Electrocardiogram Belt guidance for left ventricular lead placement and biventricular pacing optimization.

Background: Patients with ischemic cardiomyopathy, non-left bundle branch block, or QRS duration <150 ms have a lower response rate to cardiac resynchronization therapy (CRT) than did other indicated patients. The ECG Belt system (EBS) is a novel surface mapping system designed to measure electrical dyssynchrony via the standard deviation of the activation times of the left ventricle.

Objectives: The objectives of this study were to evaluate the efficacy of the EBS in patients less likely to respond to CRT and to determine whether EBS use in lead placement guidance and device programming was superior to standard CRT care.

Efficacy and Safety of an Extravascular Implantable Cardioverter-Defibrillator.

Background: The extravascular implantable cardioverter-defibrillator (ICD) has a single lead implanted substernally to enable pause-prevention pacing, antitachycardia pacing, and defibrillation energy similar to that of transvenous ICDs. The safety and efficacy of extravascular ICDs are not yet known.

Methods: We conducted a prospective, single-group, nonrandomized, premarket global clinical study involving patients with a class I or IIa indication for an ICD, all of whom received an extravascular ICD system.

Inapparent atrial flutter due to atrial dissociation.

Percutaneous and surgical procedures intended to potentially cure atrial fibrillation require creating lines of conduction block in specific locations throughout the atrial chambers. In patients presenting with recurrent atrial fibrillation, repeat procedures are often performed, resulting in more extensive regions of conduction block and the potential for regions of dissociated atrial rhythms. The present case describes a patient post-multiple ablation procedures who presented with a symptomatic atrial arrhythmia, the mechanism of which was hidden by the presence of extensive atrial dissociation.

Traversing and dilating venous collaterals: a useful adjunct in left ventricular electrode placement.

In patients receiving cardiac resynchronization therapy (CRT), the left ventricular electrode cannot always be positioned in the preferred lateral or posterolateral locations due to technical factors and anatomic variations in the coronary sinus. Recent reports also suggest that CRT outcomes are improved by pacing the site of latest dyssynchrony and accessing these regions is not always possible. We report the utility of applying a technique described in the interventional literature over the past 3 years, effectively traversing and dilating collateral channels.