John D. Day

Patients treated with catheter ablation for atrial fibrillation have long-term rates of death, stroke, and dementia similar to patients without atrial fibrillation.

Outcomes in Patients With AF.u2002Introduction:u2002Atrial fibrillation (AF) adversely impacts mortality, stroke, heart failure, and dementia. AF ablation eliminates AF in most patients. We evaluated the long‐term impact of AF ablation on mortality, heart failure (HF), stroke, and dementia in a large system‐wide patient population.

Long-Term Clinical Efficacy and Risk of Catheter Ablation for Atrial Fibrillation in Octogenarians

Background: Radiofrequency ablation is an effective treatment for atrial fibrillation (AF). With improved safety, the therapy has been offered to increasingly older populations. Arrhythmia mechanisms, medical comorbidities, and safety may vary in the very elderly population.

Atrial Fibrillation Significantly Increases Total Mortality and Stroke Risk Beyond that Conveyed by the CHADS2 Risk Factors

Background: Atrial fibrillation (AF) is associated with an increased risk of mortality and stroke. However, it is unclear if AF is independently associated with these poor outcomes or it is merely a risk marker of other processes that convey the risk.

Atrial Fibrillation and CHADS2 Risk Factors are Associated with Highly Sensitive C‐Reactive Protein Incrementally and Independently

Background: Inflammation has been shown to have a direct role in the initiation, maintenance, and recurrence of atrial fibrillation (AF) although the underlying mechanisms are unknown. Similarly, it is unclear if inflammatory markers are elevated due to the AF alone or the coexisting cardiovascular diseases that increase the risk of AF.

Implantable Cardioverter Defibrillators: Do Women Fare Worse Than Men? Gender Comparison in the INTRINSIC RV Trial

Introduction: Due to limited enrollment of women in previous trials, there is a paucity of data comparing outcome and arrhythmic events in men versus women with implantable cardioverter defibrillators (ICDs).

Atrial fibrillation hospitalization is not increased with short-term elevations in exposure to fine particulate air pollution.

Background: Previous studies have observed that short‐term exposure to elevated concentrations of particulate matter (PM) air pollution increases risk of acute ischemic heart disease events and heart failure hospitalization, alters cardiac autonomic function, and increases risk of arrhythmias. This study explored the potential associations between short‐term elevations in PM exposure and atrial fibrillation (AF).

A strategy of rapid cardioversion minimizes the significance of early recurrent atrial tachyarrhythmias after ablation for atrial fibrillation.

A Strategy of Rapid Cardioversion.u2002Background: The significance of early recurrent atrial tachyarrhythmias after atrial fibrillation (AF) ablation is unclear. Atrial remodeling driven by these tachyarrhythmias can result in electrical, contractile, and structural changes that may impair long‐term therapy success. Aggressive attempts to restore sinus rhythm in the temporal period of healing after ablation might improve outcomes.

Intracardiac Ultrasound for Esophageal Anatomic Assessment and Localization During Left Atrial Ablation for Atrial Fibrillation

Intracardiac Ultrasound During Left Atrial Ablation for Atrial Fibrillation.u2002Background: Esophageal injury during left atrial ablation is associated with a significant risk of mortality and morbidity. There are no validated approaches to reduce injury outside of avoidance, a strategy critically dependent on a precise understanding of the esophageal anatomy and location. Intracardiac ultrasound (ICE) can provide a real‐time assessment of the esophagus during ablation. We hypothesized that ICE can accurately define esophageal anatomy and location to enhance avoidance strategies during ablation.

The Diagnostic Evolution of the Cardiac Implantable Electronic Device: The Implantable Monitor of Ischemia

The term evolution refers to a process of growth, development, or formation. The foundation of evolution is the accumulation of prior successes or failures that have ultimately directed the process. Fundamental to the practice of electrophysiology has been the technology evolution of the cardiac implantable electronic device. In 1958, Rune Elmquist developed the first implantable cardiac pacemaker that was implanted by Åke Senning.1 This device was strictly used for therapy. It delivered an electrical stimulus at a rate of 70–80 beats per minute with a pulse amplitude of 2 V and a width of 1.5 mV. Although the first device failed almost immediately and the second one only lasted approximately 6 weeks, Arne Larson, the first patient to receive them, lived another 43 years and survived to have received over 20 devices of various sizes and technologies.2 The success of the implantable cardiac pacemaker also prompted the need for the technology to evolve. The device accurately and reproducibly delivered a set therapy; but without a means to diagnose and respond to intrinsic cardiac conduction, patients exchanged one set of symptoms for another. The diagnostic evolution of pacemakers remains a contemporary area of research and investigation. Even the simplest of modern devices can sense and respond to intrinsic conduction in the atrium and/or ventricle. Some devices automatically determine lead thresholds and adjust energy delivery to optimize battery life or alert the patient if a possible failure has occurred. Pacemakers can diagnose, record, and act on tachyarrhythmias in both the atrium and ventricle (Fig. 1A). For example, in Figure 1B a pacemaker diagnosed the period of time per day the patient was in atrial fibrillation (AF). This patient underwent radiofrequency ablation of his AF and had an abrupt decline in the percentage per day in the arrhythmia. The device diagnostics was influential in the identification of the AF, as well as the response to therapy. A more recent area of diagnostics is that applied to a specific disease state. A natural transition of the technology occurred as the devices were implanted broadly to patients with ischemic and nonischemic left ventricular dysfunction in that they could record and quantify parameters of heart failure. These parameters include heart rate variability, thoracic impedance, and daily activity.3,4 Although the device does

Insights into energy delivery to myocardial tissue during radiofrequency ablation through application of the first law of thermodynamics.

The approach to catheter‐based radiofrequency ablation of atrial fibrillation has evolved, and as a consequence, more energy is delivered in the posterior left atrium, exposing neighboring tissue to untoward thermal injury. Simultaneously, catheter technology has advanced to allow more efficient energy delivery into the myocardium, which compounds the likelihood of collateral injury. This review focuses on the basic principles of thermodynamics as they apply to energy delivery during radiofrequency ablation. These principles can be used to titrate energy delivery and plan ablative approaches in an effort to minimize complications during the procedure.