Ambulatory ECG monitoring for syncope and collapse in United States, Europe, and Japan: The patients' viewpoint.

Background: Practice guidelines provide clinicians direction for the selection of ambulatory ECG (AECG) monitors in the evaluation of syncope/collapse. However, whether patients' understand differences among AECG systems is unknown.

Methods And Results: A survey was conducted of USA (n = 99), United Kingdom (UK)/Germany (D) (n = 75) and Japan (n = 40) syncope/collapse patients who underwent diagnostic AECG monitoring.

An unyielding valve leading to venous spasm during pacemaker implantation: a case report.

Background: Subclavian venous spasm is an uncommon complication during permanent pacemaker implantation. The exact aetiology of subclavian venous spasm is not clear but has been suggested to be due to either mechanical irritation of the vein during needle puncture or due to chemical irritation from contrast injection. Here, we report a case of an unyielding subclavian vein valve that impeded guidewire advancement and the repeated guidewire manipulation led to venous spasm.

Neurohormones in the Pathophysiology of Vasovagal Syncope in Adults.

Vasovagal syncope (VVS) is the most common cause of syncope across all age groups. Nonetheless, despite its clinical importance and considerable research effort over many years, the pathophysiology of VVS remains incompletely understood. In this regard, numerous studies have been undertaken in an attempt to improve insight into the evolution of VVS episodes and many of these studies have examined neurohormonal changes that occur during the progression of VVS events primarily using the head-up tilt table testing model.

Swallow (deglutition) syncope: An evaluation of swallowing-induced heart rate and hemodynamic changes in affected patients and control subjects.

Background: Syncope triggered by swallowing is a well-known but uncommon condition that has been the focus of case reports but is otherwise largely unstudied. To better understand swallow syncope we examined heart rate (HR) and blood pressure (BP) changes during swallowing in clinically suspected swallow syncope patients and asymptomatic control subjects.

Methods: The study population comprised four individuals with a history suggesting swallow syncope (three men, 53 ± 14.

ECG electrode reversals: An opportunity to learn from mistakes.

An ECG with an "odd" appearance may raise the suspicion that ECG recording electrodes may have been reversed. Odd appearances include unexpected Q-waves or R-waves, markedly isoelectric leads, and abrupt changes from previous ECGs. A few examples of ECG electrode reversal provide the opportunity to review some fundamental principles of ECG recording.

Ambulatory diagnostic ECG monitoring for syncope and collapse: An assessment of clinical practice in the United States.

Introduction: Diagnostic ambulatory electrocardiogram (AECG) monitoring is widely used for evaluating syncope and collapse, and practice guidelines provide recommendations regarding optimal AECG device selection. However, whether physicians utilize AECGs in accordance with the pertinent guidelines is unclear. This study assessed utilization of AECG monitoring systems for syncope and collapse diagnosis by physicians in the United States.

Blunted Chronotropic Response to Hypotension in Cough Syncope.

Objectives: This study compared hemodynamic and chronotropic responses to cough in cough syncope (CS) patients to those in control subjects.

Background: Cough syncope is an uncommon form of situational fainting variously attributed to both reflex and mechanical causes. We hypothesized that if baroreflex responses contribute to CS, post-cough hypotension should be associated with cardioinhibition comparable to that observed in other reflex faints.

Usefulness of Atrial Fibrillation as a Marker for Adverse Cardiovascular Outcomes in Both Primary and Secondary Prevention in Patients With Implantable Cardioverter-Defibrillators.

Whether the risk factors for cardiovascular (CV) outcomes are different in primary versus secondary prevention implantable cardioverter-defibrillator (ICD) patients is unclear. We sought to identify predictors of CV outcomes in ICD recipients for primary (G1) versus secondary prevention (G2). Consecutive patients who had ICD implanted during August 2005 to December 2009 were included.

Arrhythmias in Patients with Cardiac Implantable Electrical Devices after Implantation of a Left Ventricular Assist Device.

