The objective of this clinical study was to evaluate the impact of Multipoint Pacing (MPP) and SyncAV programming on ventricular electrical activation time and activation sequence using noninvasive electrocardiographic imaging (ECGi) in patients receiving cardiac resynchronization therapy (CRT).

Inclusion Criteria:

• Patients previously implanted with a SyncAV and MPP-enabled Abbott Quadripolar CRT pacing system
• Patient must be > 18 years of age, able to provide informed consent and willing to comply with study requirements
• Sinus (or atrial paced) rhythm with intact AV conduction with PR interval ≤ 250 ms
• Patient has documented Left Bundle Branch Block (LBBB)

Exclusion Criteria:

• Resting heart rate > 100 bpm
• AV Block (1st degree with PR> 250 ms, 2nd or 3rd degree)
• Documented persistent atrial tachycardia or atrial fibrillation at the moment of enrollment or patients not likely to remain in sinus (or atrial paced) rhythm for the duration of the study
• Recent (< 3 months) myocardial infarction, ablation, electrolyte imbalance, or any condition within the last 90 days that would contraindicate for CRT programming changes in the opinion of the investigator
• Women who are pregnant or plan to become pregnant during the study course

The intended population for this clinical investigation consisted of patients over the age of 18 years who have been previously implanted with an Abbott CRT device capable of SyncAV and MultiPoint Pacing. This clinical investigation enrolled male and female subjects from the general heart failure population. Subjects must have met all eligibility criteria and provide written informed consent prior to conducting any investigation-specific procedures not considered standard of care.