Perspective:

The following are 10 new or modified recommendations for device therapy:

1. Cardiac resynchronization therapy (CRT) is indicated for patients with an ejection fraction (EF) ≤35%, sinus rhythm, left bundle branch block (LBBB), QRS ≥150 ms, and New York Heart Association (NYHA) class II-IV symptoms.

2. CRT is reasonable for patients with an EF ≤35%, sinus rhythm, left bundle branch block (LBBB), QRS 120-149 ms, and NYHA class II-IV symptoms.

3. CRT is reasonable for patients with an ejection fraction (EF) ≤35%, sinus rhythm, non-LBBB pattern, QRS ≥150 ms, and New York Heart Association (NYHA) class III-IV symptoms.

4. CRT is reasonable for patients with an EF ≤35% and atrial fibrillation if the patient requires ventricular pacing or otherwise meets CRT criteria.

5. CRT is reasonable for patients with an EF ≤35% who are undergoing device placement and will need >40% ventricular pacing.

6. CRT may be considered for patients with an EF ≤30%, ischemic cardiomyopathy, sinus rhythm, LBBB, QRS ≥150 ms, and NYHA class I symptoms.

7. CRT may be considered for patients with an EF ≤30%, sinus rhythm, a non-LBBB pattern, QRS 120-149 ms, and NYHA class III-IV symptoms.

8. CRT may be considered for patients with an EF ≤30%, sinus rhythm, a non-LBBB pattern, QRS ≥150 ms, and NYHA class II symptoms.

9. CRT is not recommended for patients with NYHA class I-II symptoms, a non-LBBB pattern, and a QRS <150 ms.

10. CRT is not indicated for patients whose prognosis for survival with good functional capacity is limited to <1 year.