Utilization of continuous-flow left ventricular assist devices (CF-LVADs) for advanced heart failure is increasing, and the role of cardiac implantable electrical devices (CIED) is unclear. Prior studies of the incidence of arrhythmias and shocks are frequently limited by ascertainment. One hundred and seventy-eight patients were examined with a previous CIED who were implanted with a CF-LVAD.

Cardiac pauses in competitive athletes: a systematic review examining the basis of current practice recommendations.

Aims: It is generally recommended that individuals aspiring to competitive sports should undergo pre-participation cardiovascular assessment, particularly including arrhythmia risk evaluation. In regard to bradyarrhythmias, the 36th Bethesda Conference suggested that asymptomatic cardiac pauses ≤3 s are 'probably of no significance', whereas longer 'symptomatic' pauses may be abnormal. This study focused on assessing the evidence for the '3 s' threshold.

Time course of appropriate implantable cardioverter-defibrillator therapy and implications for guideline-based driving restrictions.

Background: American Heart Association/Heart Rhythm Society recommendations restrict driving in implantable cardioverter-defibrillator patients for 6 months after implant for secondary prevention or primary prevention with an appropriate therapy (antitachycardia pacing or shock) for ventricular arrhythmias (VA).

Objective: The purpose of this study was to analyze implantable cardioverter-defibrillator therapy data to inform guideline recommendations on driving.

Methods: The OMNI Registry was queried for VA and assessed for the time course of appropriate therapies.

R-wave sensing in an implantable cardiac monitor without ECG-based preimplant mapping: results from a multicenter clinical trial.

Introduction: Reducing the form factor of an implantable cardiac monitor (ICM) may simplify device implant. This study evaluated R-wave sensing at a range of electrode distances and a preferred device implant location without mapping.

Methods: Patients scheduled for a Medtronic Reveal® ICM implant (Medtronic Inc.

Syncope and driving, flying and vocational concerns.

When advising a syncope patient about resumption of driving, flying or vocational activities, physicians must consider relevant laws and regulations, the etiology of the syncope, and the risk of recurrence and the impact of recurrence on the safety of the patient and others. Guidelines from professional cardiology societies may aid the physician. In the United States, private driving is regulated by individual states and their laws show significant variance.

Age-dependence of relative change in circulating epinephrine and norepinephrine concentrations during tilt-induced vasovagal syncope.

Background: Although vasovagal syncope (VVS) is preceded by a surge of circulating catecholamines (epinephrine [Epi] and norepinephrine [NE]) of adrenal/renal and synaptic origin, prevention of VVS with β-adrenergic blockade has been ineffective except in "older" VVS patients.

Objective: We hypothesized that age-related differences of β-blocker effect may be due in part to differences in the relative magnitudes of Epi and NE release during an evolving faint, specifically, greater Epi/NE ratio in younger fainters compared to older patients. To assess this hypothesis, we measured changes in Epi/NE ratios in younger (<40 years) vs older (≥40 years) patients during head-up tilt-table test-induced VVS.

Response to the Center for Medicare & Medicaid Services coverage with evidence development request for primary prevention implantable cardioverter-defibrillators: data from the OMNI study.

Background: The Center for Medicare & Medicaid Services expanded coverage for primary prevention (PP) implantable cardioverter-defibrillators (ICDs) included a request for outcome comparisons between 3 Group B subgroup patients (left ventricular ejection fraction [LVEF] 31%-35%, nonischemic dilated cardiomyopathy [NDCM] duration of <9 months, and New York Heart Association class IV heart failure (HF) treated with cardiac resynchronization therapy/defibrillator [CRT/D]) and non-Group B patients (LVEF ≤30%, NDCM duration of ≥9 months, and New York Heart Association class III HF treated with CRT/D) using real-world observational studies.

Objective: To compare outcomes in Center for Medicare & Medicaid Services Group B and non-Group B PP ICD patients.

