Physiologic Variants of Cardiac Conduction (Aberration, Gap, Supernormal Conduction).

Wide QRS complexes during supraventricular rhythms can be caused by fixed bundle branch block, functional (intermittent) bundle branch block, preexcitation, or toxic/metabolic causes. Functional bundle branch block can be caused by long-short aberrancy (usually physiologic), or acceleration/deceleration dependent aberrancy (usually pathologic). Electrocardiogram criteria have been proposed to differentiate aberration from ventricular tachycardia; they are not always accurate.

Thoracoscopic Left Atrial Appendage Exclusion for Atrial Fibrillation Patients Intolerant to Anticoagulation.

Objective: Outcomes associated with isolated epicardial left atrial appendage (LAA) exclusion in atrial fibrillation (AF) patients with a contraindication or intolerance to anticoagulation are not clearly defined, especially in patients with prior stroke. This study evaluated the perioperative safety, medication use, and stroke outcomes for isolated thoracoscopic LAA exclusion for stroke prevention.

Methods: A single-center retrospective study was performed of adults undergoing isolated thoracoscopic LAA exclusion with an epicardial exclusion device without a concomitant surgical procedure.

Left Atrial Appendage Clip Reentry: The Case for Ablation From the Appendage to Left Pulmonary Veins.

Convergent hybrid atrial fibrillation ablation combines epicardial posterior left atrial ablation with catheter pulmonary vein isolation. Concomitant left atrial appendage AtriClip placement has recently been included to mitigate stroke risk. We describe a 72-year-old woman with long-standing persistent atrial fibrillation in whom atrial flutter with reentry encircling the AtriClip developed 18 months after a successful convergent procedure.

Progression of ECG in hydroxychloroquine overdose.

Hydroxychloroquine overdose is associated with myocardial toxicity and conduction disorders. We report a case of hydroxychloroquine overdose that demonstrated a rapid progressive intraventricular conduction delay and QT prolongation resulting in significant bradycardia and shock despite aggressive treatment. We describe the rare capture of abrupt abnormalities of this overdose in sequential electrocardiograms in the immediate hours post-ingestion.

Why is the patient still symptomatic after myectomy for HCM!

We describe the case of a young female patient with hypertrophic cardiomyopathy (HCM) with a dual chamber implantable cardioverter defibrillator (ICD), and complete heart block from a prior septal ablation procedure. Due to persistent left ventricular outflow tract (LVOT) obstruction and symptoms, she underwent surgical myectomy. Her exertional symptoms continued despite improved LVOT flow parameters.

Physiologic Variants of Cardiac Conduction (Aberration, Gap, Supernormal Conduction).

Wide QRS complexes during supraventricular rhythms can be caused by fixed bundle branch block, functional (intermittent) bundle branch block, preexcitation, or toxic/metabolic causes. Functional bundle branch block can be caused by long-short aberrancy (usually physiologic), or acceleration/deceleration dependent aberrancy (usually pathologic). Electrocardiogram criteria have been proposed to differentiate aberration from ventricular tachycardia; they are not always accurate.

Cardiovascular Considerations for the Internist and Hospitalist in the COVID-19 Era.

It is clear that existing cardiovascular disease is a major risk factor for COVID-19 and related adverse outcomes. In addition to acute respiratory syndrome, a large cohort also develop myocardial or vascular dysfunction, in part from inflammation and renin angiotensin system activation with increased sympathetic outflow, cardiac arrhythmias, ischemia, heart failure, and thromboembolic complications that portend poor outcomes related to COVID-19. We summarize recent information for hospitalists and internists on the front line of this pandemic regarding its cardiovascular impacts and management and the need for cardiovascular consultation.

Minimally invasive thoracoscopic surgery is an effective approach for treating inappropriate sinus tachycardia.

Introduction: Inappropriate sinus tachycardia (IST) is characterized by increased heart rate out of proportion to normal physiologic demand. IST ablation is challenging for the electrophysiology community due to the epicardial location of the sinus node and the risk of phrenic nerve (PN) injury during catheter ablation. In this study, we investigated the safety and efficacy of a minimally invasive thoracoscopic surgery for elimination of IST.

