Previous Syncope Research Articles

Triggers, Risk Factors, and the Prevalence of Syncope Among Domestic Hajj Pilgrims, 2023: A Cross-Sectional Study.

Syncope and other transient loss of consciousness episodes in crowded and unfamiliar environments may lead to major health hazards. Despite numerous publications, data on syncope among Hajj pilgrims in Makkah is lacking. To identify the triggers, risk factors, and prevalence of syncope and other transient loss of consciousness episodes among domestic pilgrims. This cross-sectional study included a convenient sample of domestic pilgrims who performed Hajj in July 2023 using an online Google Forms questionnaire (Alphabet Inc., Mountain View, CA). Out of388 participants, 69 (18.1%) reported a history of syncope during the Hajj pilgrimage. Among these, 57 (82.6%) reported complete loss of consciousness, and 56 (81.2%) noted warning symptoms preceding the episode. The syncopal attack occurred once in 49 respondents (71%). Several triggers for syncope were identified, withsudden standing from a sitting position being the most prevalent (100%). Additional co-triggers were crowding (n=43; 62.3%), stressful conditions (n=30; 43.2%), prolonged standing (n=21; 30.4%), and walking (n=11; 15.9%). Traumatic injuries were reported in 33 (47.8%) as a result of syncope. Standing for long periods of time on the day of Arafat (Arafat standing) emerged as the most common triggering situation (n=48; 69.6%). There were multiple medical factors contributing tosyncopal episodes; the most common medical explanations were heat exhaustion (n=48; 69.6%), dehydration (n=24; 34.8%), over-exertion (n=48; 69.6%), low blood sugar (n=10; 14.5%), and low blood pressure (n=17; 24.6%). Significant predictors were the presence of cardiac disease (odd ratio (OR) 7.6, 95% confidence interval (CI) 2.71-21.45, p<0.001), anemia (OR 2.5, 95% CI 1.01-6.09, p=0.049), previous syncope (OR 2.5, 95% CI 1.02-6.27, p=0.049, and family history of syncope (OR 10.1, 95% CI 2.08-49.32, p=0.004). Syncope during the domestic Hajj pilgrimage is frequent, especially on the day of Arafat, and carries the risk of traumatic injury. People with previous episodes of syncope and comorbidities, especially cardiac patients and those who have a family history of syncope, are particularly prone to this risk. Healthcare should focus on at-riskpatients, particularly on critical pilgrimage days, and increase pilgrims' awareness about triggers of syncope including sudden and prolonged standing, exertion, and heat exposure.

Evolution of the ECG in idiopathic ventricular fibrillation survivors: results from a single-centre UK registry

Abstract Background Idiopathic ventricular fibrillation (VF) is a diagnosis of exclusion in subjects with an unexplained cardiac arrest and no evidence of overt structural or electrical cardiac abnormalities (1). It can be associated with an early repolarisation pattern (ERP)(2). Data on the evolution of the ECG in this population are lacking. Purpose To compare the baseline ECG characteristic of idiopathic VF survivors and age and gender matched controls, and investigate if the presence of an ERP at ECG is a predictor of risk. Methods Forty-nine subjects with idiopathic VF evaluated in our tertiary centre from 1997 to 2022, and followed-up for at least 3 months were included in this study. The first representative ECG available after cardiac arrest was evaluated and compared with that of an age and gender matched control with no symptoms, family history of sudden cardiac death and normal cardiac tests; moreover, comparison was made with a follow-up ECG off antiarrhythmic medications (quinidine, amiodarone and verapamil). Medical notes were reviewed to investigate the presence of events at f-up (SCD/appropriate ICD shock). Results The mean age at presentation was 33±7 years; 63% of patients were males, and 16% had previous syncope. Twelve cases (24%) and 6 controls (12%) showed ERP on the resting ECG (P=NS). Only resting heart rate (HR) and QRS duration differed between the two groups (Table 1). Follow-up ECGs in 46 idiopathic VF survivors indicated that resting HR, QRS axis and QTc values were significantly different compared to the baseline ECG. In addition, 4 subjects with ERP at baseline did not exhibit it on the most recent ECG, and 6 subjects without ERP at baseline showed it on the most recent ECG. Over a median follow-up of 3.3 years (IQR 6), 13 subjects experienced appropriate ICD shocks. Kaplan-Meyer survival estimates showed no differences in events between subjects showing ERP or not (log rank p=0.092). Conclusions Subjects with idiopathic VF show baseline ECGs similar to those of age and gender matched healthy controls from the general population. ECG parameters tend to change only slightly over long-term follow up. The ERP in idiopathic VF survivors is dynamic and thus its relationship with events may be underestimated.Table 1 Table 2

Non-invasive cardiac activation mapping and identification of severity of epicardial substrate in Brugada Syndrome: a case report

