Thursday, September 2, 2010

The Utility of Ambulatory Electrocardiographic Monitoring for Detecting Silent Arrhythmias and Clarifying Symptom Mechanism in an Elderly Urban Popula


Citation : Kathleen T. Hickey, James Reiffel, Robert R. Sciacca, William Whang, Angelo Biviano, Maurita Baumeister, Carmen Castillo, Jyothi Talathothi, Hasan Garan.The Utility of Ambulatory Electrocardiographic Monitoring for Detecting Silent Arrhythmias and Clarifying Symptom Mechanism in an Elderly Urban Population with Heart Failure and Hypertension: Clinical Implications .JAFIB.2010 May;Volume 1 Issue(12): 663-674.

Background: Atrial and ventricular tachyarrhythmias, including atrial fibrillation (AF) as well as bradyarrhythmias have been well documented in elderly and generally symptomatic patients with heart failure (HF) and/or hypertension (HTN), most often using 24 hour continuous monitoring. However, the frequency of these arrhythmias, including silent as well as symptomatic, as assessed by more prolonged monitoring, the relationship between symptoms in patients with HF and/or HTN and an underlying arrhythmia, and the association of arrhythmias including those that are silent with subsequent cardiac events has not been well defined in patients 65 years or older with HF and other cardiovascular risk factors. Importantly in such patients, AF, even if symptomatic, would yield a CHADS2 score indicative of anticoagulation.

Objective: A pilot study to assess the potential value of 2 weeks of out-patient, transtelephonic cardiac auto-triggered loop-monitoring for detecting arrhythmias, assessing their relationship to symptoms, predicting the risk of subsequent cardiac events, and determining if they result in therapy in an elderly, urban population living with HF.

Methods: Fifty-four subjects with a history of systolic HF and/or HTN consented to wear an auto triggered cardiac loop monitor for 2 weeks. This device captures EKG data, including silent and symptomatic arrhythmias. Subjects were requested to transmit data once daily as well as to transmit if they were symptomatic to determine if an underlying dysrhythmia was present.

Results: Mean age was 73 ± 6 years with 59% were female, 74% Hispanic, 22% black, and 4% white/other. All subjects had HF and 94% had HTN; all were in sinus rhythm at the time of enrollment. From the cardiac monitoring, 72% demonstrated ectopic atrial and ventricular activity. In addition, 1 paroxysmal episode of AF was documented, 3 people had significant non-sustained ventricular tachycardia that contributed to the placement of an internal cardioverter defibrillator (ICD), and 4 individuals underwent subsequent placement of a pacemakers for severe bradycardia/heart block (per established guidelines). The relationship between arrhythmia and symptoms was weak. These events would have otherwise gone undetected and untreated. During follow-up, 15 subjects (28%) had significant cardiac events, including one patient with a non ST segment myocardial infarction (NSTEMI) infarct due to undetected and untreated AF and one patient with symptomatic 2:1 atrial flutter. The AF and flutter patients all had CHADS2 scores appropriate for initiation of anticoagulation.

Conclusion: A substantial proportion of subjects exhibited arrhythmias during monitoring, cardiac events during follow-up and consequent therapy. This approach to arrhythmia screening appears to have sufficient merit to warrant further study.

Electrophysiological Changes of the Atrium in Patients with Lone Paroxysmal Atrial Fibrillation


Citation : Osmar Antonio Centurion, Shojiro Isomoto, Akihiko Shimizu.Electrophysiological Changes of the Atrium in Patients with Lone Paroxysmal Atrial Fibrillation .JAFIB.2010 May;Volume 1 Issue(12): 656-662.

Introduction: Paroxysmal atrial fibrillation (PAF) is a common arrhythmia, and it is associated with various cardiac conditions. On the other hand, lone PAF has no identifiable underlying cause, and can occur any time for no apparent reason. The underlying causes may modify the electrophysiological properties of the atrium in different ways and extent. However this setting may be different in patients with lone PAF. We sought to investigate the atrial electrophysiological properties in lone PAF.
Material and Methods: This study included 62 control subjects (Control group) and 58 patients with lone PAF (LAF group). The following atrial vulnerability parameters induced by programmed atrial stimulation were assessed and quantitatively measured: 1) the atrial effective refractory period (ERP), 2) the atrial conduction delay (CD) zone, and 3) the maximum CD.
Results: The mean atrial ERP of the Control group was 215±29 ms, and that of LAF group was 208±28 ms, p<0.05. The mean atrial CD zone of the LAF group was (50±28 ms) significantly greater than that of controls (34±22 ms) (p<0.01). The mean maximum CD of the LAF group (62±29 ms) was also significantly greater than that of controls (43±20 ms) (p<0.01).
Conclusions: There is a greater conduction delay of the atrium and shorter refractoriness in patients with lone PAF. Patients without underlying causes for the development of PAF exhibit abnormalities in the electrophysiological properties of the atrium.
Key words: Atrial vulnerability. Atrial refractory period. Atrial conduction time. Atrial fibrillation. Atrial conduction delay.

