Recommendations for Cardiac Resynchronization Therapy in Patients With Severe Systolic Heart Failure
Class I
(1) For patients who have LV ejection fraction (LVEF) less than or
equal to 35%, a QRS duration greater than or equal to 0.12 seconds, and sinus rhythm, CRT with or without an ICD is indicated for the treatment of New York Heart Association (NYHA) functional Class III or ambulatory Class IV heart failure symptoms with optimal recommended medical therapy.
Class IIa
(1) For patients who have LVEF less than or equal to 35%, a QRS
duration greater than or equal to 0.12 seconds, and atrial fibrillation, CRT with or without an ICD is reasonable for the treatment of NYHA functional Class III or ambulatory Class IV heart failure symptoms on optimal recommended medical therapy.
(2) For patients with LVEF less than or equal to 35% with NYHA
functional Class III or ambulatory Class IV symptoms who are receiving optimal recommended medical therapy and who have frequent dependence on ventricular pacing, CRT is reasonable.
Class IIb
(1) For patients with LVEF less than or equal to 35% with NYHA
functional Class I or II symptoms who are receiving optimal recommended medical therapy undergoing implantation of a permanent pacemaker and/or ICD with anticipated frequent ventricular pacing, CRT may be considered.
Class III
(1) CRT is not indicated for asymptomatic patients with reduced
LVEF in the absence of other indications for pacing.
(2) CRT is not indicated for patients whose functional status and life
expectancy are limited predominantly by chronic noncardiac conditions.)