OBJECTIVES: The purpose of the current study was to determine the optimal duration of external loop recorder (ELR) monitoring in patients with presyncope or syncope and to identify factors that predict failure to activate the device effectively. DESIGN: A multivariate analysis was performed using data from the Comparison Of Loop ...

AIMS: The Reveal Plus implantable loop recorder offers additional automatic detection of arrhythmias that may not be symptomatic. We evaluated the clinical utility of this function compared with standard patient activation. METHODS: Over an 18 month period, 50 consecutive patients (age 54 +/- 20 years; 24 male) with unexplained dizziness, ...

Parameterization of the ST-segment is used as a tool for risk stratification for patients to suffer from ventricular tachycardia. This parameterization is performed in terms of Principal Component Analysis (PCA) applied on multichannel magnetocardiographic (MCG) recordings. 55-channel MCG was recorded from 14 normal persons, 10 patients with CHD, 14 patients ...

AIMS: After implantation of a cardioverter/defibrillator (ICD) predischarge testing is often performed to ensure appropriate therapy function. Nevertheless there is no proven evidence for the necessity of this examination. In this retrospective single-centre analysis we investigated the clinical value of routine predischarge testing. METHODS AND RESULTS: Predischarge testing was performed ...

The study evaluated all patients undergoing permanent pacemaker and ICD implantation over a 4-year period to determine if anticoagulated patients required normalization of coagulation factors in the periprocedural period. The study included 1,025 (597 men, 428 women, age 24-100 years, mean 72 years) consecutive patients who underwent device implantation using ...

Extrasystoles (RVES) from the right ventricular outflow tract (RVOT) are a common arrhythmia in routine ECGs. METHODS: In this prospective study 56 consecutive patients with RVES (22 males, 34 females) were examined for morphological and/or functional right ventricular (RV) abnormalities by 12-lead, Holter, exercise ECGs, transthoracic echocardiography and signal averaging. ...

Single chamber (SC) implantable cardioverter defibrillators (ICDs) have several limitations that might be relevant during follow-up, like atrial pacing requirements, inadequate therapies, sustained atrial tachyarrhythmias and difficulties to achieve an accurate diagnosis of the arrhythmia. Dual chamber (DC) ICDs offer an attractive and rational solution, although controversy remains if the ...

Postextrasystolic U wave augmentation is observed in patients with long QT syndrome and those with organic heart disease. This phenomenon is considered a marker of increased risk of arrhythmia. However, the characteristics of the U wave have not been evaluated in patients with idiopathic VT originating from the right ventricular ...

To study the clinical profile and genetic basis of Brugada syndrome in Chinese patients. Prospective observational study. Seven regional public hospitals, Hong Kong. The clinical and follow-up data of 50 patients (47 men, 3 women; mean age, 53 years) were collected, and genetic data of 36 probands and eight family ...

This study compared alterations in arterial catecholamine concentrations associated with tilt-induced vasovagal syncope that differed in older (>65 years) and younger patients (<35 years). Older patients with tilt-positive tests tended to exhibit higher baseline epinephrine (E) concentrations and lesser E surge before development of syncope than younger patients (<35 years), ...

OBJECTIVES: This study evaluated the effects of azimilide dihydrochloride (AZ) on anti-tachycardia pacing (ATP) and shock-terminated events in patients with implantable cardioverter defibrillators (ICDs). BACKGROUND: Animal studies have shown the effectiveness of AZ for therapy of supraventricular and ventricular tachycardia (VT). Azimilide dihydrochloride was investigated as adjunctive treatment for reducing ...

AIMS: Ventricular tachycardia (VT) frequently has an anatomical substrate. Identification of areas prone to arrhythmogenicity facilitates radiofrequency catheter ablation (RFCA). Furthermore, direct monitoring of complications potentially increases safety of RFCA. The aim of this study was to evaluate the feasibility of guiding RFCA of VT with intracardiac echocardiography (ICE), in ...

