Mutation Type and a Genetic Risk Score Associate Variably With Brugada Syndrome Phenotype in Families.

Background: Brugada syndrome (BrS) is characterized by the type 1 Brugada ECG pattern. Pathogenic rare variants in (mutations) are identified in 20% of BrS families in whom incomplete penetrance and genotype-negative phenotype-positive individuals are observed. E1784K- is the most common mutation identified.

The Diagnostic Yield of Brugada Syndrome After Sudden Death With Normal Autopsy.

Background: Familial evaluation after a sudden death with negative autopsy (sudden arrhythmic death syndrome; SADS) may identify relatives at risk of fatal arrhythmias.

Objectives: This study aimed to assess the impact of systematic ajmaline provocation testing using high right precordial leads (RPLs) on the diagnostic yield of Brugada syndrome (BrS) in a large cohort of SADS families.

Methods: Three hundred three SADS families (911 relatives) underwent evaluation with resting electrocardiogram using conventional and high RPLs, echocardiography, exercise, and 24-h electrocardiogram monitor.

The ventricular ectopic QRS interval (VEQSI): Diagnosis of arrhythmogenic right ventricular cardiomyopathy in patients with incomplete disease expression.

Background: The ventricular ectopic QRS interval (VEQSI) has been shown to identify structural heart disease and predict mortality. In arrhythmogenic right ventricular cardiomyopathy (ARVC), early diagnosis is difficult using current methods, and life-threatening arrhythmias are common and difficult to predict.

Objective: The purpose of this study was to assess the utility of ventricular ectopic indices including VEQSI in ARVC diagnosis.

Novel electrocardiographic criteria for the diagnosis of arrhythmogenic right ventricular cardiomyopathy.

Aims: In order to improve the electrocardiographic (ECG) diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC), we evaluated novel quantitative parameters of the QRS complex and the value of bipolar chest leads (CF leads) computed from the standard 12 leads.

Methods And Results: We analysed digital 12-lead ECGs in 44 patients with ARVC, 276 healthy subjects including 44 age and sex-matched with the patients and 36 genotyped members of ARVC families. The length and area of the terminal S wave in V1 to V3 were measured automatically using a common for all 12 leads QRS end.

The Syndrome of Inter-atrial Conduction Block.

The formulation of the syndrome of interatrial conduction block is an important step for improved identification of patients at high risk of developing atrial fibrillation (those with advanced, that is, third degree interatrial block, which includes retrograde instead of normal activation of the left atrium). The rationale and potential benefits of prophylactic antiarrhythmic treatment of patients with advanced interatrial block currently seems not sufficiently convincing and requires further study including prospective trials. In addition to the identified future directions for research in this syndrome, it seems important also to explore novel electrocardiogram (ECG) methods (e.

QRS-ST-T triangulation with repolarization shortening as a precursor of sustained ventricular tachycardia during acute myocardial ischemia.

We present segments from a 24-hour 12-lead digital Holter recording in a 48-year-old man demonstrating transient ST elevations in the inferior leads that triggered sustained ventricular tachycardia/ventricular fibrillation (VT/VF) requiring cardioversion. The onset of VT was preceded by a gradual increase in the ST with marked QRS broadening that lacked distinction between the end of the QRS and the beginning of the ST (QRS-ST-T "triangulation"), and shortening of the QT interval not caused by an increased heart rate. This is a relatively rare documentation of the mechanisms immediately triggering sustained ventricular arrhythmias during acute myocardial ischemia obtained with 12-lead ECG.

Electrocardiographic methods for diagnosis and risk stratification in the Brugada syndrome.

The Brugada syndrome (BrS) is a malignant, genetically-determined, arrhythmic syndrome manifesting as syncope or sudden cardiac death (SCD) in individuals with structurally normal hearts. The diagnosis of the BrS is mainly based on the presence of a spontaneous or Na + channel blocker induced characteristic, electrocardiographic (ECG) pattern (type 1 or coved Brugada ECG pattern) typically seen in leads V1 and V2 recorded from the 4th to 2nd intercostal (i.c.

Computed bipolar precordial leads for improved P wave detection.

We present an excerpt from a 24-hour 12-lead Holter recording acquired in an 85-year-old man investigated for the Brugada syndrome. The rhythm cannot be determined because no P waves can be discerned due to the high level of noise and to merging of the T and P waves. The P waves, however, are clearly visible and the noise is considerably reduced in bipolar precordial leads computed from the standard unipolar precordial leads.

The Brugada Syndrome - Diagnosis, Clinical Implications and Risk Stratification.

The Brugada syndrome (BrS) is a hereditary arrhythmic syndrome manifesting as syncope or sudden cardiac death (SCD) in individuals without overt structural heart disease. Currently, its diagnosis is mainly based on the presence of a spontaneous or Na+-channel blocker induced so-called "type 1" Brugada electrocardiographic (ECG) pattern typically seen in leads V1 and V2 recorded from the 4th to 2nd intercostal spaces. Presently the main unresolved clinical problem in the BrS is the identification of patients at high risk of SCD who need implantable cardioverter-defibrillator (ICD).