IntroductionIt has recently been shown that electrocardiographic imaging (ECGi) can be employed in individuals undergoing an ajmaline test who have Brugada Syndrome (BrS), to evaluate the extent of substrate-involved arrhythmia in the right ventricular overflow tract (RVOT). For the first time, we stratify the risk of sudden cardiac death (SCD) in BrS during ajmaline testing using the dST-Tiso interval (a robust predictor of the inducibility of ventricular arrhythmias (VAs) in the presence of drug-induced BrS type-1 pattern) in combination with ECGi technology.Case presentationWe studied a 48-year-old man with BrS ECG type-2 pattern and presence of J-wave without a family history of SCD but with a previous syncope. Transthoracic echocardiography and cardiac magnetic resonance imaging were performed, showing normal results. The ECG was performed to assess the novel ECG marker “dST-Tiso interval.” The 3D epicardial mapping of the RVOT surface was performed with the support of a non-contact cardiac mapping system in sinus rhythm during ajmaline infusion. The examination of the propagation map unveiled the presence of multiple conduction blocks in this pathologic epicardial region, and the conduction blocks were identified within the central part and/or near the boundary separating the normal and slow conduction areas.ConclusionThe dST-Tiso interval, which lies between the onset and termination of the coved ST-segment elevation and serves as a robust predictor of VA inducibility in cases of drug-induced BrS type-1 pattern, was utilized in conjunction with ECGi technology (employed for the non-invasive confirmation and identification of the pathological substrate area). This combined approach was applied to stratify the risk of SCD in BrS during ajmaline testing, alongside clinical scores.

Arrhythmic risk stratification of filamin C truncating variants carriers

Abstract Background Truncating variants in Filamin C (FLNCtv) are a rare cause of cardiomyopathy with heterogeneous phenotypic presentation and high incidence of life-threatening ventricular arrhythmias, including sudden cardiac death (SCD). Nevertheless, there is a residual gap in the definition of solid risk markers for the stratification of arrhythmic risk and the significance of conventional predictors (i.e. left ventricular ejection fraction [LVEF]) remains extremely controversial. Purpose The aim of this study was to analyze the risk profile and to identify the factors associated with increased risk of life-threatening arrhythmias in an international multicenter cohort of FLNCtv carriers. Methods Patients were retrospectively collected from 19 international tertiary care centers for genetic cardiomyopathies. Primary endpoint was SCD/major ventricular arrhythmias (MVA, i.e. sustained ventricular tachycardia and appropriate implantable cardioverter defibrillator [ICD] shocks). Multivariate Cox regression analysis was performed to identify the predictors of SCD/MVA, taking into account non-sudden cardiac death/heart transplant/destination left ventricle assist device as competing event and including family clusters in the model as clustering factor. Results Among the 326 included carriers (median age 45 years, IQR 33-57; 51% males), 120 (37%) were probands. 100 (31%) carriers had no clinical signs of overt disease; for the others, phenotypic presentation was heterogeneous (36% dilated cardiomyopathy, 17% arrhythmogenic left dominant cardiomyopathy, 4% arrhythmogenic right or biventricular cardiomyopathy, 11% minor phenotype). Median LVEF was 51% (IQR 35%-59%, 41% had LVEF&amp;lt;50%), 16% had right ventricle dysfunction. During a median follow-up of 32 months (IQR 8-63), 60 carriers (18%) experienced SCD/MVA (65% probands, 97% with overt disease, median age at event 48 years, IQR 38-64, min-max 18-78). Among variables associated with the risk of SCD/MVA at univariable analysis, male sex, previous syncope and non-sustained ventricular tachycardia maintained a significant association with the primary outcome at multivariable analysis (Table), whereas there was no significant association between LVEF and the risk of SCD/MVA neither as a continuous nor categorical (i.e. LVEF&amp;lt;50%) variable. In the subgroup of 175 patients with available cardiac magnetic resonance, 57% had late gadolinium enhancement with no significant association with the outcome. Conclusions In the largest worldwide cohort of FLNCtv carriers the high risk of SCD/MVA was confirmed. Three important factors emerged to be associated with higher arrhythmic risk and should be considered for decisions on ICD implantation. Remarkably, LVEF was not significantly associated with SCD/MVA risk. The higher risk observed in males compared with females advocates for prompt investigations on the influence of sex-related factors on the disease expression in genetic cardiomyopathies.

Syncope in Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement.

No data exist on the clinical and prognostic significance of syncope in patients undergoing transcatheter aortic valve replacement (TAVR) for severe aortic stenosis. A total of 1705 consecutive patients with severe aortic stenosis undergoing TAVR in a tertiary university centre between 2007 and 2021 were included and classified according to the presence of syncope before the TAVR procedure. Baseline, procedural, and follow-up data were collected prospectively in a dedicated database. A total of 115 patients (7%) presented with syncope before the TAVR procedure. Of these, 15 patients (13%) showed arrhythmic episodes as the probable cause of the syncope, and all of them had pacemakers implanted at a median of 13 (6 to 53) days before the TAVR procedure. Patients with syncope were older (82 ± 8 years vs 80 ± 8 years, P= 0.001) and had a higher rate of pacemaker implantation before the TAVR procedure (27% vs 14%, P < 0.001), with no differences between groups regarding the severity of aortic stenosis (transvalvular gradient, valve area). There were no differences between groups in 30-day (adjusted hazard ratio [HR], 1.28; 95% confidence interval [CI], 0.46-3.60) and 1-year (adjusted HR, 0.71; 95% CI, 0.0.35-1.45) mortality following TAVR. Syncope was not associated with a more advanced valvular disease and had no significant prognostic impact on patients undergoing TAVR. However, arrhythmias and conduction-system disturbances were more common in patients with previous syncope and might play a relevant role in the pathogenesis of syncope in patients with aortic stenosis.