AIM: Recurrent syncope often remains unexplained despite extensive multidisciplinary screening. The implantable loop recorder (ILR) may be a tool to define the cardiac arrhythmias underlying syncope. METHODS AND RESULTS: The study population consisted of 43 consecutive patients with unexplained syncope who underwent extensive cardiological screening and were followed with an ...

The automatic ICD improves survival in patients with a history of sudden cardiac arrest. However, some patients do not meet the guidelines for ICD implantation or are unable to receive an implantable device. This study tested the hypothesis that these patients could benefit from a wearable cardioverter defibrillator. Patients with ...

To investigate the factors that may predict the effectiveness of beta-blocker therapy for congenital long QT syndrome (LQTS) in a Chinese patient population. Twenty-six LQTS patients were treated with oral propranolol (n=16) or metoprolol tartrate (n=10) for 38 months. Clinical symptoms, heart rate, corrected QT interval (QTc) and left ventricular ...

To assess the classification of neurocardiogenic syncope (NCS) as a IIA indication for pacemaker implantation in the recent American College of Cardiology/American Heart Association Task Force on Practice Guidelines/North American Society for Pacing and Electrophysiology guidelines, we performed chart reviews and follow-up interviews in a cohort of 45 consecutive young ...

It has been demonstrated that idiopathic ventricular fibrillation (VF) can be triggered by ventricular premature beats (VPBs) arising from the Purkinje fibers. Eliminating these VPBs by radiofrequency catheter ablation prevented VF recurrences. Whether the same pathophysiology and the same treatment option exist in patients with structural heart disease is unknown. ...

Neuromuscular electrical stimulation (NMES) is an option for increasing thigh muscle strength and endurance capacity in patients with chronic heart failure. Electromagnetic interference (EMI) by the signals with sensing of implantable cardioverter defibrillators (ICDs) is possible. The aim of the present pilot safety study was to test the safety of ...

INTRODUCTION: Ventricular tachycardia (VT) with involvement of the His-Purkinje system (HPS) can be difficult to recognize in patients with heart disease, but it may be particularly susceptible to ablation targeting the HPS. This study defines the incidence and types of HPS involvement in VT. METHODS AND RESULTS: Involvement of the ...

The MADIT-II study (Moss et al., N Engl J Med 2002;346:877-883) demonstrated that implantation of a cardioverter/defibrillator (ICD) reduced mortality from 19.8% to 14.2% during 20 months of follow-up in patients with prior myocardial infarction and left ventricular ejection fraction <or=0.30. Concerns have been raised both about the cost and ...

Biventricular pacing has emerged as a modality for treatment of patients with heart failure. Combined biventricular pacers and implantable cardioverter defibrillators offer treatment of heart failure as well as protection from sudden cardiac death. However, inappropriate ICD shocks as a result of double sensing due to widely spaced ventricular bipoles ...

In the absence of any published information on the indications, frequency, and outcomes of revision augmentation/mastopexy, an 8-year retrospective review was undertaken of all patients undergoing revision of a previous augmentation/mastopexy in the senior author's practice. The data collected included original implant type, location and mastopexy type, indication for revision, ...

We hypothesized that sympathetic nerve activity (SNA) remains elevated after tachycardia termination in patients with low baroreflex gain (BRG), and decreased to or below baseline in patients with high BRG. In a cohort of patients who participated in a previously published study [3], BRG, SNA, blood pressure, and central venous ...

The optimal duration of monitoring of patients with recurrent unexplained syncope who undergo prolonged monitoring with an implantable loop recorder is unknown. We examined the probability of syncope in a group of 167 patients with this condition who underwent prolonged monitoring with an implantable loop recorder. A 12-month monitoring period ...

OBJECTIVES: We administered pilsicainide chloride, a class Ic pure sodium channel blocker, to patients with Brugada syndrome (BS) and evaluated the occurrence of ventricular arrhythmia (VA) and T-wave alternans (TWA). BACKGROUND: Ventricular arrhythmia and TWA are sometimes induced by a sodium channel blocker challenge test in BS patients, but the ...

