Thursday, June 18, 2009

Esophageal Dilatation Post – Gastric Banding And Catheter Ablation For Atrial Fibrillation: A Case Report

Citation : Simon Townsend, Andrew James, Nicholas Daunt MBBS, Karen P. Phillips MBBS.Esophageal Dilatation Post – Gastric Banding and Catheter Ablation for Atrial Fibrillation: A Case Report .JAFIB.2009 June;Volume 1 Issue(7): 451-453.

Esophageal injury is a potential serious complication of catheter ablation for atrial fibrillation. We report a case of significant esophageal dilatation following previous laparascopic gastric banding in a patient with permanent atrial fibrillation undergoing a pulmonary vein isolation procedure.

The position of the esophagus was delineated on the integrated CT navigational map and on fluoroscopy by placement of an esophageal thermistor probe. Radiofrequency energy was delivered through an open irrigated tip catheter and titrated to maximum 25W and 40°C for lesions applied to the left atrial posterior wall. Esophageal temperature rises were only seen in association with lesions applied to the right inferior pulmonary vein and energy applications here were limited to avoid esophageal temperatures >38.5°C.

Masquerading Tachycardia

Citation : Yaariv Khaykin MD, Zaev Wulffhart MD, Bonnie Whaley CCT, Atul Verma MD.Masquerading Tachycardia .JAFIB.2009 June;Volume 1 Issue(7): 447-450.

Mrs. BW is a 69 year old previously well woman with history of palpitations. Extensive workup showed no evidence of structural heart disease. Her baseline ECG was unremarkable. She was clinically documented to have narrow complex tachycardia. In tachycardia her ECG showed brief bursts of ectopic atrial activity with “saw-tooth” appearance in the inferior leads (Figure 1, Panel A) alternating with lesser amplitude p-waves positive in the inferior leads and in V1 (Figure 1, Panel B). During electrophysiology study a quadripolar catheter was placed at the right ventricular apex, a decapolar catheter in the coronary sinus, a duodecapolar catheter around the tricuspid annulus and a quadripolar catheter at the His bundle position.

The Phrenic Nerve and Atrial Fibrillation Ablation Procedures

Citation : Jennifer A. Mears, BS, Nirusha Lachman, PhD, Kevin Christensen, Samuel J. Asirvatham, MD, FACC, FHRS.The Phrenic Nerve and Atrial Fibrillation Ablation Procedures .JAFIB.2009 June;Volume 1 Issue(7): 430-446.

Radiofrequency ablation is increasingly used as an option to optimally manage patients with symptomatic atrial fibrillation. Presently, ablationists strive to improve success rates, particularly with persistent atrial fibrillation, while simultaneously attempting to reduce complications. A well-recognized complication with atrial fibrillation ablation is injury to the phrenic nerve giving rise to diaphragmatic paresis and patient discomfort.

Phrenic nerve damage may occur when performing common components of atrial fibrillation ablation including pulmonary and superior vena caval isolation. The challenge for ablationists is to successfully target the arrhythmogenic substrate while avoiding this complication. In order to do this, a thorough knowledge of phrenic nerve anatomy, points in the ablation procedure where nerve damage is more likely, and an understanding of the presently utilized techniques to avoid this complication is required.

In addition, when this complication does arise, prompt recognition of its occurrence, knowledge of the natural history, and available methods for management are needed.

In this review, we discuss the underlying anatomic principles, techniques of avoiding phrenic nerve damage, and presently available methods of diagnosing and managing this complication.

Atrial Fibrillation Complicating Congestive Heart Failure: Electrophysiological aspects and its Deleterious effect on Cardiac Resynchronization therap

Citation : Osmar Antonio CenturiĆ³n, MD, PhD, FACC.Atrial fibrillation complicating congestive heart failure: Electrophysiological aspects and its deleterious effect on cardiac resynchronization therapy .JAFIB.2009 June;Volume 1 Issue(7): 417-429.

More successful recognition and treatment of cardiovascular risk factors and diseases continues to decrease mortality and increase the proportion of elderly population. Therefore, there are more people with increased risk of developing heart failure and atrial fibrillation in the course of their lives. Atrial fibrillation (AF) can complicate the course of congestive heart failure (HF) leading to acute pulmonary edema. The prevalence of AF, in patients with heart failure, increases with the severity of the disease, reaching up to 40% in advanced cases. In these HF patients, AF is an independent predictor of morbidity and mortality increasing the risk of death and hospitalization. Despite the excellent results obtained with different drugs, the optimal medical treatment can fail in the intention to improve symptoms and quality of life of patients with severe HF. Thus, the necessity to use cardiac devices emerges facing the failure of optimal medical treatment in order to achieve hemodynamic improvement and correction of the physiopathological alterations. Cardiac resynchronization therapy (CRT) can reduce the interventricular and intraventricular mechanical dissynchrony in HF patients. It has been shown that CRT increases the left ventricular filling time, decreases septal disquinesia, mitral regurgitation, and left ventricular volumes allowing a hemodynamic improvement. However, the development of AF in this setting can avoid the beneficial effects of CRT. Therefore, this manuscript will review the available data on this topic to determine what can be done in the event of an AF complicating congestive HF in CRT patients.

