History Of Unexplained Syncope Research Articles

Clinical findings and outcomes of Brugada syndrome in women

Abstract Introduction Brugada syndrome (BrS) is a genetic disorder characterized by typical ECG changes and association with spontaneous ventricular tachyarrhythmia (VTA) and sudden death in young patients. BrS has been widely established to be particularly prevalent in men, however less information exists regarding female patients and their long-term risk. Objectives The purpose of this study was to investigate the clinical characteristics and long-term prognosis of women with BrS. Methods This study includes a retrospective analysis of a single-center cohort of patients followed and observed for relevant clinical outcomes. The data collected included demographic data, severity of symptoms (e.g. syncope, VTA), cardioverter-defibrillator logs and occurrence of sudden cardiac death. Results 317 patients were diagnosed with BrS between 1998 and 2023. Among those, 112 (36%) were female. At presentation, 5 patients (4%) were symptomatic with history of survived cardiac arrest and/or documented VTA. 29 (26%) had history of unexplained syncope and 78 (70%) were asymptomatic. The average age at diagnosis was 42.1±15.1 yrs. as opposed to 40.1±14.2 yrs. in men. Females presented less frequently with a type 1 ECG pattern (5% vs 21%; p<0.01), had a trend to a higher rate of family history of sudden cardiac death (31% vs 25%; p=n.s.), and had less sustained VTA during programmed ventricular stimulation (4% vs 19%; p<0.01). Genetic testing was performed in 89 females (79% of the sample) and pathogenic variants were present in 36 (40%) women. An implantable cardioverter defibrillator was inserted in 24 (31%) females for primary prevention. During mean follow-up of 138±72 months, 11 women had cardiovascular events (syncope, VT/VF or death). Syncope was most common and occurred in 8 cases. No VTA were documented in any female patient. In the group of ICD patients, 8 shocks have occurred. None of these were deemed appropriate by medical controls. There were 3 deaths. Two were considered non-arrhythmic due to pulmonary embolism and breast carcinoma. One ICD patient died suddenly during sleep. Unfortunately, no device interrogation data was available. Conclusion Women typically present less symptomatic and demonstrate a reduced incidence of life-threatening arrhythmias during follow-up , often experiencing a frequent occurrence of inappropriate implantable defibrillator therapy. The less frequent prevalence of the BrS ECG pattern in women adds complexity to the diagnostic process. Further studies are still needed to elucidate gender differences for risk stratification of BrS.

Permanent pacemaker implantation in unexplained syncope patients with electrophysiology study-proven atrioventricular node disease

ObjectiveSyncope, whose cause is unknown after an initial assessment, has an uncertain prognosis. It is critical to identify patients at the highest risk who may require a pacemaker and to identify the cause of recurrent syncope to prescribe proper therapy. The aim of this study was to evaluate the effect of permanent pacing on the incidence of syncope in patients with unexplained syncope and electrophysiology study (EPS)-proven atrioventricular (AV) node disease. MethodsThis was an observational study based on a prospective registry of 236 consecutive patients (60.20 ± 18.66 years, 63.1% male, 60.04 ± 9.50 bpm) presenting with recurrent unexplained syncope attacks admitted to our hospital for invasive EPS. The decision to implant a permanent pacemaker was made in all cases by the attending physicians according to the results of the EPS. A total of 135 patients received the antibradycardia pacemaker (ABP), while 101 patients were declined. ResultsThe mean of reported syncope episodes was 1.97 ± 1.10 (or presyncope 2.17 ± 1.50) before they were referred for a combined EP-guided diagnostic and therapeutic approach. Over a mean follow-up of approximately 4 years (49.19 ± 29.58 months), the primary outcome event (syncope) occurred in 31 of 236 patients (13.1%), and 6 of 135 (4.4%) patients in the ABP group as compared to 25 of 101 (24.8%) in the no pacemaker group (p < 0.001). ConclusionAmong patients with a history of unexplained syncope, a set of positivity criteria for the presence of EPS-defined AV node disease identifies a subset of patients who will benefit from permanent pacing.

