Syncope is a transient loss of consciousness and postural tone, with spontaneous recovery, and may represent an episode of aborted cardiac arrest. The final common pathway for loss of consciousness from non-neurologic causes is hypoperfusion of the reticular activating system. The etiology of syncope in older patients frequently includes a ...

BACKGROUND: Recent studies have shown that patient-triggered cardiac event recorders (CER) have an increased diagnostic yield and are more cost effective than conventional 24-h-Holter electrocardiograms (ECGs) for the evaluation of sporadic, potentially arrhythmia-related symptoms. HYPOTHESIS: The aim of this study was to determine the diagnostic yield of a patient-triggered CER ...

The expanding indications for ICD therapy and the complexity of current devices will have impact on follow-up policy. The application of ICD therapy requires elaborate attention to technical aspects, arrhythmias, and the clinical course of the underlying disease. Currently, the quality of medical supervision is dependent on scheduled regular follow-up ...

OBJECTIVE: We sought to prospectively assess the diagnostic yielding of a protocol in which electrophysiologic studies (EPS), tilt-table tests (TTTs), and loop recorder implantation are selectively used. BACKGROUND: The optimal strategy in the diagnosis of patients with syncope of unknown cause has not been defined. METHODS: A total of 184 ...

Serious adverse events associated with electroconvulsive therapy (ECT) are uncommon and consist mostly of cardiovascular complications, mainly arrhythmias. The risk of complications is increased in elderly and physically ill patients. In the current study, a 24-hour pre-ECT and 24-hour post-ECT Holter recording was performed on 26 elderly patients during their ...

The frequencies of each type of arrythmia were investigated, by age and sex, among 3056 Brazilian patients with cardiac arrhythmia. Each patient investigated had been tested serologically for American trypanosomiasis and 1013 had been found seropositive for the disease. In general, the seropositive 'chagasic' patients were each likely to be ...

AF is frequent after cardiac surgery. However, ventricular arrhythmias are less known. The purpose of the study was to evaluate the causes and the prognostic significance of severe ventricular arrhythmias occurring after cardiac surgery. For 10 years, among 2,100 cardiac surgeries, 16 (0.8%) patients (13 men, 3 women; age 49-71 ...

Syncope is defined as a self-limited loss of consciousness, usually combined with falling due to the inability to maintain postural tone. The underlying mechanism is a transient global cerebral hypoperfusion. The aetiology essentially includes cardiac disorders (structured heart disease or arrhythmias), neurally-mediated reflex syndromes, orthostatic hypotension and carotid sinus syndrome. ...

Neurocardiogenic syncope is the most common cause of syncope in patients who present in outpatient clinics. Head-up tilt test (HUT) has been widely used to diagnose neurocardiogenic syncope. However, the HUT does not always produce a positive response in patients with suspected neurocardiogenic syncope. The aim of the present study ...

OBJECTIVES: We sought to assess outcomes in a series of young patients with Marfan syndrome and to define the prevalence of ventricular arrhythmias in this patient population. BACKGROUND: While sudden death is a well-recognized outcome in Marfan syndrome, ventricular arrhythmias are not well described. METHODS: Patients were followed with echocardiography, ...

Undesirable sensing of external sources of electromagnetic interference by ICDs is well known. A transcutaneous electrical nerve stimulation (TENS) device has been reported to interfere with an ICD resulting in an inappropriate shock and patients with implanted defibrillators or pacemakers have been cautioned about the use of such units to ...

BACKGROUND AND STUDY OBJECTIVE: Conventional programmed electrical stimulation (PES) is useful for establishing inducibility or noninducibility of clinical ventricular arrhythmias (VA), but is complex and time-consuming. This study compared a standard PES protocol with ultrarapid train stimulation (UTS) in a broad range of patients with and without a history of ...

In order to assess the diagnostic value of invasive electrophysiologic study (EPS) in the patients with unexplained syncope, the electrophysiologic findings of 268 patients with unexplained syncope despite a complete clinical evaluation were analyzed. Results showed positive EPS finding was 38% in total patients and 50% in the patients aged ...

