Diagnosis and Treatment
Figure 2. Indications for Cardiac Resychronization Therapy
Patient with cardiomyopathy on GDMT for ���3 mo or on
GDMT and ���40 d after MI, or with implantation of pacing or
defibrillation device for special indications
LVEF ���35%
Evaluate general
health status
Comorbidities and/
or frailty limit survival
with good functional
capacity to <1 y
Continue
GDMT without
implanted device
Acceptable
noncardiac health
Evaluate NYHA
clinical status
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
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
������ LVEF ���35%
������ QRS ���150 ms
������ Non-LBBB
pattern
������ Sinus rhythm
������ LVEF ���35%
������ QRS 120-149 ms
������ Non-LBBB
pattern
������ Sinus rhythm
Colors correspond to the class of recommendations in the ACCF/AHA Table (pages 18-19).
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. There
are no trials that support CRT-pacing (without ICD) in NYHA class I and II patients. Thus, 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.
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