Risk of incident fractures in individuals hospitalised due to unexplained syncope and orthostatic hypotension

BackgroundImpaired orthostatic blood pressure response and syncope confer a high risk of falls and trauma. The relationship between a history of unexplained syncope and orthostatic hypotension (OH) with subsequent fractures, however, has not been thoroughly examined. In this study, we aimed to investigate the relationship between previous hospital admissions due to unexplained syncope and OH and incident fractures in a middle-aged population.MethodsWe analysed a large population-based prospective cohort of 30,399 middle-aged individuals (age, 57.5 ± 7.6; women, 60.2%). We included individuals hospitalised due to unexplained syncope or OH as the main diagnosis. Multivariable-adjusted Cox regression analysis was applied to assess the impact of unexplained syncope and OH hospitalisations on subsequent incident fractures.ResultsDuring a follow-up period of 17.8 + 6.5 years, 8201 (27%) subjects suffered incident fractures. The mean time from baseline and first admission for syncope (n = 493) or OH (n = 406) was 12.6 ± 4.2 years, and the mean age of the first hospitalisation was 74.6 ± 7.4 years. Individuals with incident fractures were older, more likely to be women, and had lower BMI, higher prevalence of prevalent fractures, and family history of fractures. Multivariable-adjusted Cox regression showed an increased risk of incident fractures following hospitalisations due to unexplained syncope (HR 1.20; 95% CI 1.02–1.40; p = 0.025) and OH (HR 1.42; 95% CI 1.21–1.66; p < 0.001) compared with unaffected individuals.ConclusionsIndividuals hospitalised due to unexplained syncope and orthostatic hypotension have an increased risk of subsequent fractures. Our findings suggest that such individuals should be clinically assessed for their syncope aetiology, with preventative measures aimed at fall and fracture risk assessment and management.

Permanent pacemaker implantation in unexplained syncope patients with electrophysiology study-proven atrioventricular node disease

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction: Syncope, whose cause is unknown after an initial assessment, has an uncertain prognosis. It is critical to identify patients at highest risk who may require a pacemaker and to identify the cause of recurrent syncope to prescribe proper therapy Purpose Aim of this study was to evaluate the effect of permanent pacing on the incidence of syncope in patients with unexplained syncope and electrophysiology study-proven atrioventricular node disease. Methods This was an observational study based on a prospective registry of 236 consecutive patients (60.20 ± 18.66 years, 63.1% male, 60.04 ± 9.50 bpm) presenting with recurrent unexplained syncope attacks admitted to our hospital for invasive electrophysiology study (EPS). Τhe implantation of a permanent antibradycardia pacemaker (ABP) was offered to all patients according to the results of the EPS. 135 patients received the ABP, while 101 denied. Results The mean of reported syncope episodes was 1.97 ± 1.10 (or presyncope 2.17 ± 1.50) before they were referred for a combined EP guided diagnostic and therapeutic approach. Over a mean follow-up of approximately 4 years (49.19 ± 29.58 months), the primary outcome event (syncope) occurred in 31 of 236 patients (13.1%), 6 of 135 (4.4%) in the ABP group as compared to 25 of 101 (24.8%) in the no pacemaker group (p &amp;lt; 0.001). Conclusion Among patients with a history of unexplained syncope, a set of positivity criteria for the presence of EPS defined atrioventricular node disease, identifies a subset of patients who will benefit from permanent pacing.

Permanent pacemaker implantation in unexplained syncope patients with borderline sinus bradycardia and electrophysiology study-proven sinus node disease.