Since 1992, the Brugada syndrome has been increasingly recognized worldwide, although its incidence and distribution remain unclear. In Asia, several cases have been reported in Japan, Thailand, Singapore, and Vietnam. However, little information is available from the Chinese population. Since June 1997, we have identified 10 patients with the diagnosis ...

The efficacy of amiodarone used in combination with a pacemaker cardioverter defibrillator (PCD) to decrease episodes of ventricular tachycardia and subsequent PCD shocks is not clear. We examined a retrospective registry of 82 patients with PCD implantation to define the efficacy of amiodarone treatment. We compared patients treated with amiodarone ...

The flecainide test is widely used in Brugada syndrome. However, its reproducibility and safety remain ill-defined. This study included 22 patients (18 men, mean age 34 years). Mutations in the SCN5A gene were found in eight patients. Two patients had aborted sudden cardiac death, 8 had syncope/presyncope, and 12 were ...

Modern dual chamber ICD systems are able to overcome various sensing problems. However, improvement of their performance is still required. The aim of this study was to assess the sensing function in 101 consecutive patients (84 men, 17 women; mean age 63 +/- 12 years; mean follow-up 24 +/- 4 ...

OBJECTIVE: To investigate the clinical outcome, ECG characteristics, and optimal treatment of catecholaminergic polymorphic ventricular tachycardia (CPVT), a malignant and rare ventricular tachycardia. PATIENTS AND METHODS: Questionnaire responses and ECGs of 29 patients with CPVT were evaluated. Mean (SD) age of onset was 10.3 (6.1) years. RESULTS: The initial CPVT ...

Implanted defibrillators have become mainstream therapy for the prevention of sudden cardiac death from ventricular tachyarrhythmias. A decade of studies has confirmed the superiority of ICDs over antiarrhythmic drug therapy in prolonging the life of patients with a prior history of sustained VT or VF. More recent studies have compared ...

BACKGROUND: Ventricular fibrillation (VF) and tachycardia (VT) are the common and potential life-threatening complications after CABG. Ischemic preconditioning (IP) has been proved effective in reducing ischemia reperfusion arrhythmia in animals and humans. Whether IP is effective in suppressing postoperative VF/VT in patients with CABG has not been studied. METHODS AND ...

The transvenous-catheter electrophysiologic (EP) study has occupied a central position in the investigation and management of patients with ischemic heart disease and a propensity to ventricular tachycardia (VT) or ventricular fibrillation (VF) for more than 25 years. However, demonstration of the superiority of the implantable cardioverter defibrillator (ICD) compared to ...

Dilated cardiomyopathy is a diverse group of heart diseases with variable arrhythmia substrates. The response to programmed stimulation is dependent on spontaneous arrhythmia presentation. In patients with dilated cardiomyopathy, the majority of sustained monomorphic VT is caused by a scar-related reentrant mechanism, similar to that of coronary artery disease. The ...

BACKGROUND: Fifty percent of deaths in patients with coronary disease occur suddenly. Although many factors correlate with increased mortality, there is little information regarding the influence of these factors on mode of death. As such, optimum methods to determine patients most likely to benefit from implantable defibrillator therapy are unclear. ...

OBJECTIVE: To determine whether bupropion overdose has been associated with cardiovascular toxicity. DATA SOURCES: MEDLINE (1966-January 2002), EMBASE (1980-January 2002), Current Contents (January 2002), and PubMed (January 2002) databases for English-language human reports. Search terms included bupropion, overdose (drug), intoxication, poisoning, and acute ingestion. DATA SYNTHESIS: Articles describing toxicity following ...

OBJECTIVE: To study the role of echocardiography in the stepwise evaluation of syncope. DESIGN: A prospective observational study with an 18 month follow up. SETTING: University teaching hospital providing primary and tertiary care. SUBJECTS: 650 consecutive patients with syncope and clinical suspicion of an obstructive valvar lesion, or with syncope ...

