Ultra-High Frequency - Electrocardiogram (UHF-ECG) for the Diagnosis of Ventricular Electrical Dyssynchrony (VED)

Inclusion Criteria:

* Adults with bradycardia or heart failure scheduled for first time pacemaker implant (including CRT/CSP) with one of the following: Bradycardia with ventricular synchrony and QRS duration \<= 110 ms, Bradycardia with LBBB, Bradycardia with RBBB, Bradycardia with other IVCD necessitating intervention, or Heart failure with LBBB
* Understands the nature of the study and is willing to comply with all study requirements.
* Provides written informed consent.
* A negative pregnancy test prior to the procedure for participants of child-bearing potential.

Exclusion Criteria:

* Complete AV block (3rd-degree AV block) without a stable escape rhythm or other circumstances where there is no measurable QRS.
* Subjects with a previous or current pacemaker or defibrillator implant.
* Anatomical or other conditions that may make a 12-lead ECG difficult to obtain, such as an allergy to components of the ECG pads, burns, open wounds, etc.
* Currently enrolled in another investigational device or drug trial that has not completed the active treatment phase and/or would conflict with this study.
* Other co-morbid condition(s) that could limit the participant's ability to participate in the study or to comply with study requirements or impact the scientific integrity of the study.