BackgroundSignificant sinus bradycardia (SB) in the context of sinus node dysfunction (SND) has been associated with neurological symptoms. The objective was to evaluate the effect of permanent pacing on the incidence of syncope in patients with rather mild degrees of SB, unexplained syncope, and “positive” invasive electrophysiologic testing.MethodsThis was an observational study based on a prospective registry of 122 consecutive mild SB patients (61.90 ± 18.28 years, 61.5% male, 57.88 ± 7.73 bpm) presenting with recurrent unexplained pre and syncope attacks admitted to our hospital for invasive electrophysiology study (EPS). Τhe implantation of a permanent antibradycardia pacemaker (ABP) was offered to all patients according to the results of the EPS. Eighty patients received the ABP, while 42 denied.ResultsThe mean of reported syncope episodes was 2.23 ± 1.29 (or presyncope 2.36 ± 1.20) in the last 12 months before they were referred for a combined EP guided diagnostic and therapeutic approach. Over a mean follow‐up of approximately 4 years (50.39 ± 32.40 months), the primary outcome event (syncope) occurred in 18 of 122 patients (14.8%), 6 of 80 (7.5%) in the ABP group as compared to 12 of 42 (28.6%) in the no pacemaker group (P = .002).ConclusionsAmong patients with mild degree of SB and a history of unexplained syncope, a set of positivity criteria for the presence of EPS defined SND after differentiating reflex syncope, identifies a subset of patients who will benefit from permanent pacing.

Novel insights on Andersen-Tawil syndrome type 1

Abstract Background Andersen-Tawil Syndrome type 1 (ATS1) in a rare arrhythmogenic disease caused by loss-of-function mutations in the KCNJ2 gene and characterized by ventricular arrhythmias, dysmorphic features and episodes of periodic paralysis. Although the prognosis of ATS1 patients is typically considered benign, definitive outcome data are lacking. Purpose We aimed to: 1) define the risk of life-threatening arrhythmic events (LAEs); 2) identify risk factors for such events; 3) assess the efficacy of anti-arrhythmic drugs in preventing LAEs. Methods We included 118 ATS1 patients from 57 families with confirmed pathogenic or likely pathogenic KCNJ2 mutations. Clinical and genetical data were acquired by investigators from 23 centers in 9 countries. Results Baseline characteristics of the population are presented in the Table. Over a follow-up of 6.2 years, 17/118 (14%) patients experienced a first LAE, with a 5-year cumulative probability of 7.9% (Figure). Cox multivariable analysis demonstrated that a previous history of syncope (HR 4.5, p=0.02), the documentation of sustained VT (HR 9.3, p=0.001) and the administration of amiodarone (HR 268, p&amp;lt;0.001) were associated with an increased risk of LAE. The baseline rate of LAE was not reduced by beta-blockers alone (1.37 per 100 py; p=1), or in combination with class Ic antiarrhythmic drugs (1.46 per 100 py, p=1). Conclusions Our data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope, and documentation of sustained ventricular tachycardia are independently associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in ATS1 patients. ATS1: Diagnosis, Outcome, Risk Factors Funding Acknowledgement Type of funding source: Public grant(s) – EU funding. Main funding source(s): ERN Guard-Heart European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart

Natural History and Risk Stratification in Andersen-Tawil Syndrome Type 1

BackgroundAndersen-Tawil Syndrome type 1 (ATS1) is a rare arrhythmogenic disorder, caused by loss-of-function mutations in the KCNJ2 gene. We present here the largest cohort of patients with ATS1 with outcome data reported. ObjectivesThis study sought to define the risk of life-threatening arrhythmic events (LAE), identify predictors of such events, and define the efficacy of antiarrhythmic therapy in patients with ATS1. MethodsClinical and genetic data from consecutive patients with ATS1 from 23 centers were entered in a database implemented at ICS Maugeri in Pavia, Italy, and pooled for analysis. ResultsWe enrolled 118 patients with ATS1 from 57 families (age 23 ± 17 years at enrollment). Over a median follow-up of 6.2 years (interquartile range: 2.7 to 16.5 years), 17 patients experienced a first LAE, with a cumulative probability of 7.9% at 5 years. An increased risk of LAE was associated with a history of syncope (hazard ratio [HR]: 4.54; p = 0.02), with the documentation of sustained ventricular tachycardia (HR 9.34; p = 0.001) and with the administration of amiodarone (HR: 268; p < 0.001). The rate of LAE without therapy (1.24 per 100 person-years [py]) was not reduced by beta-blockers alone (1.37 per 100 py; p = 1.00), or in combination with Class Ic antiarrhythmic drugs (1.46 per 100 py, p = 1.00). ConclusionsOur data demonstrate that the clinical course of patients with ATS1 is characterized by a high rate of LAE. A history of unexplained syncope or of documented sustained ventricular tachycardia is associated with a higher risk of LAE. Amiodarone is proarrhythmic and should be avoided in patients with ATS1.