Septal Microsphere Embolization in Hypertrophic Obstructive Cardiomyopathy

Alcohol septal ablation is an established treatment for selected patients with hypertrophic cardiomyopathy and left ventricular outflow tract obstruction (LVOT). The safety and efficacy of septal microsphere embolization (SME) have not been studied. We conducted a retrospective analysis of SME procedures performed at our center from 2006 to 2021 using 75-µm microspheres. The primary end point was LVOT gradient reduction. Secondary outcomes included periprocedural mortality, conduction disturbances, access site complications, and duration of hospitalization. The population comprised 76 patients (median age 61years, men 43%). Dyspnea New York Heart Association ≥III was present in 65 patients (86%); ventricular tachycardia and previous syncope were described in 4% and 18%, respectively. Median duration of hospitalization was 13days, and the time to first follow-up was 4months. SME resulted in a significant reduction at rest (41 vs 12mm Hg, mean Δ PG=-71%, p <0.001) and provoked LVOT gradients (94 vs 29mm Hg, mean Δ PG=-75%, p <0.001). Periprocedural death occurred in 1 patient (1%) who underwent SME after transcatheter aortic valve replacement. Complete atrioventricular block was observed in 5 patients (7%). Left bundle branch block was diagnosed in 1 case (1%) and right bundle branch block in 3 (4%). Access site complications were observed in 4 patients (5%). In conclusion, SME is a safe and effective alternative to alcohol septal ablation. The potential advantages of microspheres are still to be investigated in prospective studies.

Cardiac defibrillator implantation in patients with syncope and inducible ventricular arrhythmia: insights from the German DEVICE registry

Abstract Funding Acknowledgements Type of funding sources: None. Background Programmed ventricular stimulation may be considered for risk stratification of sudden cardiac death. The history of syncope is an independent predictor for appropriate device discharge and sudden cardiac death, but data remain sparse among different populations. Purpose The aim of this study was to assess the prognostic value of previous syncope and inducible ventricular arrhythmia (VA) during programmed stimulation in patients undergoing defibrillator implantation. Methods Among 4,196 patients enrolled in the prospective, multi-centre German DEVICE Registry undergoing defibrillator implantation, patients with syncope and inducible VA (n=285, 6.8%) vs. those with a secondary preventive indication (n=1,885, 45.2%) serving as a control group were studied. In an additional analysis of patients with inducible VA, those with vs. without (n=86, 2.1%) previous syncope were compared. Results Patients with syncope and inducible VA (64.9±14.4 years, 81.1% male) presented less often with congestive heart failure (15.1% vs. 29.1%; P&amp;lt;0.001) and any underlying structural heart disease (84.9% vs. 89.3%; P=0.030) with a higher left ventricular ejection fraction (43.7±14.2% vs. 38.1±14.2%; P&amp;lt;0.001) than patients with a secondary preventive indication (65.0±13.8 years, 81.0% male). Whereas dilated cardiomyopathy (16.8% vs. 23.8%; P=0.009) was less common in patients with syncope and inducible VA, hypertrophic cardiomyopathy (5.6% vs. 2.8%; P=0.010) and Brugada syndrome (2.1% vs. 0.3%; P&amp;lt;0.001) were found more frequently. Device implantation was performed more often urgently in patients with syncope and inducible VA (46.4% vs. 22.5%; P=0.005). During 1 year of follow-up, mortality (5.1% vs. 8.9%; P=0.036) and the rate of major adverse cardiac or cerebrovascular events (5.8% vs. 10.0%; P=0.027) were lower in patients with previous syncope and inducible VA compared to patients with a secondary preventive indication. Among patients with inducible VA, post-procedural adverse events including rehospitalization (27.6% vs. 21.7%; P=0.37), defibrillator shocks (16.0% vs. 15.0%; P=0.85) and recurrent syncope (3.0% vs. 0%; P=0.32) did not differ between those with vs. without syncope. Conclusions Patients with a history of syncope and inducible VA present less frequently with most cardiac comorbidities resulting in better outcomes following defibrillator implantation than patients with a secondary preventive indication. Nevertheless, patients with inducible VA experience a relevant number of post-procedural adverse events not differing between those with vs. without syncope, which underlines the importance of VA inducibility, potentially irrespective of the history of syncope.