BACKGROUND: The finding of bundle branch block in patients with syncope suggests that paroxysmal AV block may be the cause of syncope, even though its prevalence is unknown. METHODS: We evaluated 55 consecutive patients with syncope and bundle branch block (mean age 75 +/- 8 years; median of two syncopal ...

Although the survival benefit conveyed by the automatic defibrillator has been well established for several subsets of patients, some patients who receive the device still die early. The relative lymphocyte count (%L), a portion of the white blood cell count differential, which is decreased in states of excess systemic stress, ...

OBJECTIVES: We sought to test the hypothesis that autoantibodies (Abs) produced against sarcolemmal Na-K-ATPase play a role in the development of ventricular tachycardia (VT) and cardiac sudden death in patients with dilated cardiomyopathy (DCM). BACKGROUND: Autoimmunity is one of the mechanisms of pathogenesis of DCM as well as virus infection ...

BACKGROUND: Methadone is an effective treatment for opioid dependency and chronic pain. A methadone derivative, levacetylmethadol, was withdrawn from the European market after being associated with torsade de pointes. To date, no association between methadone and this arrhythmia has been described. OBJECTIVE: To evaluate a series of methadone-treated patients experiencing ...

Age-related physiologic changes together with high prevalence of chronic illness and the use of multiple medications predispose older adults to syncope. The causes of many of these patients' syncope are unexplained and most remained symptomatic. A thoughtful diagnostic strategy is essential to pinpoint the cause in each patient. The initial ...

INTRODUCTION: Numerous reports on the inducibility of ventricular tachyarrhythmias (VT) in patients with atypical right bundle branch block and right precordial ST-elevation (Brugada syndrome) are based on multicentre studies that have used different stimulation protocols. Therefore, we prospectively investigated the inducibility of VT in these patients using a uniform protocol. ...

The interactions between systolic arterial pressure (SAP) and R-R interval (RR) fluctuations after acute myocardial infarction (AMI) were investigated by measures of synchronization separating the feedback from the feedforward control and capturing both linear and nonlinear contributions. The causal synchronization, evaluating the ability of RR to predict SAP (chi(s/t)) or ...

Patients with syncope of unknown origin are commonly evaluated using several diagnostic tools. It has been suggested that there is a significant overlap between the results of head-up tilt table testing (HUT) and carotid sinus massage (CSM). We retrospectively studied the association between tilt table test results and CSM outcome ...

If not diagnosed by history, examination, or ECG, the diagnosis of syncope can be difficult with a low yield from echocardiography, ambulatory ECG recording, electrophysiological study, and tilt table testing. During 2 years, 48 patients with unexplained syncope or presyncope from three hospitals in one city underwent the implantation of ...

OBJECTIVES: To investigate the value of head-up tilt table testing (HUTT) with low-dose isosorbide dinitrate (ISDN) in the evaluation of patients with unexplained syncope and to compare the results of HUTT with ISDN and HUTT with isoproterenol. PATIENTS AND METHODS: Forty-three patients with unexplained syncope (21 women, with a mean ...

INTRODUCTION: During head-up tilt (HUT) test, patients with neurocardiogenic syncope show a sudden severe decrease in heart rate at the beginning of their induced syncopal attacks (termed intermittency). They also exhibit slow and progressive increases in their mean heart rates long before the induced syncopal attacks (termed nonstationarity). The aim ...

INTRODUCTION: The value of noninvasive markers reflecting repolarization and/or conduction abnormalities in identifying patients with abnormal ECG showing a pattern of atypical right bundle branch block and ST elevation syndrome (Brugada syndrome) at risk for life-threatening arrhythmias is controversial. Because right precordial ST elevation reflects inhomogeneous repolarization, we hypothesized that ...

OBJECTIVES: To investigate the cause of worse survival in older patients after myocardial infarction (MI). DESIGN: Prospective 18-month and longer follow-up study of a cohort of 167 patients (mean age +/- standard deviation 58 +/- 12, including 71 aged >or=65) with acute MI for cardiac events, defined as cardiac death, ...