Predictive factors for pacemaker implantation in patients receiving an implantable loop recorder for syncope remained unexplained after an extensive cardiac and neurological workup

Several previous implantable loop recorder (ILR) studies have shown bradyarrhythmic events requiring a pacemaker implantation in a significant proportion of patients with unexplained syncope (US). The aim of this observational, two-centre, study was to identify the predictive factors for pacemaker implantation in a population of patients receiving an ILR for US with suspected arrhythmic aetiology. Fifty-six patients (mean age 68 years, 61% male) with a history of US and negative cardiac and neurological workup, who underwent ILR implantation, were enrolled. After the implantation, a follow-up visit was undertaken after symptomatic events or every 3 months in asymptomatic subjects. The end-point of the study was the detection of a bradyarrhythmia (with or without a syncopal recurrence) requiring pacemaker implantation. After a median ILR observation of 22 months, a clinically significant bradyarrhythmia was detected in 11 patients (20%), of which 9 cases related to syncopal relapses. In the multivariable analysis, three independent predictive factors for pacemaker implantation were identified: an age >75 years (odd ratio [OR]: 29.9; p=0.035); a history of trauma secondary to syncope (OR: 26.8; p=0.039); and the detection of periods of asymptomatic bradycardia, not sufficient to explain the mechanism of syncope, during conventional ECG monitoring (through 24 h Holter or in hospital telemetry), performed before ILR implantation (OR: 24.7; p=0.045). An advanced age, a history of trauma secondary to syncope, and the detection of periods of asymptomatic bradycardia during conventional ECG monitoring were independent predictive factors for bradyarrhythmias requiring pacemaker implantation in patients receiving an ILR for US.

Head-up tilt testing for diagnosing vasovagal syncope: A meta-analysis

We read with great interest the article by Forleo et al. regarding the accuracy of head-up tilt testing in the diagnosis of vasovagal syncope [1]. We do support the authors' attempt of obtaining the best evidence by performing a systematic review and a meta-analysis on a still controversial argument. However, we wonder if a simple systematic review wouldn't have been more appropriate. Indeed, since case–control studies tend to overestimate sensitivity and specificity [2], combining their results in a meta-analysis could lead to have excessive confidence in the accuracy of a diagnostic test. Moreover, the patients considered as cases and as controls do not allow to infer about the sensitivity and specificity of head-up tilt testing in the diagnosis of vasovagal syncope, because the former were subjects with a history of unexplained syncope, whereas the latter were asymptomatic subjects. Wouldn't have been more appropriate to consider, as cases, subjects diagnosed as having a vasovagal syncope and, as controls, subjects with syncope of other etiology? Besides, shouldn't the diagnosis of vasovagal syncope at clinical follow-up be considered as the reference standard? Therefore, although the systematic review of the available evidence is very interesting, its data may lead to an excessive and groundless reliability of the results, thus overestimating the diagnostic accuracy of head-up tilt testing. We believe that the most appropriate conclusion should be that good quality studies for determining the diagnostic accuracy of head-up tilt testing in vasovagal syncope are still lacking.

