Wide Complex Tachycardia in a Right-Sided Heart: Diagnostic and Therapeutic Challenges.

Dextroposition is a rare cardiac malformation defined as heart shift to right of midline. ECG findings vary with degree of displacement within the chest cavity. We report the second known case of dextroposition with accessory pathway (posteroseptal in our patient), presenting as pre-excited atrial tachycardia.

Swallow Syncope Associated With Intermittent Sinus Pause and High-Degree Atrioventricular Block: A Case Report.

Swallow syncope, also known as deglutition syncope, is a relatively rare neurogenic disorder that is triggered by oral intake. When diagnosed, swallow syncope is treatable, but it is challenging to identify without proper history and prior knowledge of this disorder. Here, we describe the case of a 68-year-old female with a complex history who presented to the emergency room with complaints of worsening long-term intermittent lightheadedness and dizziness associated with swallowing.

Correlation of scar in cardiac MRI and high-resolution contact mapping of left ventricle in a chronic infarct model.

Background: Endocardial mapping for scars and abnormal electrograms forms the most essential component of ventricular tachycardia ablation. The utility of ultra-high resolution mapping of ventricular scar was assessed using a multielectrode contact mapping system in a chronic canine infarct model.

Methods: Chronic infarcts were created in five anesthetized dogs by ligating the left anterior descending coronary artery.

Iron deposition following chronic myocardial infarction as a substrate for cardiac electrical anomalies: initial findings in a canine model.

Purpose: Iron deposition has been shown to occur following myocardial infarction (MI). We investigated whether such focal iron deposition within chronic MI lead to electrical anomalies.

Methods: Two groups of dogs (ex-vivo (n = 12) and in-vivo (n = 10)) were studied at 16 weeks post MI.

Prevention of esophageal thermal injury during radiofrequency ablation for atrial fibrillation.

Pulmonary vein isolation using radiofrequency ablation is an effective therapy in patients with atrial fibrillation. However, the esophagus descends in close proximity to the posterior wall of the left atrium and renders this structure susceptible to thermal injury. Esophageal ulceration has been hypothesized to be a precursor to left atrial-esophageal fistula, a procedural complication associated with poor prognosis.

Approach to the difficult septal atrioventricular accessory pathway: the importance of regional anatomy.

Ablation of accessory tracts in the posteroseptal region can be challenging, as illustrated by these 2 cases. Familiarity of the anatomy of this region and recognition of the ECG patterns can help identify the AP origin and potentially improve success rates of ablation. The isoelectric initial preexcited QRS complex with rSR’ pattern in lead V1 of the surface ECG but not the relatively earlier local ventricular activation at PSMA region may indicate a left-sided ablation approach for these APs.

Electrophysiological characteristics of focal atrial tachycardia surrounding the aortic coronary cusps.

Background: Catheter ablation of atrial tachycardia (AT) arising near the coronary cusps has been reported in limited numbers of patients. We investigated the electrophysiological characteristics of these ATs in 22 consecutive patients.

Methods And Results: This study included 22 patients (mean age ± SD, 53 ± 11 years; 86% female) with ATs arising near the aortic coronary cusps who underwent successful ablation.

Spontaneously alternating forms of the atrioventricular node reentrant tachycardia.

We present a case of atrioventricular node reentrant tachycardia that displays spontaneously alternating antegrade and retrograde conduction via 1:2 manners.

Inducibility of atrial fibrillation in the absence of atrial fibrillation: what does it mean to be normal?

Background: While inducibility of atrial fibrillation (AF) is often used as an endpoint for radiofrequency ablation of AF, little is known regarding inducibility among normals. We therefore evaluated the inducibility of AF with rapid atrial pacing in patients without a clinical history of AF after catheter ablation of supraventricular tachycardia (SVT).

Methods: We prospectively evaluated 86 patients with no history of AF who were referred for catheter ablation of SVT.

Natural antibodies and complement modulate intimal thickening after arterial injury.

Immune factors are involved in modulating neointimal response to arterial wall injury, but the role of individual immune effectors in this response remains unclear. Using a carotid cuff injury model in mice, we tested the role of immunoglobulin isotypes in modulating intimal thickening by using adoptive transfer of splenocytes from WT mice, or the direct administration of IgG or IgM into immune-deficient Rag-1-/- [Rag-1 knockout (Rag-1KO)] mice. The direct role of complement was also tested by depletion of complement.

Comparison of drug-eluting stents with bare metal stents in unselected patients with acute myocardial infarction.

Objectives: The aim of this study was to compare the procedural characteristics and outcomes of patients with acute myocardial infarction treated with drug-eluting stents (DES) vs. bare metal stents (BMS).

Background: DES have been shown to reduce the incidence of restenosis and target vessel revascularization (TVR) in clinical randomized studies when compared with BMS in patients undergoing elective percutaneous intervention.