Methods: OMNI was a 4-year prospective observational study that enrolled 1464 PP ICD patients with a mean LVEF of 25%; 72% were men, 78% had class II-IV HF, and 66% had coronary disease.

Relationship of paroxysmal atrial tachyarrhythmias to volume overload: assessment by implanted transpulmonary impedance monitoring.

Background: Clinical experience suggests that atrial tachyarrhythmias (ATs) are a frequent comorbidity in heart failure patients with left ventricular systolic dysfunction and that volume overload may increase AT susceptibility. However, substantiating this apparent relationship in free-living patients is difficult. Recently, certain implantable cardioverter-defibrillators provide, by measuring transpulmonary electric bioimpedance, an index of intrathoracic fluid status (OptiVol index [OI]).

Arrhythmogenic right ventricular cardiomyopathy/dysplasia clinical presentation and diagnostic evaluation: results from the North American Multidisciplinary Study.

Background: Prior reports on patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) focused on individuals with advanced forms of the disease. Data on the diagnostic performance of various testing modalities in newly identified individuals suspected of having ARVC/D are limited.

Objective: The purpose of the Multidisciplinary Study of Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia was to study the clinical characteristics and diagnostic evaluation of a large group of patients newly identified with ARVC/D.

Reduced atrial tachyarrhythmia susceptibility after upgrade of conventional implanted pulse generator to cardiac resynchronization therapy in patients with heart failure.

Objectives: We sought to identify the impact of cardiac resynchronization therapy (CRT) on atrial tachyarrhythmia (AT) susceptibility in patients with left ventricular (LV) systolic dysfunction in whom worsening heart failure (HF) resulted in upgrade from conventional dual-chamber pulse generator to cardiac resynchronization therapy-defibrillator (CRT-D).

Background: Cardiac resynchronization therapy with a defibrillator improves survival rates and symptoms in patients with LV systolic dysfunction but little is known about its effects on AT incidence in the same patient population.

Methods: Twenty-eight consecutive HF patients who underwent device upgrade to CRT-D were included.

Increased impedance to inspiration ameliorates hemodynamic changes associated with movement to upright posture in orthostatic hypotension: a randomized blinded pilot study.

Background: Movement to upright posture may result in marked drop of blood pressure with susceptibility to injury from syncope and falls in patients with orthostatic hypotension.

Objective: The purpose of this study was to determine if increasing negative intrathoracic pressure by using an inspiratory impedance threshold device before change of posture diminishes blood pressure fall by enhancing venous return.

Methods: Eighteen healthy subjects and 22 orthostatic hypotension patients were randomized to either an active (impedance 7 cmH2O) or sham (no inspiratory impedance) impedance threshold device.

Syncope in adults: terminology, classification, and diagnostic strategy.

Syncope is a relatively common clinical syndrome that is a subset of a broader range of conditions that cause transient loss of consciousness (TLOC). Other TLOC conditions include seizures, concussions, and intoxications. However, despite frequent confusion in the medical literature, syncope is and should be clearly distinguished from those other causes of TLOC by virtue of its pathophysiology; specifically, syncope is the result of self-terminating inadequacy of global cerebral nutrient perfusion, while the other forms of TLOC have different etiologies.

Impact of upgrade to cardiac resynchronization therapy on ventricular arrhythmia frequency in patients with implantable cardioverter-defibrillators.

Objectives: This study compared cardiac resynchronization therapy's (CRT) impact on ventricular tachyarrhythmia susceptibility in patients who, due to worsening heart failure (HF) symptoms, underwent a replacement of a conventional implantable cardioverter-defibrillator (ICD) with a CRT-ICD.

Background: Cardiac resynchronization therapy is an effective addition to conventional treatment of HF in many patients with left ventricular systolic dysfunction. However, whether CRT-induced improvements in HF status also reduce susceptibility to life-threatening arrhythmias is less certain.