A case of Brugada syndrome patient undertaken total intravenous anesthesia with remifentanil

A case of Brugada syndrome patient undertaken total intravenous anesthesia with remifentanil

Characterization of early repolarization during ajmaline provocation and exercise tolerance testing

Early repolarization (ER) in the inferior electrocardiogram leads is associated with idiopathic ventricular fibrillation, but the majority of subjects with ER have a benign prognosis. At present, there are no risk stratifiers for asymptomatic ER. To examine the response to ajmaline provocation and exercise in potentially high-risk subjects with ER and without a definitive cardiac diagnosis. Electrocardiographic data were reviewed for ER at baseline and during ajmaline and exercise testing in 229 potentially high-risk patients (mean age 37.7±14.9 years; 55.9% men). ER was defined as J-point elevation in ≥2 consecutive leads and stratified by type, territory, J-point height, and ST-segment morphology. Baseline ER was present in 26 (11.4%; 19 men) patients. During ajmaline provocation and exercise, there were no new ER changes. ER with rapidly ascending ST-segment and lateral ER consistently diminished. There were 7 patients with persistent ER during ajmaline and/or exercise. They were all men with inferior or inferolateral ER and horizontal/descending ST segment. Those with persistent ER during exercise were more likely to have a history of unexplained syncope than those in whom ER changes diminished (P<.01). Subtle nondiagnostic structural abnormalities were demonstrated in 3 of these patients. ER with horizontal/descending ST-segment morphology in the inferior or inferolateral leads that persists during exercise is more common in patients with prior unexplained syncope and may identify patients at higher risk of arrhythmic events. ER that persists during ajmaline provocation and/or exercise may reflect underlying subtle structural abnormalities and should prompt further investigation.

Revisiting risk stratification in hypertrophic cardiomyopathy: Do we need to start from scratch?

t t i b t c t While the majority of those with hypertrophic cardiomyopathy (HCM) will remain asymptomatic, a significant subset will suffer the devastating complication of sudden cardiac death (SCD). It is difficult to disagree with the notion that implantable cardioverter-defibrillator (ICD) therapy is warranted for secondary prevention after cardiac arrest or sustained ventricular tachyarrhythmia in HCM, but the implantation of an ICD for primary prevention is more controversial as a result of competing risks. Rigorous prediction of the risk of SCD remains the major challenge for those caring for individuals or families with HCM. A number of factors have been associated with the risk of SCD in observational studies and adopted for clinical use through consensus. These include (1) family history of CM-related SCD, (2) history of unexplained syncope, (3) eft ventricular wall thickness 30 mm, (4) nonsustained entricular tachycardia on ambulatory Holter electrocardioram, and (5) a hypotensive or attenuated blood pressure esponse to exercise. These risk markers have a reasonable negative predictive value (approximately 90%) in typical probands, but their positive predictive value is relatively low (in the range of 15%–20%) even in typical clinical cohorts. The majority of patients with HCM will fall into an intermediate group where the benefit of ICD remains unclear. Of note, appropriate ICD intervention rates do not iffer among patients with 1, 2, or 3 traditional risk factors, uggesting substantial confounding of current prediction odels. In sum, the present risk stratification algorithm offers no prospective quantitative estimate of SCD risk and is of little utility in the very subset of patients who would likely benefit most from ICD implantation. The failure of current risk stratification algorithms is firmly rooted in the fundamental biology of HCM. Studies of HCM risk to date have not included any rigorous data on relatedness. Probands, who have presented clinically, are not discriminated from asymptomatic family members detected on screening. The mode of entry to individual studies is often unclear, leading to the selection of individuals in

Independent role of reduced arterial baroreflex sensitivity during head-up tilt testing in predicting vasovagal syncope recurrence

