Precordial electrocardiographic recording and QT measurement from a novel wearable ring device.

Background: The availability of portable and wearable electrocardiographic (ECG) devices has increased secondary to technological development. Single-lead ECG recordings have been shown to reliably detect and characterize cardiac rhythms such as atrial fibrillation. Acquisition of precordial electrodes for full 12-lead ECG reconstruction from bipolar recordings is complicated by the absence of a body ground/Wilson central terminal electrode.

Survey of current perspectives on consumer-available digital health devices for detecting atrial fibrillation.

Background: Many digital health technologies capable of atrial fibrillation (AF) detection are directly available to patients. However, adaptation into clinical practice by heart rhythm healthcare practitioners (HCPs) is unclear.

Objective: To examine HCP perspectives on use of commercial technologies for AF detection and management.

Predictors and implications of early left ventricular ejection fraction improvement in new-onset idiopathic nonischemic cardiomyopathy with narrow QRS complex: A NEOLITH substudy.

Background: Predictors and implications of early left ventricular ejection fraction (LVEF) improvement with guideline-directed medical therapy (GDMT) in new-onset idiopathic nonischemic cardiomyopathy (NICM) with narrow QRS complex are not well described. The objectives were to describe predictors of LVEF improvement after 3 months on GDMT and adverse cardiac events based on post-GDMT LVEF status (≤35% vs. >35%).

Characteristics and Outcomes of Concurrently Diagnosed New Rapid Atrial Fibrillation or Flutter and New Reduced Ejection Fraction.

Background: Characteristics and outcomes of concurrently diagnosed new rapid atrial fibrillation (AF) or atrial flutter (AFL) and new heart failure with reduced left ventricular ejection fraction (LVEF) are not well described.

Methods: A retrospective cohort study of subjects referred for expedited transesophageal echocardiography-guided rhythm-control strategies for concurrent new rapid AF/AFL and new LVEF ≤ 40% diagnosed during the same admission was analyzed.

Results: Twenty-five subjects (median age 57 years; 96% male; 96% Caucasian; median CHA DS -VASc = 2) presented with new AF (n = 18) or AFL (n = 7) with rapid ventricular rate (median 135 beats/min) and new reduced LVEF (median 27%; range, 10-37.

Incidence and Predictors of Complications During Cryoballoon Pulmonary Vein Isolation for Atrial Fibrillation.

Background: Cryoballoon pulmonary vein isolation (PVI) has emerged as an alternative to radiofrequency PVI for atrial fibrillation (AF). Data are lacking to define the rates and predictors of complications, particularly phrenic nerve injury (PNI).

Methods And Results: We evaluated a single-center prospective registry of 450 consecutive patients undergoing cryoballoon PVI between 2011 and 2015.

New-onset left bundle branch block-associated idiopathic nonischemic cardiomyopathy and left ventricular ejection fraction response to guideline-directed therapies: The NEOLITH study.

Background: Left ventricular ejection fraction (LVEF) response to guideline-directed medical therapy (GDMT) and to early cardiac resynchronization therapy (CRT) in new-onset idiopathic nonischemic cardiomyopathy (NICM) and left bundle branch block (LBBB) is not well described. CRT is recommended if LVEF remains ≤35% after at least 3 months of GDMT.

Objective: The purpose of this study was to describe LVEF response to GDMT at 3 months and to early CRT in new-onset LBBB-associated idiopathic NICM.

Electrical dysfunction associated with conductor externalization of a silicone left ventricular lead.

The St. Jude Medical QuickFlex LV lead family (St. Jude Medical, Inc.

Prophylactic lead extraction at implantable cardioverter-defibrillator generator change.

Background: Current implantable cardiac devices have a finite battery life of ≈3 to 7 years for implantable cardioverter-defibrillators. It is current practice to reuse all properly functioning intravascular leads. We tested the hypothesis that a strategy of prophylactic lead removal at the time of device change would be superior under some conditions to the current practice of lead reuse.

Frequency of toxicity with chemical conversion of atrial fibrillation with dofetilide.

Dofetilide is a class III antiarrhythmic agent approved for the maintenance of sinus rhythm in patients with persistent atrial fibrillation (AF). The goal of this study was to determine if chemical cardioversion (CCV) suggests a greater sensitivity to dofetilide and, therefore, portends a higher risk of proarrhythmia. We analyzed 99 consecutive patients with persistent AF who were loaded on dofetilide before cardioversion.

Insights into atrioventricular nodal function from patients displaying dual conduction properties: interactive and orthogonal pathways.

Background: There is a significant variability observed in the conduction properties of the atrioventricular node. In a subset of hearts, impulse transmission tends to fall into two distinct conduction regions, termed the slow and fast pathway, and a further subset are capable of dual conduction of a single input stimulus, termed double firing.

Methods And Results: In this article, we closely characterize two distinct responses in patients with double firing properties of the atrioventricular node, separating these into discrete types: those with slow and fast pathway interaction and interdependence (interactive), and those with independent pathway properties (orthogonal).

Extraction of defibrillator leads recalled for cable externalization and failure.

Background: The Riata implantable cardioverter-defibrillator lead was recalled by the Food and Drug Administration because of an increased rate of failure associated with cable externalization. Because of its mechanical separation, the Riata lead may be challenging to extract. We therefore examined the experience with Riata lead extractions at our institution.

Fluoroscopic screening of asymptomatic patients implanted with the recalled Riata lead family.

Background: The Food and Drug Administration recently issued a class I recall of the St. Jude Medical Riata implantable cardioverter-defibrillator lead presumably because of increased risk of electric failure and mechanical separation via inside-out abrasion. We sought to examine the incidence and time dependence of inside-out abrasion in asymptomatic patients implanted with the Riata lead.

Effect of coronary occlusion on intracardiac electrogram morphology.

Aims: The effect of coronary occlusion on the morphology of intracardiac electrograms (IKG) may be of diagnostic value in recipients of cardiac implantable electronic device (CIED) and in other patients at risk of ischaemic heart disease (IHD), but remains grossly uncharacterized. The aim of the current study was to examine the effect of total occlusions in the major coronary artery distributions on the IKG.

Methods And Results: Domestic crossbred pigs (n= 11, 20-30 kg) were implanted with dual-coil right ventricular defibrillators, and bipolar right atrial and left ventricular leads.