IMPLICATIONS: The number of patients supported by ventricular assist devices (VADs) that present for noncardiac surgery is increasing in our institution. Our recent experience with eight such patients is reported, along with a review of the most commonly implanted VADs and the anesthetic implications and considerations for VAD-supported patients undergoing ...

Right bundle branch block and ST segment elevation (RBBB-STE) in the right precordial leads have been reported as a distinct clinical and electrocardiographic syndrome in patients prone to ventricular fibrillation (VF) in the absence of structural heart disease (Brugada syndrome). The purpose of the study was to investigate the role ...

This study was designed to investigate whether, in patients with hypertrophic cardiomyopathy (HC), tilt-induced volume unloading triggers a peripheral reflex similar to that seen in patients with a history of vasovagal syncope or rather acts through an intrinsic cardiac mechanism secondary to diastolic dysfunction. Thirty-seven patients with HC (10 with ...

OBJECTIVES: We sought to compare the long-term survival rates of patients with sustained ventricular tachyarrhythmia after myocardial infarction (MI) who were treated according to the results of electrophysiological (EP) study either with amiodarone or an implantable cardioverter-defibrillator (ICD). BACKGROUND: Patients with sustained ventricular tachyarrhythmias after MI are at high risk ...

AIMS: To determine the effectiveness of the implantable cardioverter defibrillator (ICD) in preventing recurrence of syncope in patients with structural heart disease, previously unexplained syncope and inducible ventricular arrhythmias. METHODS: Thirty-eight patients with syncope, structural heart disease and inducible arrhythmias had an ICD implanted. All ICDs delivered antitachycardia pacing and ...

AIMS: Syncope is a frequent and potentially dangerous symptom. The epidemiological data are based on series mainly collected 20 years ago in the U.S.A. and do not adequately assist in the management of patients admitted now for this symptom in Europe. METHODS AND RESULTS: To evaluate prospectively the epidemiological aspects ...

INTRODUCTION: Radiofrequency ablation (RFCA) of ventricular tachycardia (VT) is a potential curative treatment modality. We evaluated the results of RFCA in patients with VT. METHODS AND RESULTS: One hundred fifty-one consecutive patients (122 men and 29 women; age 57 +/- 16 years) with drug-refractory VT were treated. Underlying heart disease ...

BACKGROUND: The endothelins are peptides with vasoconstricting and growth-promoting properties. Endothelin-1 (ET-1) is known for its direct positive inotropic and chronotropic effects on isolated heart, and for growth effects. The aim of this pilot study was to investigate the frequency distribution of a common polymorphism of the endothelin (ET-1) gene ...

Vasopressin is a vital homeostatic protein which regulates fluid balance via its antidiuretic effects and vascular tone via its vasoconstrictive effects. Endogenous vasopressin deficiency has been implicated in several disease states resulting in vasodilatory shock. In particular, vasopressin levels are low in patients following cardiac surgery and in those with ...

OBJECTIVES: The purpose of this study was to determine the mechanisms of sudden death (SD) in patients with ventricular tachyarrhythmias (ventricular tachycardia/ventricular fibrillation [VT/VF]) treated with an implantable cardioverter defibrillator (ICD). BACKGROUND: Despite ICD therapy, some patients with VT/VF still die suddenly. Optimal ICD use requires determination of the mechanisms ...

AIMS: To ascertain the proportion of adults with a pacemaker in situ attending the Accident and Emergency Department because of syncope or unexplained falls and the cause of index symptoms in these patients, including the prevalence of hypotensive syndromes. METHODS AND RESULTS: Patients presenting to the Accident and Emergency Department ...

INTRODUCTION: Two randomized trials (Multicenter Automatic Defibrillator Implantation Trial [MADIT] and Multicenter Unsustained Tachycardia Trial [MUSTT]) suggest that implantable cardioverter defibrillator (ICD) placement is associated with improved survival in patients with coronary artery disease, depressed left ventricular function, and nonsustained ventricular tachycardia (VT) who also have inducible sustained VT. However, ...