The involvement of arterial baroreflex function in the pathophysiology of vasovagal syncope (VVS) is controversial, and there are no published data supporting its clinical usefulness. The aim of this study was to evaluate the role of arterial baroreflex sensitivity (BRS) at baseline and during head-up tilt testing (HUT) in predicting the recurrence of VVS. The study involved otherwise healthy patients with a history of unexplained syncope who underwent diagnostic HUT by being tilted to 70 degrees after 10 min supine rest; the test was potentiated by the administration of 300 microg of nitroglycerine (NTG) after 20 min. Beat-to-beat heart rate and systolic blood pressure were continuously recorded, and the sequence method was used to measure arterial baroreflex control of heart rate. The 190 enrolled patients were followed up for 18 +/- 6 months, during which 34 experienced a total of 90 episodes of syncope recurrence. In a stepwise multivariate analysis, female gender [hazard ratio (HR): 2.74; P = 0.008], the presence of >or=3 syncope events before HUT (HR: 3.36; P = 0.004), and BRS below median value after the start of HUT or after the administration of NTG (HR: 3.79; P = 0.006) were significantly and independently associated with the recurrence of syncope. Moreover, when a BRS value of less than the median was added to the other independent factors in a stepwise model, a significant increase in discrimination (C-index: 0.77) and model fitting (P = 0.001) was observed. Reduced BRS during HUT has independent and incremental value in predicting the recurrence of syncope, thus supporting its potential usefulness in the clinical management of patients.

The quest for perfection: the contribution of the electrocardiogram to the prevention of sudden death in hypertrophic cardiomyopathy

Haghjoo et al. 1 report a retrospective electrocardiographic study investigating the prognostic value of the 12-lead electrocardiogram (ECG) in 173 patients with hypertrophic cardiomyopathy (HCM). During a follow-up period of 50 months, 6% of the study group experienced the composite endpoint of sudden cardiac death (SCD), aborted SCD, or appropriate internal cardioverter defibrillator (ICD) shock. Univariable analysis confirmed the association of conventional risk markers such as non-sustained ventricular tachycardia, severe left ventricular (LV) hypertrophy, and a history of unexplained syncope with the composite endpoint, but also identified ST-segment depression in the high lateral leads (I and aVL) as a predictor of SCD. When the relative contribution of each predictor to the composite endpoint was examined with multivariable analysis, only ST-segment depression in the high lateral leads and syncope emerged as independent predictors. In spite of its still powerful reputation as a disease typified by premature death, most contemporary survival studies indicate that HCM is associated with a low annual risk of SCD. Nevertheless, it is clear that the susceptibility to ventricular arrhythmia varies substantially between individuals and so risk stratification remains central to clinical management. Patients with HCM develop ventricular arrhythmia for many reasons. Myocardial hypertrophy causes dispersion of repolarization and refractoriness making the myocardium vulnerable to triggered arrhythmias while the accompanying disarray and fibrosis create areas of conduction block … *Corresponding author. Tel: +44 2075728888, Fax: +44 2075738838, Email: perry.elliott{at}ucl.ac.uk

Prevalência e preditores da resposta cardioinibitória à massagem do seio carotídeo em 502 pacientes ambulatoriais

Cardioinhibitory response (CIR) is defined as asystole >3 seconds in response to 5-10 seconds of carotid sinus massage (CSM). Pacemaker implantation is indicated for patients with unexplained syncope episodes and CIR. To determine the prevalence and predictors of CIR in patients with a high prevalence of cardiovascular disease, and assess the clinical significance of CIR in patients with a history of unexplained syncope or falls. Cross-section design study. Outpatients, aged > or =50 years, referred to the electrocardiography sector of a tertiary hospital. Those with dementia, carotid bruit, and history of myocardial infarction, stroke or transient ischemic attack in the preceding 3 months were excluded. CSM was performed by a single investigator, with the patients in the supine position. CSM was applied on the right side and then on the left side during 10 seconds each time. 502 patients underwent CSM. CIR was present in 52 patients (10.4%; 95% CI: 7.7%-13%). Independent predictors of CIR were male gender (OR: 2.61%; CI 95%: 1.3%-5.1%), structural heart disease (OR: 3.28%; CI 95%: 1.3%-7.9%) and baseline heart rate (P<0.05). The sensitivity of the CIR to CSM in syncope evaluation was low (9.8%). Specificity was high (89.5%), being even better in women (95.3%) and in those without structural heart disease (96.2%). CIR was detected in 10.4% of the patients aged > or = 50 years. In males and in patients with structural heart disease CIR was more common. In women and patients with no apparent structural heart disease, the presence of CIR was a highly specific finding in the evaluation of syncope or falls.