Clinical utility of computed electrocardiographic leads.

The standard 12-lead electrocardiogram (ECG) is only one of the possible ways to present the voltage differences between the nine recording electrodes. Other "non-conventional" leads may be constructed by physically connecting two or more electrodes in a different manner or by computation from the digital 12-lead ECG. Examples include bipolar or multipolar precordial leads and bipolar chest leads (between one precordial and one limb electrode).

Thorough QT study of the effect of oral moxifloxacin on QTc interval in the fed and fasted state in healthy Japanese and Caucasian subjects.

Aims: The aims of this study were three-fold and were to (i) investigate the effect of food (fasted and fed state) on the degree of QT prolongation caused by moxifloxacin under the rigorous conditions of a TQT study, (ii) differentiate the effects on QTc that arise from changes in PK from those arising as a result of electrophysiological changes attributable to raised levels of C-peptide [11] offsetting in part the IKr blocking properties of moxifloxacin and (iii) characterize the QTc F profile of oral moxifloxacin (400 mg) in healthy Japanese volunteers compared with Caucasian subjects.

Methods: The study population consisted of 32 healthy non-smoking, Caucasian (n = 13) and Japanese (n = 19), male and female subjects, aged between 20-45 years with a body mass index of between 18 to 25 kg m(-2). Female volunteers were required to use an effective contraceptive method or be abstinent.

Characterization of early repolarization during ajmaline provocation and exercise tolerance testing.

Background: 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.

Objective: To examine the response to ajmaline provocation and exercise in potentially high-risk subjects with ER and without a definitive cardiac diagnosis.

Insulin at normal physiological levels does not prolong QT(c) interval in thorough QT studies performed in healthy volunteers.

Aims: Food is known to shorten the QT(c) (QT(c)I and QT(c)F) interval and has been proposed as a non-pharmacological method of confirming assay sensitivity in thorough QT (TQT) studies and early phase studies in medicines research. Intake of food leads to a rise in insulin levels together with the release of C-peptide in equimolar amounts. However, it has been reported that euglycaemic hyperinsulinemia can prolong the QT(c) interval, whilst C-peptide has been reported to shorten the QT(c) interval.

Specificity of elevated intercostal space ECG recording for the type 1 Brugada ECG pattern.

Background: Right precordial (V1-3) elevated electrode placement ECG (EEP-ECG) is often used in the diagnosis of Brugada syndrome (BrS). However, the specificity of this has only been studied in smaller studies in Asian populations. We aimed to study this in a larger European population.

Dialysis-dependent changes in ventricular repolarization.

Background: Epidemiological data suggest increased risk of sudden death during and immediately after hemodialysis. Microvolt T-wave alternans (mTWA) is an electrocardiogram (ECG) measure of abnormal ventricular repolarization, which can be used in sudden death risk stratification. The aim of this study was to determine whether mTWA measurements during dialysis indicate abnormal repolarization as a potential trigger to dialysis associated arrhythmias.

Ventricular automaticity as a predictor of sudden death in ischaemic heart disease.

Opinion has oscillated in the cardiology community regarding the significance of ventricular premature beats and non-sustained ventricular tachycardia as predictors of sudden cardiac death. Automaticity can be a marker of underlying structural heart disease. It is unclear whether the apparent association with sudden death is simply a reflection of this fact.

Prevalence of the type 1 Brugada electrocardiogram in Caucasian patients with suspected coronary spasm.

Aims: Sporadic cases have reported the coexistence of coronary spasm and Brugada syndrome. However, the prevalence of the Brugada phenotype in coronary spasm is unknown, particularly in non-Japanese populations. In this study, we sought to examine the prevalence of the type 1 Brugada electrocardiogram (ECG) in a large European patient population undergoing intracoronary provocation testing for suspected coronary spasm.

Utility of high and standard right precordial leads during ajmaline testing for the diagnosis of Brugada syndrome.

Aims: The authors sought to assess the value of the high right precordial leads (RPL) to detect the Type I Brugada ECG pattern in patients suspected of carrying Brugada syndrome (BrS).

Methods: Ajmaline testing using 15-lead ECGs was performed in 183 patients suspected of carrying BrS. Standard 12-lead ECG with V1-V3 recorded from the fourth intercostal space and an additional three leads placed over V1-V3 recorded from the third intercostal space were analysed.

Heart rate turbulence for prediction of heart transplantation and mortality in chronic heart failure.

Background: Previous studies have shown conflicting results about the value of heart rate turbulence (HRT) for risk stratification of patients (pts) with chronic heart failure (CHF). We prospectively evaluated the relation between HRT and progression toward end-stage heart failure or all-cause mortality in patients with CHF.

Methods: HRT was assessed from 24-hour Holter recordings in 110 pts with CHF (54 in NYHA class II, 56 in class III-IV; left ventricular ejection fraction (LVEF) 30%+/- 10%) on optimal pharmacotherapy and quantified as turbulence onset (TO,%), turbulence slope (TS, ms/RR interval), and turbulence timing (beginning of RR sequence for calculation of TS, TT).