Assessment of facial video-based detection of atrial fibrillation across human complexion.

Background: Early self-detection of atrial fibrillation (AF) can help delay and/or prevent significant associated complications, including embolic stroke and heart failure. We developed a facial video technology, videoplethysmography (VPG), to detect AF based on the analysis of facial pulsatile signals.

Objective: The purpose of this study was to evaluate the accuracy of a video-based technology to detect AF on a smartphone and to test the performance of the technology in AF patients across the whole spectrum of skin complexion and under various recording conditions.

Detection of atrial fibrillation using an earlobe photoplethysmographic sensor.

Unlabelled: Atrial fibrillation (AF) is the most common cardiac arrhythmia in the world, associated with increased risk of thromboembolic events and an increased mortality rate. In addition, a significant portion of AF patients are asymptomatic. Current AF diagnostic methods, often including a body surface electrocardiogram or implantable loop recorder, are both expensive and invasive and offer limited access within the general community.

Detection of atrial fibrillation using contactless facial video monitoring.

Background: It is estimated that 33.5 million people in the world have developed atrial fibrillation (AF), and an estimated 30% of patients with AF are unaware of their diagnosis (silent AF).

Objective: The purpose of this study was to test a new technology for contactless detection of AF based on facial video recordings.

Atrial burst pacing with biphasic and monophasic waveforms for atrial fibrillation.

Background: Biphasic pacing is a novel mode of pacing that was suggested to increase cardiac conduction velocity as compared with cathodal monophasic pacing. We aimed to evaluate the safety and efficacy of rapid atrial pacing to convert atrial fibrillation (AF) to normal sinus rhythm.

Methods: Multiple biphasic (anodal/cathodal), reverse biphasic (cathodal/anodal), and monophasic (cathodal) atrial pacing therapies were performed among 12 patients undergoing left atrial catheter ablation for AF.

Catheter ablation of atrial fibrillation in the elderly.

Purpose Of Review: Atrial fibrillation is increasingly prevalent among older adults and is a major contributor to morbidity in this population due to associated strokes, heart failure, and quality of life impairment. Catheter ablation for atrial fibrillation is demonstrated to be superior to antiarrhythmic therapy for the control of symptomatic and medically refractory atrial fibrillation, but its safety and efficacy in the elderly are not well understood. Clinical trials to guide the optimal management strategy in this population are lacking.

Meta-analysis of the effect of radiofrequency catheter ablation on left atrial size, volumes and function in patients with atrial fibrillation.

The effects of radiofrequency catheter ablation (RFCA) on left atrial (LA) size, volumes, and function in patients with atrial fibrillation (AF) are not well understood. The aim of this study was to systematically review the effects of RFCA on LA size, volumes, and function in patients with AF. Medline, the Web of Science, the Cochrane Central Register of Controlled Trials, and the reference lists of retrieved reports were searched for relevant studies through April 2009.

Predictive capability of left atrial size measured by CT, TEE, and TTE for recurrence of atrial fibrillation following radiofrequency catheter ablation.

Background: Recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) has been well established and is in part related to left atrial (LA) size. The purpose of this study was to assess the predictive capability of LA diameter (LAD) and LA volume (LAV) by echocardiography and computed tomography (CT) to determine success in patients undergoing RFCA of AF.

Methods: Eighty-eight patients with paroxysmal or persistent AF who had undergone RFCA and had a prior transthoracic echocardiogram (TTE), transesophageal echocardiogram (TEE), and CT were enrolled in the study.

Comparison of antiarrhythmic drug therapy and radiofrequency catheter ablation in patients with paroxysmal atrial fibrillation: a randomized controlled trial.

Context: Antiarrhythmic drugs are commonly used for prevention of recurrent atrial fibrillation (AF) despite inconsistent efficacy and frequent adverse effects. Catheter ablation has been proposed as an alternative treatment for paroxysmal AF.

Objective: To determine the efficacy of catheter ablation compared with antiarrhythmic drug therapy (ADT) in treating symptomatic paroxysmal AF.

Time-dependent risk of Fidelis lead failure.

The Medtronic Sprint Fidelis leads (models 6930, 6931, 6948, 6949) are 6.6-F bipolar high-voltage implantable cardioverter-defibrillator electrodes that were first introduced in September 2004. In October 2007, Fidelis leads were removed from the market.

Right ventricular dysfunction and the incidence of implantable cardioverter-defibrillator therapies.

