32
Treatment
Figure 3. Indications for CRT
a,b
LVEF ≤35%
Patient with cardiomyopathy on GDMT for ≥3 mo or on
GDMT and ≥40 d aer MI, or with implantation of pacing or
defibrillation device for special indications
Continue
GDMT without
implanted device
Evaluate general
health status
Comorbidities and/
or frailty limit survival
with good functional
capacity to <1 y
NYHA Class I
• LVEF ≤30%
• QRS ≥150 ms
• LBBB pattern
• Ischemic
cardiomyopathy
• QRS ≤150 ms
• Non-LBBB
pattern
NYHA Class II
• LVEF ≤35%
• QRS ≥150 ms
• LBBB pattern
• Sinus rhythm
• LVEF ≤35%
• QRS 120–149 ms
• LBBB pattern
• Sinus rhythm
• LVEF ≤35%
• QRS ≥150 ms
• Non-LBBB
pattern
• Sinus rhythm
• QRS ≤150 ms
• Non-LBBB
pattern
NYHA Class III
& Ambulatory
Class IV
• LVEF ≤35%
• QRS ≥150 ms
• LBBB pattern
• Sinus rhythm
• LVEF ≤35%
• QRS 120–149 ms
• LBBB pattern
• Sinus rhythm
• LVEF ≤35%
• QRS ≥150 ms
• Non-LBBB
pattern
• Sinus rhythm
• LVEF ≤35%
• QRS 120-149 ms
• Non-LBBB
pattern
• Sinus rhythm
Special CRT
Indications
• Anticipated to
require frequent
ventricular
pacing (>40%)
• AF, if ventricular
pacing is required
and rate control
will result in near
100% ventricular
pacing with CRT
Evaluate NYHA
clinical status
Acceptable
noncardiac health
a
Colors correspond to colors in the ACCF/AHA classification of recommendations (see pages 58–59).
b
Benefit for NYHA class I and II patients has been shown in CRT-D trials, and while patients may not experience
immediate symptomatic benefit, late remodeling may be avoided along with long-term HF consequences. ere are no
trials that support CRT-pacing (without ICD) in NYHA class I and II patients. us, it is anticipated these patients
would receive CRT-D unless clinical reasons or personal wishes make CRT-pacing more appropriate. In patients who
are NYHA class III and ambulatory class IV, CRT-D may be chosen but clinical reasons and personal wishes may
make CRT-pacing appropriate to improve symptoms and quality of life when an ICD is not expected to produce
meaningful benefit to survival.