Atrial Remodeling and Atrial Fibrillation: Mechanistic Interactions and Clinical Implications

Citation : Bandar Al Ghamdi, MD, Walid Hassan, MD, FACP, FACC, FCCP, FAHA.Atrial Remodeling And Atrial Fibrillation: Mechanistic Interactions And Clinical Implications .JAFIB.2009 June;Volume 1 Issue(7): 395-416.

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice. The prevalence of AF increases dramatically with age and is seen in as high as 9% of individuals by the age of 80 years. In high-risk patients, the thromboembolic stroke risk can be as high as 9% per year and is associated with a 2-fold increase in mortality. Although the pathophysiological mechanism underlying the genesis of AF has been the focus of many studies, it remains only partially understood. Conventional theories focused on the presence of multiple re-entrant circuits originating in the atria that are asynchronous and conducted at various velocities through tissues with various refractory periods. Recently, rapidly firing atrial activity in the muscular sleeves at the pulmonary veins ostia or inside the pulmonary veins have been described as potential mechanism,. AF results from a complex interaction between various initiating triggers and development of abnormal atrial tissue substrate. The development of AF leads to structural and electrical changes in the atria, a process known as remodeling. To have effective surgical or catheter ablation of AF good understanding of the possible mechanism(s) is crucial. Once initiated, AF alters atrial electrical and structural properties that promote its maintenance and recurrence. The role of atrial remodeling (AR) in the development and maintenance of AF has been the subject of many animal and human studies over the past 10-15 years. This review will discuss the mechanisms of AR, the structural, electrophysiologic, and neurohormonal changes associated with AR and it is role in initiating and maintaining AF. We will also discuss briefly the role of inflammation in AR and AF initiation and maintenance, as well as, the possible therapeutic interventions to prevent AR, and hence AF, based on the current understanding of the interaction between AF and AR.

Evolution of Paroxysmal Atrial Fibrillation to Persistent or Permanent Atrial Fibrillation: Predictors of Progression

Citation : Jayasree Pillarisetti, Akshar Patel, Kenneth Boc, Sudharani Bommana, Youssef Sawers, Subbareddy Vanga, Hari Sayana, Warren Chen, Jayanth Nath, James Vacek, Dhanunjaya Lakkireddy. Evolution of Paroxysmal Atrial Fibrillation to Persistent or Permanent Atrial Fibrillation: Predictors of Progression .JAFIB.2009 June;Volume 1 Issue(7): 388-394.

Introduction – Paroxysmal atrial fibrillation (PAF) eventually progresses to persistent and permanent AF. The predictors of progression from PAF to persistent and permanent AF are poorly understood.
Methods – Electronic medical records of 437 patients with PAF were reviewed in a retrospective cohort study. Patients were followed in time and progression to persistent/permanent AF was recorded. Demographic, clinical and echocardiographic information was collected. A logistic regression analysis was performed to identify predictors of progression to persistent/permanent AF.
Results – Over a mean duration of 57.3±55.9 months, 32.4% of patients progressed to persistent/permanent AF. Mean age of the population was 67.9±13.4 years with 57% males and 92% Caucasian. Univariate analysis identified higher body higher mass index (BMI), cardiomyopathy, diabetes, valvular heart disease (VHD), larger left atrial size (LA) and higher pulmonary artery pressure as predictors of progression. Multivariate logistic regression analysis larger left atrial size (OR 1.46, CI 1.05-2.04, P 0.002), cardiomyopathy (OR 2, CI 1.1- 3.3, P 0.003), and moderate to severe valvular heart disease (OR 3.3, CI 1.4-5, P 0.008) as significant predictors of progression to persistent/permanent AF.
Conclusion – Our study shows that PAF patients with larger LA, valvular heart disease and cardiomyopathy predict progression of PAF to persistent/permanent AF. Higher BMI and cardiomyopathy predicted progression to persistent AF while larger LA size and VHD predicted progression to permanent AF.