CRT is recommended for patients in sinus rhythm with NYHA class II, NYHA class III, or ambulatory NYHA class IV heart failure symptoms, a LVEF ≤ 35%, and QRS duration ≥ 130 ms because of LBBB (Recommendation Strong, Quality High).

Values and Preferences This recommendation places great value on the inclusion criteria of the landmark CRT trials, the characteristics of the patients enrolled in these trials, and the derived benefit of CRT in patient groups identified in subsequent analyses of these landmark trials.