His Bundle Pacing in Bradycardia and Heart Failure
His Bundle Pacing in Bradycardia and Heart Failure
Participants in this study will either have heart failure (HF) and are scheduled to undergo
 cardiac resynchronization therapy pacemaker (CRT-P) or cardiac resynchronization therapy
 defibrillator (CRT-D) implantation, or have atrioventricular (AV) block and are scheduled to
 undergo dual chamber pacemaker implantation. In this study additional heart rhythm
 measurements will be collected during the implant procedure to better understand how His
 bundle and/or parahisian pacing (HISP) effects electrical conduction in the hearts of
 patients with HF or AV block.

 The hypothesis is that His bundle or parahisian pacing (HISP) may normalize atrioventricular
 (AV) conduction with a narrow combination of the Q wave, R wave and S wave (QRS complex) in
 functional bundle branch block or conduction delay in patients with heart failure (HF).
Inclusion Criteria:

 HF Group

 -  Recommended to undergo CRT-P or CRT-D implantation

 -  LBBB, RBBB or IVCD with a QRS duration > 120 ms

 -  LVEF ≤ 35%

 AV Block Group

 -  Recommended to undergo dual chamber pacemaker implantation

 -  Second or third degree AV block

 Exclusion Criteria:

 -  Age < 18 years

 -  Pregnant