Introduction: Implantable cardioverter-defibrillator (ICD) therapy is well established in preventing sudden cardiac death in patients with left ventricular dysfunction. The influence of right ventricular (RV) function on ICD therapy for sudden cardiac death (SCD) is not known.

Methods: We retrospectively studied 222 patients receiving an ICD for primary prevention of SCD.

Effect of biventricular pacing during a ventricular sensed event.

Loss of biventricular (BiV) pacing occurs during ventricular sensed events such as frequent ventricular ectopy, nonsustained ventricular tachycardia, and intrinsic atrioventricular nodal conduction, such as in atrial fibrillation. Ventricular sense response (VSR) pacing, a novel cardiac resynchronization therapy pacing strategy, maintains BiV pacing during these sensed ventricular events. Patients who underwent echocardiographic optimization after BiV pacemaker implantation were enrolled, and aortic velocity-time integrals (VTIs) were recorded and compared during intrinsic conduction without pacing, optimized BiV pacing, and intrinsic conduction with VSR pacing alone.

Catheter ablation of atrial fibrillation in the elderly: where do we stand?

Catheter ablation has emerged as an important therapy for the management of drug refractory symptomatic paroxysmal and persistent atrial fibrillation (AF). Although the elderly account for the majority of patients with AF, limited data exists regarding the use of catheter ablation for elderly patients with AF. As AF ablation has become more widespread, ablation techniques have improved and the complication rate has decreased.

Comparison of outcomes in patients undergoing defibrillation threshold testing at the time of implantable cardioverter-defibrillator implantation versus no defibrillation threshold testing.

Background: Inability to perform defibrillation threshold (DFT) testing during implantable cardioverter defibrillator (ICD) implantation due to co-morbidities may influence long-term survival.

Methods: Retrospective review at The University of Michigan (1999-2004) identified 55 patients undergoing ICD implantation without DFT testing ("No-DFT group"). A randomly selected sample of patients (n = 57) undergoing standard DFT testing ("DFT group") was compared in terms of appropriate shocks, clinical shock efficacy and all-cause mortality.

Brugada syndrome with marked conduction disease: dual implications of a SCN5A mutation.

A 51-year-old woman presented with an episode of syncope. Upon further review she was found to have a typical Brugada type pattern on her electrocardiogram. She did not have evidence for structural heart disease.

Variation in left atrial transmural wall thickness at sites commonly targeted for ablation of atrial fibrillation.

Background: The number of catheter ablations performed for atrial fibrillation (AF) has increased dramatically over the past several years. Regional variation in left atrial (LA) wall thickness is known to exist but have not been described in detail. AF ablation success and complication rates may be related to regional differences in LA wall thickness.

Pulmonary vein isolation as an end point for left atrial circumferential ablation of atrial fibrillation.

Objectives: We sought to determine whether elimination of pulmonary vein (PV) arrhythmogenicity is necessary for the efficacy of left atrial circumferential ablation (LACA) for atrial fibrillation (AF).

Background: The PVs often provide triggers or drivers of AF. It has been shown that LACA is more effective than PV isolation in eliminating paroxysmal AF.

Venous thrombosis and stenosis after implantation of pacemakers and defibrillators.

Venous complications of pacemaker/ implantable cardioverter defibrillator (ICD) system implantation rarely cause immediate clinical problems. The challenge starts when patients come for system revision or upgrade. Numerous reports of venous complications such as stenosis, occlusions, and superior vena cava syndrome have been published.

Effects of left atrial ablation of atrial fibrillation on size of the left atrium and pulmonary veins.

Objectives: The purpose of this study was to determine the effect of left atrial circumferential ablation on the size of the left atrium and pulmonary veins (PVs).

Background: The long-term effects of left atrial circumferential ablation on left atrial and PV size and anatomy have not been analyzed in quantitative fashion.

Methods: PV and left atrial sizes were analyzed in 41 consecutive patients (mean age 54 +/- 12 years) with paroxysmal (n = 25) or chronic (n = 16) atrial fibrillation.

Mechanisms of recurrent atrial fibrillation after pulmonary vein isolation by segmental ostial ablation.

Objectives: The aim of this study was to determine the mechanisms responsible for recurrent atrial fibrillation (AF) after pulmonary vein isolation (PV) by segmental ostial ablation.

Background: Recovery of conduction into a previously isolated PV is a common observation when there is recurrent AF soon after segmental ostial ablation. However, the mechanisms of recurrent AF have been unclear.