Late potentials assessment - an useful tool for Brugada Syndrome risk stratification

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Brugada syndrome (BrS) is a channelopathy confining an increased risk of sudden cardiac death (SCD). Asymptomatic patients (pts) management remains challenging enhancing the necessity for additionally stratification tools. Purpose To evaluate the role of the non-invasive assessment of late potentials (LP) based on SA-ECG as stratification tools in a BrS cohort. Methods Prospective, observational single-center study of pts with BrS with the following criteria (1) Type 1 Brugada ECG pattern, either spontaneous or drug induced; (2) SA-ECG performed before anti-arrhythmic treatment; (3) minimum follow up duration of 12 months. LPs were evaluated by SA-ECG with determination of the total filtered QRS duration (fQRS); root mean square voltage of the 40ms terminal portion of the QRS (RMS40) and duration of the low amplitude electric potential component of the terminal portion of the QRS (LAS40) in conventional and modified right precordial leads. Malignant arrhythmic events (MAEs) were defined as a composite event of SCD or appropriate ICD shocks. Association of relevant risk factors and MAE was conducted with Univariate Cox regression analysis, as well as SA-ECG evaluated as a continuous and categorical divided on standard cut-offs (fQRS &amp;gt;114ms, RMS40&amp;lt;20µV, LAS40&amp;gt;38ms). A risk score for predicting MAE was computed incorporating the significant LPs variables. Results A total of 106 pts fulfilled the inclusion criteria (mean age: 48 ± 12 years, 67.9% male), 52 (49.1%) with type 1 spontaneous pattern. The majority were asymptomatic at baseline (81.1%) while 13 presented with syncope and 3 with polymorphic VT/cardiac arrest. A total of 10 (7.1%) pts MAEs were documented during a mean 4.7 years - 4 with SCD and 6 with appropriate ICD shocks. Clinical presentation with a polymorphic VT/cardiac arrest (p &amp;lt;0.001) and LP evaluated on SA-ECG were significant predictors of MAE on univariate analysis, except for RMS40 on conventional leads. Neither of the common risk factors (male gender, spontaneous type 1 pattern at baseline, previous syncope or the presence of a pathogenic SCN5A mutation) were predictors of MAE during follow-up– figure 1. Positive LPs defined by standard cut-offs, in all variables and leads, were significantly associated with an increased risk of MAE during follow-up – figure 2. A LP score was computed incorporating the standard cut-offs on conventional leads. The presence of 2 and 3 positive LP represented an additionally 4.7-fold increased risk of MAE during follow-up (HR 4.693, 95% CI 1.506-14.624, p = 0.008) – figure 2. Conclusion LPs based on noninvasive assessment SAECG represent an useful prognostic stratification tool in BrS. A LP score based on standard cut-offs identified a subset of pts at a higher risk of events and who may deserve individualized preventive strategies.

Abstract 11307: Longer Outflow Tract Conduction Time by Magnetocardiography as a Novel Non-Invasive Maker for Predicting Lethal Events in Patients With Brugada Syndrome Without Ventricular Fibrillation

Introduction: Many of the Brugada syndrome (BrS) patients have no symptom or only syncope without ventricular fibrillation (VF)/sudden cardiac death (SCD), thus to whom we should recommend implantable cardioverter defibrillator (ICD) for primary prevention of SCD is still the biggest concern in the BrS. Here we investigated whether a high spatial resolution magnetocardiography (MCG) could predict lethal events of the BrS without history of VF/SCD. Methods: This study retrospectively enrolled 157 BrS patients without VF or cardiopulmonary arrest (CPA) (150 male, 42±13 years old, 118 spontaneous and 39 drug-induced type-1 ECG). Outflow tract conduction time (OT-CT) from 2-D current map of MCG was measured in all patients as well as the standard 12-lead ECG and signal-averaged ECG (SAECG). Programmed electrical stimulation (PES) for VF induction was performed in 47 patients. Results: Patients with spontaneous type-1 ECG had longer OT-CT compared with type-2 BrS patients. Na channel blocker, pilsicainide (25-50mg) unmasked type-1 ECG as well as increased OT-CT (54±18 to 127±62 ms; p&lt;0.05), whereas additional isoproterenol (1ug/kg/min) reversed the pilsicainide-induced delayed OT-CT, thus normalized the ST elevation of ECG. During follow-up (mean 72 [6-147] months), 10 (6%) patients suffered VF/CPA, and those had a higher incidence of previous syncope (50% vs. 14.4%, p=0.01) and longer baseline OT-CT (83±31ms vs. 55±24ms, p=0.01) compared with event-free patients. Receiver operating curve (ROC) revealed OT-CT=65ms was a cut-off value of VF/CPA (AUC=0.78), whereas, spontaneous type-1 ECG, late potential of SAECG, family history, and VF inducibility by PES were not associated with VF/CPA events during follow-up. Multivariate Cox proportional analysis revealed that previous syncope (HR=1.70, 95%CI:1.01-3.05, p=0.04) and OT-CT≥65ms (HR=1.72, 95%CI=1.16-2.62) were the independent predictor for lethal events in the BrS without VF/CPA. Among asymptomatic BrS patients (n=131), OT-CT≥65ms was also an independent predictor for VF/CPA (HR=1.69, 95%CI=1.04-2.79, p=0.03). Conclusion: Longer OT-CT in the MCG may noninvasively demonstrate substrate of VF in BrS and stratify the risk of lethal events in patients with BrS without history of VF or CPA.