The electroanatomic mapping system Carto((R)) with its combination of anatomic and electrophysiologic information has substantially improved our understanding of arrhythmia mechanisms and substrates in patients with ventricular tachycardia (VT) and structural heart disease. Identification of the individual arrhythmogenic substrate and successful ablation guided by the combination of sinus rhythm voltage ...

BACKGROUND: Most patients admitted to the hospital from the emergency department (ED) with syncope do not have a myocardial infarction (MI), yet a common practice is to draw serial cardiac enzymes. METHODS: To assess the value of serial cardiac enzymes in elderly patients who present to the ED with syncope, ...

We report two cases who exhibited a decrease in their bispectral index (BIS) score, associated with syncope during venipuncture in patients with suspected needle phobia. In case 1, the reduction in BIS score occurred during the development of hypotension and bradycardia and may well have been caused by cerebral hypoperfusion. ...

BACKGROUND: In patients with left ventricular tachycardia (VT) and failed endocardial ablation, a subepicardial substrate may be considered. PATIENTS AND METHODS: Seven patients with drug-refractory VT of right bundle branch block morphology were investigated to identify the arrhythmogenic substrate using three-dimensional (3-D) electroanatomic endocardial and epicardial mapping. RESULTS: In three ...

The objective of this study was to investigate the clinical features of Korean patients with Brugada syndrome (BS). Between June 1998 and April 2002, 15 consecutive patients with BS (13 men, 2 women; mean age, 44+/-10 years) were identified. Eight patients had experienced at least 1 episode of aborted sudden ...

AIM: Although it has become standard practice to perform electrophysiologic studies in patients with unexplained syncope, limited information exists on prognosis after therapy guided by electrophysiologic studies. METHODS AND RESULTS: Electrophysiologic studies were performed in 643 patients with unexplained syncope. Electrophysiologic studies revealed conduction abnormalities and tachyarrhythmias accounting for syncope ...

Among 123 patients with unexplained syncope in the absence of heart disease who were followed up for 24 +/- 7 months, syncope recurred in a similar minority of them regardless of baseline tilt table testing results. An initially unsuspected cardiac or neuropsychiatric disorder was uncovered in 17 patients later on ...

The implantable loop recorder (ILR) has become an important tool for evaluating patients with recurrent syncope. Second generation ILRs have the ability to record events either automatically (auto activated) or by manual activation (patient activated). In an attempt to evaluate the relative utility of the auto-activation feature, this study stratified ...

Treatment of arrhythmogenic right ventricular dysplasia (ARVD) is mostly based on the prevention of sudden cardiac death that results from arrhythmias. A clinical history suggestive of ARVD requires careful evaluation including electrophysiological study. The potential ability to identify those patients who will have inducible VT with electrophysiological study will enable ...

The exact reentrant circuit of the verapamil-sensitive idiopathic left VT with a RBBB configuration remains unclear. Furthermore, if the fascicle of left bundle branch is involved in the reentrant circuit has not been well studied. Forty-nine patients with verapamil-sensitive idiopathic left VT underwent electrophysiological study and RF catheter ablation. Group ...

AIMS: Syncope in long QT syndrome (LQTS) is expected to be due to Torsades de Pointes ventricular tachycardia (TdP). Often these patients faint in situations with emotional stress. The aim of the present study was to evaluate whether neurocardiogenic syncope occurs in LQTS. METHODS AND RESULTS: Ten untreated consecutive LQTS ...

The purpose of this study was to assess the left ventricular sympathetic nervous system function in the patients with neurocardiogenic syncope (NCS) using I-123 metaiodobenzylguanidine (MIBG) imaging of the heart, and to compare the plasma noradrenaline (NA) and MIBG results of tilt positive and tilt negative patients following a head-up ...

We describe three cases of patients with Alzheimer's disease who presented with cardiac syncope soon after initiation of a cholinesterase inhibitor therapy (donepezil). Bradyarrhythmia was documented in two patients, considered probable in one, and was presumed related to the cholinergic therapy. Pacemaker implantation seemed justified rather than donepezil cessation. More ...