Glue (Toluene) Abuse: Increased QT Dispersion and Relation with Unexplained Syncope

Exposure to toluene, one of the major components of glue, can lead to cardiac arrhythmias and sudden sniffing death syndrome. QT dispersion is a useful risk marker for cardiac arrhythmias and sudden cardiac death. The aim of this study was to investigate the effects of glue abuse on QT interval and QT dispersion. The study included 44 patients with inhalant abuse and 34 healthy controls. Patients were divided into three groups: glue abusers with history of unexplained syncope (n = 20), asymptomatic glue abusers (n = 24), and healthy control subjects (n = 34). QT intervals, QT dispersion, and corrected QT dispersion values were measured. QT and corrected QT duration were greater in the symptomatic group than in athe symptomatic group and greater in the asymptomatic group than in controls. QT and corrected QT dispersion in both symptomatic and asymptomatic group were significantly greater than controls (p= .001), and also QT and corrected QT dispersion in symptomatic group was greater in asymptomatic group (p = .001). These findings demonstrate that QT interval and corrected QT dispersion increase in symptomatic or asymptomatic toluene abusers. The QT and QTc dispersion were also found to be longer in the symptomatic group than those in the asymtomatic group.

Abstract 1657: Prophylactic Implantation Of Cardioverter Defibrillators In Patients With Severe Cardiac Amyloidosis

Objectives: Benefit of prophylactic implantation of a cardioverter defibrillator (ICD) in patients with cardiac light-chain amyloidosis (CA) was assessed. Background: CA carries a high risk for sudden cardiac death (SCD). Methods: Implantation of ICD was performed in 19 patients with histologically proven CA because of a high risk for SCD. These 19 patients were compared to historical controls of CA without ICD. Survival was defined as absence of death or heart transplantation. Definition of high risk for SCD was based on heart failure (NYHA ≥II), a history of unexplained syncope, interventricular septal thickness ≥15mm (IVS), left ventricular ejection fraction ≤45% (LVEF), ventricular premature contractions Lown ≥IVa, serum level of troponin T ≥0.03 μg/l (TnT) and/or a N-terminal-proBNP level ≥3500 ng/l. Results: Patients had NYHA class ≥II (n=17; 89%), syncopes (n=9; 47%), IVS ≥15mm (n=17; 89%), LVEF ≤45% (n=5; 26%), Lown ≥IVa (n=15; 79%), TnT &gt;0.03 μg/l (n=9; 47%), and NT-proBNP ≥3500 ng/l (n=12; 63%). There were no severe perioperative complications. During a median follow-up of 380 days 2 patients with sustained ventricular tachyarrhythmias were successfully treated by the ICD. There were 9 deaths from electromechanical dissociation (n=5), heart transplantation (n=2) or non-cardiac causes (n=2). Survival of ICD patients did not differ from matched controls. Non-survivors had higher NT-proBNP plasma levels (7576±1571 ng/l) than survivors (4036±737 ng/l, p&lt;0.05). Conclusions: ICD implantation in high-risk patients with CA is feasible, but while selected patients may benefit from an ICD, routine prophylactic implantation is not recommended. More specific predictors of SCD need to be identified.

Value of Symptoms to Predict Tilt Testing Outcome in Patients with Clinical Suspicion of Vasovagal Syncope

