-agnostic standardized FDA format to store in the national pediatric cardiac screening data warehouse. Follow-up data are obtained at designated post-screening intervals (one week, one and 3 months for pilot study) using initial text message contact followed by electronic consent (REDCap) and answering online health surveys. Fourteen PSGs in ten states participated in the pilot study. PSG warehouse data include 33840 retrospective ECG datasets collected from 2010 to 2021 containing limited screened history/symptoms but demographics similar to US census as follows: Age 13-30y, Male/Female 57/43%, Asian 6%, Black 19%, Native American <1%, Pacific Islander <1%, White 68%, Other 4%; Hispanic/Non-Hispanic 27%/79%. Individual PSG site demographics reflected local populations. Prospective data collection since 2021 include >4000 uniform screening datasets (age, sex, race, ethnicity, ht, wt, screening H&P, COVID history, medications, digital ECG with results, screening outcome, and, if applicable, ECHO results). Follow up participation allowing initial cellular contact was high (avg 73%, range 51-91%/screening). Establishment of a national pediatric cardiac data warehouse enables large-scale aggregation of pediatric cardiac screening information to address deficits in the understanding and prevention of SCDY. This large real-world dataset will help establish normative data for pediatric ECGs which can facilitate development of new diagnostic tools such as machine learning and support pediatric drug and device development.