September 11th, 2012

Updated Rhythm Device Guidelines Clarify and Expand CRT Criteria

A newly released update of 2008 guidelines for device-based therapy of cardiac arrhythmias contains some much-needed clarification about indications for cardiac resynchronization therapy (CRT). The document was developed jointly by the American Heart Association, the American College of Cardiology, and the Heart Rhythm Society.

Highlights of the documents include:

  • The Class 1 recommendation for CRT for patients with systolic heart failure (HF) is now limited to patients with a QRS duration of at least 150 ms but has been expanded to include both patients with NYHA class II symptoms and LBBB patients.
  • A Class IIa recommendation for patients with a QRS duration of 120-149 who otherwise meet the criteria for a Class 1 recommendation.
  • A new Class IIB recommendation for patients with NYHA class I symptoms with LVEF 30% or lower, ischemic HF, sinus rhythm, and LBBB with a QRS duration at least 150 ms.
  • Recommendations from 2008 remain in effect for hypertrophic cardiomyopathy, arrhythmogenic RV  dysplasia/cardiomyopathy, genetic arrhythmias, congenital disease, primary electrical disease, and terminal care.

The document also provides updated information about remote follow-up and monitoring of patients with cardiovascular implantable electronic devices.

“There is growing evidence that patients with the widest, most abnormal looking ECG potentially benefit most compared to patients whose ECG are less abnormal,” said Cynthia M. Tracy, the chair of the writing group, in a press release. She noted that patients with LBBB particularly benefit from CRT.

The authors noted that a separate document under development will define appropriate use criteria and “will help to further interpret the best science and apply it to various clinical scenarios.”

One Response to “Updated Rhythm Device Guidelines Clarify and Expand CRT Criteria”

  1. What about the evidence base for RBBB and the use of qualified action words such as “is reasonable ” and “may be considered”? How do clinicians convey a confident recommendation to patients to undertake a risky procedure, albeit in a high risk clinical milieu?