Table 3

Summary of relevant international guidance

DevicePatient groupRecommendationReference
CRT-PLVEF ≤35%, NYHA class II, III, ambulatory class IV:35
QRS≥150 ms with LBBBClass I Level A
QRS≥150 ms without LBBBClass IIa Level B
QRS ≥120 to <150 ms with LBBBClass I Level B
QRS ≥120 to <150 ms without LBBBClass IIb Level B
ICDLVEF ≤35%, NYHA class II–III2
IschaemicClass I Level A
Non-ischaemicClass I Level B
CRT-DPatients in whom CRT-P is indicated and ICD is plannedClass I Level A35
Patients with indicators of better prognosis and/or ischaemic heart diseaseClass IIa Level B
  • CRT-D, cardiac resynchronisation therapy pacemaker with defibrillation therapy; CRT-P, cardiac resynchronisation therapy pacemakers; ICD, implantable cardioverter defibrillators; LBBB, left bundle branch block; NYHA, New York Heart Association.