Risk of pacemaker implantation after femur fracture in patients with and without a history syncope: a Danish nationwide registry-based follow-up study.

It has previously been described that fall-associated injuries including fractures are commonly observed among patients with bradyarrhythmia. However, knowledge on the risk of pacemaker implantation after admission due to femur fracture from large population-based epidemiologic data is lacking. Therefore, we investigated the risk of pacemaker implantation following femur fracture in patients with and without a history of previous syncope. All patients with femur fracture between 2005-2017 were identified using the Danish Nationwide Patient Registry. Among these, patients already having a pacemaker were excluded. Primary outcome was one-year risk of pacemaker implantation and secondary outcome was one-year all-cause mortality. Multivariable logistic regression was used to obtain absolute and relative risks of the study endpoint in relation to patients with versus without history of syncope and standardized to the age, sex, selected comorbidity and pharmacotherapy distribution of all patients. Of 93,093 patients with femur fracture, 5508 (5.9%) had a history of syncope within five years. Patients with prior syncope were slightly older (84 vs. 83 years), more often male (33.6% vs. 29.4%), and had more often comorbidities relative to those without history of syncope. All-cause mortality was significantly higher among those with previous history of syncope compared to those without previous syncope (29.9% vs. 28.6%, P = 0.021). The relative mortality risk was 1.05 (95% CI: 1.01-1.09, P = 0.021). A total of 695 (0.8%) patients underwent pacemaker implantation within 5 years following femur fracture, and a significantly higher proportion of patients with syncope had a pacemaker implanted within one year (1.6% vs. 0.7%, P < 0.001; relative risk, 2.01 [95% CI: 1.55-2.46]). In patients with femur fracture, a history of syncope was significantly associated with a higher one-year risk of pacemaker implantation.

PREDICTING THE RISK OF SYNCOPE IN PATIENTS WITH AN INDICATION FOR ANTIHYPERTENSIVE TREATMENT: DEVELOPMENT OF THE STRATIFY-SYNCOPE PREDICTION MODEL

Objective: Syncope is one of the most common side effects associated with antihypertensive medication. In patients at increased of syncope, the additional risk of harm from antihypertensive medication may outweigh the potential benefits of treatment in terms of cardiovascular risk reduction. However, it is unclear how to identify patients at most risk of syncope events. This study aimed to develop a clinical prediction model for risk of hospitalisation or death from syncope. Design and method: This was a cohort study using data from the Clinical Practice Research Datalink (CPRD) in the UK. The electronic health records of patients aged greater than 40, with at least one blood pressure measurement between 130–179 mmHg were included. Outcomes were defined as a syncope event resulting in hospitalisation or death within 10 years of baseline. Predictors of syncope were based on the literature and expert opinion and included patient characteristics, past medical history and prescribed treatment (including antihypertensive prescription). A Fine-Gray model was used to adjust for competing risk of mortality and results are reported as subdistribution hazard ratios (SHR). Results: A total of 1,772,617 patients were eligible for the study, with mean age of 59 and 48% males. Median follow up was 6.2 years with 39898 syncope events (2.3%). The antihypertensive medications most strongly associated with syncope were alpha blockers (SHR: 1.21, 95%CI 1.15 to 1.28) and ACE inhibitors (SHR: 1.19, 95%CI 1.16 to 1.22). Other important predictors included age (Figure 1), male sex, high social deprivation, heavy alcohol consumption, previous syncope, diabetes, dementia, structural cardiac problems, arrhythmias, spinal cord injuries, parkinsonism, cardiopulmonary disease and prescription of antidepressants, antipsychotics and opioids (table 1). Conclusions: This prediction model identified a number of strong predictors of syncope which are routinely available in an individual's electronic health records. The accuracy of this model will examined in a further ∼3,000,000 patients from a different electronic health record database. If it is found to perform well, such a model could be used to provide personalised estimates of an individual's risk of harm from antihypertensive treatment, thus facilitating more informed treatment choices.

Predictors for the detection of arrhythmia requiring pacemaker/ICD implantation-Results from a loop recorder study.

There are few large studies on which factors are associated with the occurrence of arrhythmias. Implantable loop recorders (ILR) are useful in detecting arrhythmia due to prolonged and continuous ECG monitoring. Therefore, the aim of this study is to identify and evaluate clinical characteristics and ECG parameters for predicting arrhythmias requiring pacemaker/ICD implantation by analyzing a study cohort with ILR. This bicentric study comprised a study cohort of 451 patients (mean age 64 ± 16 years, 209 women) receiving ILR implantation between 2011 and 2021. Patients were followed up on a 3 monthly outpatient interval. All arrhythmias with a pacemaker or ICD indication were considered clinically relevant. The primary study endpoint was the detection of clinically relevant arrhythmia. During a follow up of 678 ± 392 days, a clinically relevant arrhythmia was detected in 81 of 451 patients (18%). Multivariate analysis revealed five independent risk factors: coronary artery disease (HR 1.954, CI 1.077-3.546, p=.028), atrial fibrillation (HR 2.253, CI 1.201-4.228, p=.011), previous syncope (HR 6.404, CI 3.202-12.808, p<.001), right bundle branch block (HR 4.370, CI 2.215-8.621, p<.001) and left bundle branch block (HR 2.685, CI 1.116-6.461, p=.028). Our risk model, based on these independent predictors, divided the study cohort into patients with low (2%), intermediate (18%), medium (34%), and high (45%) risk for clinically relevant arrhythmia. By the use of ILR, a clinically relevant arrhythmia has been detected in almost one fifth of the study cohort. In addition, clinical and electrocardiographic parameters were shown to be suitable predictors of clinically relevant arrhythmia.

