Indications for Ambulatory Electrocardiography (AECG)

There are numerous potential clinical uses of the 12-lead ECG. The ECG may reflect changes associated with primary or secondary myocardial processes (e.g., those associated with coronary artery disease, hypertension, cardiomyopathy, or infiltrative disorders), metabolic and electrolyte abnormalities, and therapeutic or toxic effects of drugs or devices. Electrocardiography serves as the gold standard for the noninvasive diagnosis of arrhythmias and conduction disturbances, and it occasionally is the only marker for the presence of heart disease.

The recommendations are classified according to the system used by the ACC and AHA. The classification system is as follows:

  • Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is useful and effective.
  • Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment. Class IIa:The weight of evidence/opinion is in favor of usefulness/efficacy. Class IIb:The usefulness/efficacy is less well established by evidence/opinion.
  • Class III: Conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful/effective, and in some cases may be harmful.

Indications for AECG to Assess Symptoms Possibly Related to Rhythm Disturbances
Class I

  1. Patients with unexplained syncope, near syncope, or episodic dizziness in whom the cause is not obvious
  2. Patients with unexplained recurrent palpitation

Class IIb

  1. Patients with episodic shortness of breath, chest pain, or fatigue that is not otherwise explained
  2. Patients with neurological events when transient atrial fibrillation or flutter is suspected
  3. Patients with symptoms such as syncope, near syncope, episodic dizziness, or palpitation in whom a probable cause other than an arrhythmia has been identified but in whom symptoms persist despite treatment of this other cause

Class III

  1. Patients with symptoms such as syncope, near syncope, episodic dizziness, or palpitation in whom other causes have been identified by history, physical examination, or laboratory tests
  2. Patients with cerebrovascular accidents, without other evidence of arrhythmia

Indications for AECG Arrhythmia Detection to Assess Risk for Future Cardiac Events in Patients Without Symptoms From Arrhythmia
Class I
None
Class IIb

  1. Post-MI patients with LV dysfunction (ejection fraction </=40%)
  2. Patients with CHF
  3. Patients with idiopathic hypertrophic cardiomyopathy

Class III

  1. Patients who have sustained myocardial contusion
  2. Systemic hypertensive patients with LV hypertrophy
  3. Post-MI patients with normal LV function
  4. Preoperative arrhythmia evaluation of patients for noncardiac surgery
  5. Patients with sleep apnea
  6. Patients with valvular heart disease

Indications for Measurement of Heart Rate Variability (HRV) to Assess Risk for Future Cardiac Events in Patients Without Symptoms From Arrhythmia
Class I
None
Class IIb

  1. Post-MI patients with LV dysfunction
  2. Patients with CHF
  3. Patients with idiopathic hypertrophic cardiomyopathy

Class III

  1. Post-MI patients with normal LV function
  2. Diabetic subjects to evaluate for diabetic neuropathy
  3. Patients with rhythm disturbances that preclude HRV analysis (ie, atrial fibrillation)

Indications for AECG to Assess Antiarrhythmic Therapy
Class I
To assess antiarrhythmic drug response in individuals in whom baseline frequency of arrhythmia has been characterized as reproducible and of sufficient frequency to permit analysis
Class IIa

  1. To detect proarrhythmic responses to antiarrhythmic therapy in patients at high risk

Class IIb

  1. To assess rate control during atrial fibrillation
  2. To document recurrent or asymptomatic nonsustained arrhythmias during therapy in the outpatient setting

Class III
None
Indications for AECG to Assess Pacemaker and Implantable Cardioverter-Defibrillator (ICD) Function
Class I

  1. Evaluation of frequent symptoms of palpitation, syncope, or near syncope to assess device function to exclude myopotential inhibition and pacemaker mediated tachycardia and to assist in the programming of enhanced features such as rate responsivity and automatic mode switching
  2. Evaluation of suspected component failure or malfunction when device interrogation is not definitive in establishing a diagnosis
  3. To assess the response to adjunctive pharmacological therapy in patients receiving frequent ICD therapy

Class IIb

  1. Evaluation of immediate postoperative pacemaker function after pacemaker or ICD implantation as an alternative or adjunct to continuous telemetric monitoring
  2. Evaluation of the rate of supraventricular arrhythmias in patients with implanted defibrillators

Class III

  1. Assessment of ICD/pacemaker malfunction when device interrogation, ECG, or other available data (chest radiograph and so forth) are sufficient to establish an underlying cause/diagnosis
  2. Routine follow-up in asymptomatic patients

Indications for AECG for Ischemia Monitoring
Class I
None
Class IIa

  1. Patients with suspected variant angina

Class IIb

  1. Evaluation of patients with chest pain who cannot exercise
  2. Preoperative evaluation for vascular surgery of patients who cannot exercise
  3. Patients with known coronary artery disease (CAD) and atypical chest pain syndrome

Class III

  1. Initial evaluation of patients with chest pain who are able to exercise
  2. Routine screening of asymptomatic subjects

Indications for Holter Monitoring (24 – 48 hours)
Traditionally, ambulatory monitoring has been used to determine the cause of palpitations and syncope and, to a lesser degree, to identify ventricular ectopy or nonsustained ventricular tachycardia in patients at potential risk for sudden cardiac death. Atrial fibrillation (AF) has become an increasingly important indication for ambulatory monitoring, predominantly as a tool to monitor the efficacy and safety of pharmacological and nonpharmacological therapies. It is also used to identify asymptomatic AF as a potential source of cryptogenic stroke.
 
 
References:

  1. Crawford MH, Bernstein SJ, Deedwania PC, DiMarco JP, Ferrick KJ, Garson A Jr, Green LA, Greene HL, Silka MJ, Stone PH, Tracy CM, Gibbons RJ, Alpert JS, Eagle KA, Gardner TJ, Gregoratos G, Russell RO, Ryan TH, Smith SC Jr. ACC/AHA Guidelines for Ambulatory Electrocardiography. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the Guidelines for Ambulatory Electrocardiography). Developed in collaboration with the North American Society for Pacing and Electrophysiology. J Am Coll Cardiol. 1999 Sep;34(3):912-48. [Medline]
  2. Zimetbaum P, Goldman A. Ambulatory arrhythmia monitoring: choosing the right device. Circulation. 2010 Oct 19;122(16):1629-36. [Medline]

Created May 18, 2013.

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