Meta-Analysis Comparing Catheter-Guided Ablation Versus Conventional Medical Therapy for Patients With Atrial Fibrillation and Heart Failure With Reduced Ejection Fraction.

The prognostic benefit of catheter ablation (CA) for atrial fibrillation in the setting of heart failure (HF) with reduced ejection fraction (EF) is unclear. A systematic search of medical literature was limited to randomized controlled trials. The primary outcome was all-cause mortality, and secondary outcomes were HF hospitalizations, stroke, left ventricular EF improvement, change in 6-minute walk test, and change in Minnesota living with HF questionnaire (Δ MLHFQ).

Iatrogenic Ventricular Fibrillation after Direct-Current Cardioversion of Preexcited Atrial Fibrillation Caused by Inadvertent T-Wave Synchronization.

Direct-current cardioversion is an important means of managing arrhythmias. During treatment, carefully synchronizing energy delivery to the QRS complex is necessary to avoid ventricular fibrillation caused by a shock during the vulnerable period of ventricular repolarization, that is, a shock on the T wave. The presence of an accessory pathway and ventricular preexcitation can lead to difficulty in distinguishing the QRS complex from the T wave because of bizarre, wide, irregular QRS complexes and prominent repolarization.

Thoracoscopic Ablation With Appendage Ligation Versus Medical Therapy for Stroke Prevention: A Proof-of-Concept Randomized Trial.

Objective: Atrial fibrillation (AF) has a demonstrable effect on quality of life (QOL). Recurrent stroke occurs in 10% of patients with AF. The objective of this study was to demonstrate proof of concept that thoracoscopic pulmonary vein isolation and atrial appendage ligation (TPVIAL) could prevent recurrent stroke and could potentially improve QOL in patients with AF with a previous stroke.

Lead astray: minimally invasive removal of a pacing lead in the left ventricle.

Pacemaker and implantable cardioverter defibrillator (ICD) leads are placed routinely with few notable complications. A rarely described complication of transvenous lead placement is malpositioning into the left ventricle. This situation can cause additional complications in the form of thromboembolic events.

Appropriate evaluation and treatment of heart failure patients after implantable cardioverter-defibrillator discharge: time to go beyond the initial shock.

Multiple clinical trials support the use of implantable cardioverter-defibrillators (ICDs) for prevention of sudden cardiac death in patients with heart failure (HF). Unfortunately, several complicating issues have arisen from the universal use of ICDs in HF patients. An estimated 20% to 35% of HF patients who receive an ICD for primary prevention will experience an appropriate shock within 1 to 3 years of implant, and one-third of patients will experience an inappropriate shock.

Benefit of cardiac resynchronization in elderly patients: results from the Multicenter InSync Randomized Clinical Evaluation (MIRACLE) and Multicenter InSync ICD Randomized Clinical Evaluation (MIRACLE-ICD) trials.

Purpose: Heart failure (HF) affects five million patients each year with both prevalence and incidence increasing with age. At least 20% of hospital admissions in patients > age 65 are due to HF. Cardiac resynchronization therapy (CRT) has been shown to improve HF symptoms and decrease mortality.

Acute and long-term efficacy and safety of catheter cryoablation of the cavotricuspid isthmus for treatment of type 1 atrial flutter.

Background: Atrial flutter (AFL) is commonly treated by radiofrequency catheter ablation. Catheter-based cryoablation may be an effective alternative with potential advantages.

Objective: The purpose of this study was to study the acute and long-term safety and efficacy of catheter-based cryoablation for treatment of cavotricuspid isthmus-dependent (typical and reverse typical) AFL.

Patient evaluation of ICD recall communication strategies: a vignette study.

Introduction: Communication about the unprecedented number of implantable cardioverter defibrillator (ICD) recalls has proved challenging. While initial studies have explored the psychological impact of recalls on patients, the optimal way to communicate recalls is not currently known. This study investigated the way communication of a recall can affect patients' responses.