Saturday, April 10, 2010

Determining esophageal anatomy with a new electroanatomical mapping system Short Title – Esophageal anatomy during PVI Diego Chemello MD, Imad Ham


Citation : Diego Chemello, Imad Hameedullah, Anandaraja Subramanian, Eugene Downar.Determining esophageal anatomy with a new electroanatomical mapping system .JAFIB.2010 March;Volume 1 Issue(11): 653-655.

A 53-year-old woman with symptomatic paroxysmal atrial fibrillation was referred for pulmonary vein isolation (PVI). After obtaining access to left atrium (LA) and placement of catheters by standard technique, a high-resolution electroanatomical map of the LA and the pulmonary veins (PVs) was constructed using a map catheter (EZ Steer® Bi-directional catheter, Biosense Webster, Inc. Diamond Bar, USA) and the Carto® 3 System (Biosense-Webster Inc. Diamond Bar, USA) in the Fast Anatomical Mapping (FAM) mode.

An Update on the Energy Sources and Catheter Technology for the Ablation of Atrial Fibrillation


Citation : Pawan K. Arora, James C. Hansen, Adam D. Price, Josef Koblish, Boaz Avitall.An Update on the Energy Sources and Catheter Technology for the Ablation of Atrial Fibrillation .JAFIB.2010 March;Volume 1 Issue(11): 632-652.

The ablation of atrial fibrillation (AF) is an area of intense research in cardiac electrophysiology. In this review, we discuss the development of catheter-based interventions for AF ablation. We outline the pathophysiologic and anatomic bases for ablative lesion sets and the evolution of various catheter designs for the delivery of radiofrequency (RF), cryothermal, and other ablative energy sources. The strengths and weaknesses of various specialized RF catheters and alternative energy systems are delineated, with respect to efficacy and patient safety.

Atrial Fibrillation in Athletes - The Story Behind The Running Hearts


Citation : Shaolong Li, Zhihui Zhang, Benjamin J. Scherlag, Sunny S. Po.Atrial Fibrillation in Athletes - The Story Behind The Running Hearts .JAFIB.2010 March;Volume 1 Issue(11): 626-631.

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice but the mechanisms underlying the initiation and maintenance of AF are yet to be clarified. It is well-known that regular exercise is beneficial to health and reduces the risks of cardiovascular diseases. However, recent studies suggest that long-term endurance exercise, including running [1], swimming, rowing [2] and cycling [3], or vigorous competitive sports may increase the incidence of AF in these athletes. This review article is intended to provide a summary of the possible links between exercise and AF.

Current Perspectives: Rheumatic Atrial Fibrillation


Citation :Bhima shankar P.R, Hygriv Roa B, Jaishankar S, Narasimhan C.Current Perspectives: Rheumatic Atrial Fibrillation .JAFIB.2010 March;Volume 1 Issue(11): 616-625.

AF is a common arrhythmia associated with large burden of morbidity and mortality. In areas with a high prevalence of rheumatic heart disease, valve disease is the most common substrate for the occurrence of AF and this problem assumes greater importance because the resulting escalation in morbidity and mortality involves relatively younger population. As is true of the general population, the prevalence of AF in patients with rheumatic mitral valve disease (RMVD) increases with advancing age.

Effect of Statins in Preventing Postoperative Atrial Fibrillation Following Cardiac Surgery


Citation : Liang Yin, Zhinong Wang, Yifeng Wang, Guangyu Ji, Zhiyun Xu.Effect of Statins in Preventing Postoperative Atrial Fibrillation Following Cardiac Surgery .JAFIB.2010 March;Volume 1 Issue(11): 609-615.

Background Postoperative occurrence of atrial fibrillation (AF) has been associated with less favorable outcomes in patients undergoing cardiac surgery and may result in increased post-operative morbidity and mortality.

Objectives A systematic review and meta-analysis of published studies were conducted to verify the effect of statins in the occurrence of AF after cardiac surgery.

Methods Using the Medline database, the Cochrane clinical trials database and online clinical trial databases, we reviewed all randomized controlled trials (RCTs) and observational studies examining the risk factors of occurrence AF after CABG. We searched for literature published April 2009 or earlier.

Results Our review identified 6 studies (observational studies), involving 10165 patients, that examined the effect of statins on the occurrence of AF following cardiac surgery. Conflict from most of articles, the overall outcomes suggest that the statins group did not have a significant decrease in the occurrence of AF following cardiac surgery (P = 0.19).

Conclusions The preoperative medication of statins showed no significant decrease in AF occurrence following cardiac surgery in the Meta-analysis result. A more prospective studies and researches are needed to explore and demonstrate the real effect of statins on the postoperative AF.