EP Lab Digest - May 2008 - (Page 61)

MAY 2008 ECG 101 3. Braunwald E, Libby P, Bonow R, et al. Braunwald’s Heart Disease, A Textbook of Cardiovascular Medicine, Eighth Edition. Copyright 2007 by Saunders, An Imprint of Elsevier. 4. Crawford MH, Bernstein SJ, Deedwania PC, et al. ACC/AHA Guidelines for Ambulatory Electrocardiography: Executive Summary and Recommendations. Circulation 1999;100(8):886893. 5. Krahn AD, Klein GJ, Skanes AC, Yee R. Insertable loop recorder use for detection of intermittent arrhythmias. Pacing Clin Electrophysiol 2004;27(5):657-664. 61 ventricular complexes. Importantly, the rhythms recorded during patient-reported symptoms are selected and displayed. This helps the clinician to identify whether the symptoms may be related to a change in rate or rhythm. Clinically, a Holter monitor is most useful in evaluating a patient who is having frequent or daily symptoms that may be due to an abnormal cardiac rhythm. It can also be helpful in identifying the frequency of ventricular ectopy in a patient with ischemic or nonischemic cardiomyopathy. It is important, however, to remember that many of the findings from Holter monitors, such as premature atrial or ventricular complexes, may not be clinically significant in an otherwise healthy patient, so clinical correlation is necessary for proper evaluation. recognize their presyncopal symptoms and promptly activate their device prior to losing consciousness. Since the device is to be worn for a longer time, the number of ECG vectors is typically limited to one or two, and the signal quality can be less consistent than with a Holter. The ideal scenario for an event recorder is a patient who is symptomatic but not on a daily basis, is willing and capable of wearing the monitoring device for an extended period of time, and is able to activate the device with the onset of symptoms. In these situations, the diagnostic yield of event recorders is quite high with minimal risk to the patient. improved. Proper selection and use of these devices has led to a significant improvement in our overall ability to identify and treat heart rhythm disturbances. References 1. Holter NJ. New method for heart studies: Continuous electrocardiography of active subjects over long periods is now practical. Science 1961;134:1214-1220. 2. Bailey JJ, Berson AS, Handelsman H, Hodges M. Utility of current risk stratification tests for predicting major arrhythmic events after myocardial infarction. J Am Coll Cardiol 2001;38(7):1912-1915. Implantable Loop Recorders Implantable loop recorders are ECG recording devices about the size of a small pack of chewing gum that are implanted just under the skin in the chest. These devices can provide recordings for an extensive period of time, often one to two years. The data is recorded in a loop-like fashion similar to event recorders, and data is again permanently stored as a result of patient or automatic triggering.Typically, a patient can activate the device to store data by passing a small magnetic activator over it.With an implantable loop recorder, usually a much greater preceding period of time (often up to a half hour) is continuously maintained and stored when triggered by the patient. Therefore, patients who have a syncopal event could activate the device even after waking and still capture the culprit rhythm. In the office, a programmer is used to retrieve the stored event data. The main advantage of an implantable loop recorder is that it provides monitoring for such an extended duration and allows the patient a longer period to activate the device. Although it is surgically implanted, it remains minimally invasive with very low complication rates.The signal quality is tested prior to implantation, and tends to be more consistent than with external leads. Overall, it has significantly increased the diagnostic efficacy of ambulatory monitoring. After the diagnosis is made, the device can be explanted on an outpatient basis. Event Recorders For many patients, symptoms are not frequent enough to be caught on a Holter monitor that is worn for only one or two days. An event recorder can provide ECG readings for up to an entire month. ECG leads are again placed on a patient’s chest and then connected by wire to a recorder that is typically the size of a pager. The device will continuously monitor data from the ECG tracings, but only maintains data from a specified period of time, typically the last 30 to 60 seconds.This data is continuously updated in a loop-like fashion. Data is selected to be saved by one of two mechanisms — patient-triggered or automatically triggered events. When patients experience symptoms, they are instructed to push a button that will trigger the device to store the current rhythm as well as data from the short period before and after the event.Alternatively, when the ECG meets programmed criteria in the device (such as a rapid or slow heart rate), the device will be automatically triggered to store the current data. Once data is stored, it can be uploaded to a monitoring center by telephone.This allows the timely identification of potentially dangerous rhythm disturbances before the end of the entire monitoring period. The main advantage of an event recorder over a Holter monitor is that it provides monitoring for a longer period of time, which can significantly improve diagnostic yield. It remains non-invasive and is a lightweight apparatus. Unlike a Holter, however, all data is not permanently stored unless triggered by the patient or the device’s preset parameters. If a patient is unable or forgets to activate the device following an event, the data will not be stored unless it meets the programmed criteria for automatic triggering. Therefore, patients being evaluated for syncope are asked to Summary Ambulatory ECG monitoring is a safe and effective means of monitoring a patient’s heart rhythm on an outpatient basis.There are several different methods of monitoring available, and proper selection is dependent on the clinical scenario being evaluated.With the development of longer term monitoring techniques, the diagnostic yield to determine arrhythmic etiologies (or lack thereof) has significantly http://www.archenterprises.com/ep-catheter-recycling.html http://www.archenterprises.com/ep-catheter-recycling.html

Table of Contents Feed for the Digital Edition of EP Lab Digest - May 2008

EP Lab Digest - May 2008 Is There an Under-Referral of Women for Atrial Fibrillation Ablation? A Hybrid Approach to the Cure of Atrial Fibrillation Contents Letter from the Editor Spotlight Interview: University of Michigan Health System 10-Minute Interview: Amit J. Shanker, MD Modular EP Units: Are They Possible? One Hospital’s Experience All About My Job: Technician Supervisor (New Column!) Alcohol Septal Ablation in the Cath Lab: What is it All About? About the Canadian Heart Rhythm Society: Interview with Martin J. Gardner, MD, FRCP(C), FACC Email Discussion Group: May 2008 Second Annual Salary Survey My First Year in Electrophysiology: What Have I Got Myself Into? Highlight on Technology: Video-Audio Integration for the EP Lab On the Horizon: A New Remote Catheter Manipulation System Striving for Excellence in the Care of Cardiac Patients Five Reasons to Participate with a Professional Organization Suspected Shunting of Defibrillation Energy in the EP Lab Can Digital Music Players Cause Interference with Implantable Devices? ECG 101: Ambulatory ECG Monitoring Events Calendar Industry News and Products Classifieds Advertisers Index

EP Lab Digest - May 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.