Syncope in patients with transthyretin amyloid cardiomyopathy: clinical features and outcomes

Background We aimed to describe the clinical characteristics, underlying causes and outcomes of syncope in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). Methods The clinical profile and underlying causes of syncopal episodes were reviewed in a cohort of 128 patients with ATTR-CM enrolled from January-2018 to June-2020 in a prospective multicentre registry in 7 hospitals of Galicia (Spain). After enrollment, patients were followed during a median period of 520 days. The effect of syncope on all-cause mortality was assessed by means of multivariate Cox´s regression. Results : Thirty (23.4%) patients had a history of previous syncope as a clinical antecedent before being enrolled in the prospective phase of the registry, and 4 (3.1%) experienced a first episode of syncope thereafter. The estimated incidence density rate of syncope during the prospective follow-up period after registry enrolment was 71.9 episodes per 1000 patients-year (95% Confidence Interval (CI) 32.8–111.1). The estimated overall prevalence of syncope was 26.6% (95% CI 18.9%–34.2%). Cardiac arrhythmias (n=11, 32.3%), structural diseases of the heart or great vessels (n=5, 14.7%), a neurally mediated reflex (n=6, 17.6%), and orthostatic hypotension (n=4, 11.8%) were identified as probable underlying causes of syncope; in 8 (23.6%) patients, syncope remained unexplained. Patients with syncope had increased non-adjusted all-cause mortality than patients without it (univariate hazard-ratio 3.37; 95% CI 1.43–7.94). When other independent predictors of survival were added to the survival model, this association was no longer statistically significant (multivariate hazard-ratio 1.81, 95% CI 0.67–4.84). Conclusions Syncope is frequent in patients with ATTR-CM. This study could not demonstrate an independent association between syncope and mortality in those individuals.

Evaluation of the Feasibility and Efficacy of a Novel Device for Screening Silent Atrial Fibrillation (MYBEAT Trial).

myBeat is a novel cutaneous patch device that continuously records electrocardiography and automatically detects atrial fibrillation (AF) by using a new algorithm based on RR intervals. We aimed to test the diagnostic ability of this novel device for screening silent AF in asymptomatic patients.Methods and Results:A multicenter randomized prospective clinical study was performed. To be eligible for inclusion in the study, patients had to be ≥65 years of age and have ≥1 of the following risk factors: hypertension, diabetes, heart failure, ischemic heart disease, stroke, and transient ischemic attack. Patients with prior AF, an implantable pacemaker, and previous palpitation or syncope were excluded. The 300 participants were divided into 2 groups, those using myBeat (n=150) or those undergoing 24-h Holter monitoring (control group; n=150), for AF screening. The rate of AF detection was significantly higher in the myBeat than control group (16 [10.7%] vs. 7 [4.7%], respectively; P=0.04). Multivariable logistic regression analysis revealed that prior heart failure was an independent predictor of silent AF (odds ratio 12.07; 95% confidence interval 1.67-86.27; P=0.01). A 7.7-fold difference in silent AF was found between subjects with CHA2DS2-VASc scores of 1 point and those with scores ≥4 points. The novel patch device using an original algorithm was beneficial for screening of silent AF.

201 Clinical presentation profiles and natural history of cardiac amyloidosis: long-term monocentric analysis (1990–2020)