Studies to assess the value of clinical symptoms to predict the head-up tilt test (HUT) outcome in patients with suspicion of vasovagal syncope have shown controversial results. We undertook this study to compare the frequency of symptoms between subjects with and without history of syncope, its association with syncopal spells in those with a history of syncope and positive or negative HUT, and to identify clinical predictors of HUT outcome. Sixty seven subjects with a history of unexplained syncope and 26 subjects without a history of syncope were interviewed using a structured questionnaire before undergoing HUT, which was performed first in a passive phase and, if negative, was repeated with pharmacological challenge using 5 mg of sublingual isosorbide. Questionnaire included the 16 symptoms most frequently reported in previous studies. Only five symptoms were reported more frequently by subjects with history of syncope in comparison with subjects without it: visual blurring, dysesthesia, sighing dyspnea, tremor in fingers, and diaphoresis. Comparison of symptom frequency between patients with history of syncope and positive or negative HUT revealed that only two were significantly different: nausea and hot flashes. However, a detailed analysis of the data indicates that only hot flashes occurring just before the syncope were more common in those with a positive HUT. Although some symptoms were found more frequently in patients with a history of syncope than in those without it, the use of a structured questionnaire in the group of patients failed to predict the outcome of the HUT.

Investigation of Various Types of Neurocardiogenic Response to Head‐Up Tilting by Extended Hemodynamic and Neurohumoral Monitoring

The pathophysiology of neurocardiogenic syncope is heterogeneous. This study aim was to analyze whether extended monitoring during tilt-table testing provided additional information on the hemodynamic and vegetative state prior to neurocardiogenic syncope. This retrospective analysis is based on data of head-up tilt-table testing of 40 unselected consecutive patients with a history of unexplained syncope. For optimized characterization of the type of syncope, monitoring included electrocardiogram (ECG), blood pressure measurements and cardiac output, peripheral vascular resistance and contractility index measurements by impedance cardiography, as well as epinephrine and norepinephrine plasma levels in supine position and every 5 min during tilting. Seven of 40 patients were unsuitable for analysis because of incomplete data sets. Tilt-table was positive in 26 patients, negative in 7. Groups did not differ in hemodynamic and catecholaminergic parameters at baseline. Responses to tilting were VASIS 1 (mix of cardioinhibitory and vasodepressor) in 5 patients, VASIS 2B (cardioinhibitory with asystole >3 sec) in 3, VASIS 3 (vasodepressor) in 16, orthostatic dysregulation in 2. In VASIS 1, the catecholamine measurement 4 min before syncope showed a proportionally larger increase of the epinephrine level than of norepinephrine. This disproportion was not observed in VASIS 2B and 3. In VASIS 2B, strong vasoconstriction and negative inotropy were evident in the presyncopal period. In VASIS 3, vascular resistance decreased continuously before syncope, while contractility index increased inadequately. Presyncopal epinephrine surge or norepinephrine loss was not observed in this group, suspecting other vasodilating factors. Extended monitoring by impedance cardiography and plasma catecholamine measurements during tilt-table testing gave further insight into different hemodynamic and neurohumoral presyncopal patterns among the various types of neurocardiogenic syncope and may thereby help to develop individualized therapeutic concepts.

Long‐term prognosis in patients with bifascicular block – the predictive value of noninvasive and invasive assessment

Patients with bifascicular block (BFB) have a high mortality rate. The purpose of the present study was to identify high-risk patients in a BFB population by performing an extensive cardiac evaluation including noninvasive and invasive tests. Population-based study. A total of 100 patients with BFB, of whom 41 had a history of unexplained syncope, were prospectively studied. The mean age was 68 +/- 12. All patients were investigated with Holter-monitoring, an exercise test, an echocardiography, and an invasive electrophysiological study. The severity of congestive heart failure (CHF) was assessed by New York Heart Association (NYHA) classification. Patients in NYHA class IV were excluded. Patients with syncope were recommended prophylactic pacemaker treatment, which was accepted by 31 patients (76%). Main outcome measures. All-cause mortality and sudden cardiac death (SCD). During a median follow-up of 84 months, 33 patients died, of whom 14 in SCD. In a univariate analysis, high age, a previous myocardial infarction, and CHF were associated with a significantly increased risk of all-cause mortality and SCD. In a Cox multiple regression analysis, CHF was the only independent predictor of all-cause mortality and SCD (P < 0.01). Patients with BFB have a poor long-term prognosis. The predictive value of noninvasive and invasive investigations is limited. The only independent predictor of all-cause mortality and SCD in this population was the presence of CHF.