OBJECTIVES: The aim of this study was to examine the characteristics of non-sustained ventricular tachycardia (NSVT) episodes during Holter monitoring and to determine their relationship to age and prognosis. BACKGROUND: It has been suggested that NSVT is only of prognostic importance in patients with hypertrophic cardiomyopathy (HCM) when repetitive, prolonged, ...

BACKGROUND: The epicardial location of an arrhythmia could be responsible for unsuccessful endocardial catheter ablation. METHODS AND RESULTS: In 48 patients referred after prior unsuccessful endocardial ablation, we considered percutaneous, subxiphoid instrumentation of the pericardial space for mapping and ablation. Thirty patients had ventricular tachycardia (VT), 6 patients had a ...

External electrocardiographic loop recording permits extended cardiac rhythm monitoring and ECG storage before and after device activation. The purpose of the study was to assess the diagnostic yield of external loop recorders in patients with more than two syncopal events within the last 6 months and a negative tilt table ...

Despite considerable progress in the management of ischemic heart disease, a substantial proportion of patients continue to experience life-threatening arrhythmic events. The Multicenter Automatic Defibrillator Implantation Trial 2 has recently shown the superiority of implantable cardioverter defibrillators (ICDs) over conventional strategies to prevent sudden death in patients with reduced ejection ...

OBJECTIVE: To evaluate efficacy of the recently introduced implantable loop recorder (ILR) in establishing symptom-rhythm correlation in young patients with syncope, near syncope, palpitations, and acute life-threatening events (ALTEs). METHODS: A retrospective study was conducted with patients with ILR from 3 pediatric centers. Inclusion criteria were age <or=25 years and ...

Conventional activation or pacemapping is effective in guiding ablation of ventricular tachyarrhythmia originating from right ventricular outflow tract (RVOT). However, in selected patients with hemodynamically unstable or nonsustained tachycardia, noncontact mapping may be an effective alternative method to guide ablation in RVOT. Five patients with symptomatic hypotension during ventricular tachycardia ...

Patients with ICDs are commonly advised to quit industrial jobs because of concerns that strong electromagnetic fields operating in the industrial environment might interfere with ICD functions. This study was done to assess interactions between industrial equipment and ICDs, and to devise a simple low risk screening protocol. We studied ...

At present, patients with documented sustained VT or resuscitated cardiac arrest (CA) are treated with ICDs. The aim of this study was to retrospectively evaluate if a routine electrophysiological study should be recommended prior to ICD implantation. In 462 patients referred for ICD implantation because of supposedly documented VT (n ...

BACKGROUND: Although catheter mapping has been used to define the endocardial electrogram characteristics in patients with ventricular tachycardia (VT) and coronary disease, characterization of the electrophysiological substrate in patients with VT and nonischemic cardiomyopathy is limited. METHODS AND RESULTS: Left ventricular endocardial electroanatomical mapping was performed in 19 patients with ...

To evaluate the significance of inducible sustained ventricular tachycardia (VT) in patients with coronary artery disease and relatively preserved cardiac function, 33 patients who met the following criteria were studied; documented nonsustained VT but no history of life-threatening arrhythmia, inducible sustained VT at electrophysiologic study, and implantation of a cardioverter-defibrillator. ...

INTRODUCTION: Upper limit of vulnerability (ULV) has a strong correlation with defibrillation threshold (DFT) in patients with implantable cardioverter defibrillators (ICDs). Significant discrepancies between ULV and DFT are infrequent. The aim of this study was to characterize patients with such discrepancies. METHODS AND RESULTS: The ULV and DFT were determined ...

BACKGROUND: The prognostic role of asymptomatic nonsustained ventricular tachycardia (NSVT) and programmed ventricular stimulation (PVS) in patients with idiopathic dilated cardiomyopathy (IDC) remains controversial. METHODS: The prognostic significance of ventricular arrhythmias, ejection fraction, NYHA class, atrial fibrillation and age for overall and sudden death mortality was prospectively studied in 157 ...