Abstract Aims Cardiac Amyloidosis (CA) is considered a rare condition comprising different entities. Epidemiological data are limited and the natural history of disease is largely unknown. Understanding the clinical profiles at presentation, the impact of novel diagnostic strategies and the prognostic predictors at baseline will improve patients’ clinical management. We aimed to examine the epidemiology and natural history of CA in the last 30 years at a tertiary referral centre for amyloidosis. Methods and results Data of patients included in the prospective ‘Cardiac Amyloidosis Registry’ of Trieste from January 1990 to December 2020 were extracted from an electronical database and analysed. The diagnosis of CA was made in presence of (a) amyloid deposition found at endomyocardial biopsy (EMB), or (b) high grade cardiac uptake at bisphosphonate scintigraphy in absence of monoclonal components. Cardiological data of patients included (i) clinical examination, (ii) electrocardiogram (ECG), (iii) echocardiography and (iv) medications. The primary outcome measure was all-cause mortality. The secondary outcome measure was cardiac death. Of the 143 patients with CA included in this analysis, 77 (54%) were diagnosed before 2016 (historical cohort) and 66 (46%) ≥2016 (contemporary cohort). Light chain (AL) amyloidosis and transthyretin (ATTR) amyloidosis accounted for 49% and 38%, respectively, of all CA patients. CA of unknown aetiology accounted for 13% of cases. CA was diagnosed by EMB in 98 (69%) patients and by cardiac scintigraphy with bone tracers in 45 (31%) patients. Patients in the contemporary cohort (67% ATTR-CA) were diagnosed more frequently by non-invasive approach compared to those in the historical cohort. At a median global Follow-up of 36 months, a more favourable outcome was found in a) patients from the contemporary cohort compared to those from the historical cohort (P &amp;lt; 0.001), b) ATTR- compared to AL-CA (at 18 months of Follow-up 42 (85%) ATTR patients and 32 (60%) AAL patients were alive, P = 0.013), and, (c) patients diagnosed non-invasively by scintigraphy rather than by histology (at 18 months of Follow-up 36 (80%) of patients diagnosed by cardiac scintigraphy and 57 (60%) of those diagnosed by histology were alive, P = 0.001). Of note, while no difference in outcome was found among AL- and ATTR-CA in the historical cohort, ATTR-CA patients had lower all-cause mortality and cardiac death than AL-CA patients in the contemporary cohort. Overall, death for end stage HF was more prevalent in patients with AL- than ATTR-CA (58% vs. 25%, P = 0.002). At univariable analysis, ACE-i and beta blockers (BBs) therapy were associated with a more favorable outcome [HR: 0.38, (0.26–0.60, P &amp;lt; 0.001) and HR: 0.53 (0.33–0.85, P = 0.008), respectively], while experiencing a previous syncope and having low QRS voltages at surface ECG portended a worse overall survival [HR: 2.42 (1.3–4.5, P = 0.006) and HR: 1.94 (1.3–3.0, P = 0.002), respectively]. At multivariate analysis, treatment with ACE-i, BBs, and syncope had independent prognostic value [HR 0.41 (0.23–0.71, P = 0.002); HR 0.50 (0.31–0.82, P = 0.007), and HR: 2.1 (1.0–4.1, P = 0.040); respectively]. Conclusions The epidemiology and natural history of CA has been changing. Over years, ATTR-CA had the most favourable outcome. NYHA functional class, syncope, BBs and ACE-i therapy were useful parameters for prognostic stratification. Further research is needed to investigate if they could be integrated in multiparametric scores for more accurate outcome prediction.

C50. Obstructive hypertrophic cardiomyopathy in young adult man: a case report

Abstract Background Hypertrophic obstructive cardiomyopathy (obstructive HCM) is an autosomal dominant congenital disease characterized by obstruction of the left ventricular outflow tract with asymmetric septal hypertrophy. Obstructive HCM is predispose to the appearance of malignant ventricular arrhythmias, leading to syncope or sudden death. Case Description A 25-years-old male patient came to the hospital with chief complaint intolerance activity and previous syncope, without history of sudden cardiac death in his family member. ECG showed sinus rhytm with left axis deviation and left ventricular hypertrophy. Chest x ray showed cardiomegaly. The echocardiography showed asymmetric septal hypertrophy (septal/posterior wall thickness ratio 1.31), left atrium dilatation (LAVi 94.2 mL/m2), SAM and mild mitral regurgitation, mild aortic regurgitation, hyperdynamic ejection fraction (79%) with lower longitudinal strain values in basal and mid ventricular septal segment, grade I diastolic dysfunction, resting LVOT gradient 19.53 mmHg , provoked LVOT gradient 47.31 mmHg. Discussion Non-invasive treatment was given due to LVOT gradient below 50 mmHg. The patient prescribed diltiazem 100mg once daily and recommended clinical evaluation follow-up every year or any worsening of symptoms. The other family member suggested for familial screening echocardiography.

C50. Obstructive hypertrophic cardiomyopathy in young adult man: a case report

Abstract Background Hypertrophic obstructive cardiomyopathy (obstructive HCM) is an autosomal dominant congenital disease characterized by obstruction of the left ventricular outflow tract with asymmetric septal hypertrophy. Obstructive HCM is predispose to the appearance of malignant ventricular arrhythmias, leading to syncope or sudden death. Case Description A 25-years-old male patient came to the hospital with chief complaint intolerance activity and previous syncope, without history of sudden cardiac death in his family member. ECG showed sinus rhytm with left axis deviation and left ventricular hypertrophy. Chest x ray showed cardiomegaly. The echocardiography showed asymmetric septal hypertrophy (septal/posterior wall thickness ratio 1.31), left atrium dilatation (LAVi 94.2 mL/m2), SAM and mild mitral regurgitation, mild aortic regurgitation, hyperdynamic ejection fraction (79%) with lower longitudinal strain values in basal and mid ventricular septal segment, grade I diastolic dysfunction, resting LVOT gradient 19.53 mmHg , provoked LVOT gradient 47.31 mmHg. Discussion Non-invasive treatment was given due to LVOT gradient below 50 mmHg. The patient prescribed diltiazem 100mg once daily and recommended clinical evaluation follow-up every year or any worsening of symptoms. The other family member suggested for familial screening echocardiography.

Long-Term Prognosis of Febrile Individuals with Right Precordial Coved-Type ST-Segment Elevation Brugada Pattern: A 10-Year Prospective Follow-Up Study.

A febrile state may provoke a Brugada electrocardiogram (ECG) pattern and trigger ventricular tachyarrhythmias in susceptible individuals. However, the prognostic value of fever-induced Brugada ECG pattern remains unclear. We analyzed the clinical and extended long-term follow-up data of consecutive febrile patients with a type 1 Brugada ECG presented to the emergency department. A total of 21 individuals (18 males; mean age, 43.7 ± 18.6 years at diagnosis) were divided into symptomatic (resuscitated cardiac arrest in one, syncope in two) and asymptomatic (18, 86%) groups. Sustained polymorphic ventricular tachycardias were inducible in two patients with previous syncope. All 18 asymptomatic patients had no spontaneous type 1 Brugada ECG recorded at second intercostal space and no family history of sudden death. Among asymptomatic individuals, 4 had a total 12 of repeated non-arrhythmogenic febrile episodes all with recurrent type 1 Brugada ECGs, and none had a ventricular arrhythmic event during 116 ± 19 months of follow-up. In the symptomatic group, two had defibrillator shocks for a new arrhythmic event at 31- and 49 months follow-up, respectively, and one without defibrillator therapy died suddenly at 8 months follow-up. A previous history of aborted sudden death or syncope was significantly associated with adverse outcomes in symptomatic compared with asymptomatic individuals (log-rank p < 0.0001). In conclusion, clinical presentation or history of syncope is the most important parameter in the risk stratification of febrile patients with type 1 Brugada ECG. Asymptomatic individuals with a negative family history of sudden death and without spontaneous type 1 Brugada ECG, have an exceptionally low future risk of arrhythmic events. Careful follow-up with timely and aggressive control of fever is an appropriate management option.

Validación de escalas multiparamétricas de predicción de riesgo de muerte súbita en pacientes con síndrome de Brugada y estudio electrofisiológico

Introduction and objectivesMultiparametric scores have been designed for better risk stratification in Brugada syndrome (BrS). We aimed to validate 3 multiparametric approaches (the Delise score, Sieira score and the Shanghai BrS Score) in a cohort with Brugada syndrome and electrophysiological study (EPS). MethodsWe included patients diagnosed with BrS and previous EPS between 1998 and 2019 in 23 hospitals. C-statistic analysis and Cox proportional hazard regression models were used. ResultsA total of 831 patients were included (mean age, 42.8±13.1; 623 [75%] men; 386 [46.5%] had a type 1 electrocardiogram (ECG) pattern, 677 [81.5%] were asymptomatic, and 319 [38.4%] had an implantable cardioverter-defibrillator). During a follow-up of 10.2±4.7 years, 47 (5.7%) experienced a cardiovascular event. In the global cohort, a type 1 ECG and syncope were predictive of arrhythmic events. All risk scores were significantly associated with events. The discriminatory abilities of the 3 scores were modest (particularly when these scores were evaluated in asymptomatic patients). Evaluation of the Delise and Sieira scores with different numbers of extra stimuli (1 or 2 vs 3) did not substantially improve the event prediction c-index. ConclusionsIn BrS, classic risk factors such as ECG pattern and previous syncope predict arrhythmic events. The predictive capabilities of the EPS are affected by the number of extra stimuli required to induce ventricular arrhythmias. Scores combining clinical risk factors with EPS help to identify the populations at highest risk, although their predictive abilities remain modest in the general BrS population and in asymptomatic patients.

Validation of multiparametric approaches for the prediction of sudden cardiac death in patients with Brugada syndrome and electrophysiological study

Introduction and objectivesMultiparametric scores have been designed for better risk stratification in Brugada syndrome (BrS). We aimed to validate 3 multiparametric approaches (the Delise score, Sieira score and the Shanghai BrS Score) in a cohort with Brugada syndrome and electrophysiological study (EPS). MethodsWe included patients diagnosed with BrS and previous EPS between 1998 and 2019 in 23 hospitals. C-statistic analysis and Cox proportional hazard regression models were used. ResultsA total of 831 patients were included (mean age, 42.8±13.1; 623 [75%] men; 386 [46.5%] had a type 1 electrocardiogram (ECG) pattern, 677 [81.5%] were asymptomatic, and 319 [38.4%] had an implantable cardioverter-defibrillator). During a follow-up of 10.2±4.7 years, 47 (5.7%) experienced a cardiovascular event. In the global cohort, a type 1 ECG and syncope were predictive of arrhythmic events. All risk scores were significantly associated with events. The discriminatory abilities of the 3 scores were modest (particularly when these scores were evaluated in asymptomatic patients). Evaluation of the Delise and Sieira scores with different numbers of extra stimuli (1 or 2 vs 3) did not substantially improve the event prediction c-index. ConclusionsIn BrS, classic risk factors such as ECG pattern and previous syncope predict arrhythmic events. The predictive capabilities of the EPS are affected by the number of extra stimuli required to induce ventricular arrhythmias. Scores combining clinical risk factors with EPS help to identify the populations at highest risk, although their predictive abilities remain modest in the general BrS population and in asymptomatic patients.