The purpose of this study is to determine if patients with heart failure (HF, meaning a weak heart) with left ventricular ejection fraction (LVEF) ≤ 50% and with an abnormal heart beat can benefit from having pacemaker leads placed in a different location in the heart. We know that people with a weak heart and an abnormal heart beat can benefit from having a pacemaker. Participants in this study will be randomly assigned (like flipping a coin) to one of two treatments (A or B), both of which are standard of care heart pacing treatments:
A. Pacing the heart from two locations in the left ventricle (lower left chamber of the heart)
B. Pacing the heart from one of two other places in the heart (the "His" or the left bundle branch)

The purpose of this study is to compare side by side these two treatments and evaluate if one is better than the other.

This study is enrolling subjects who need a pacemaker implant for a heart rhythm disorder. A pacemaker is a device implanted under the skin in the upper chest, and is designed to send electrical signals to tell the heart to squeeze (contract) through wires called leads. A conventional pacemaker has a lead placed in the right ventricle (lower chamber of the heart) which is referred to as ventricular pacing. This study will investigate conduction system pacing which is pacing from the part of the ventricle that normally carries electricity through the heart. The specific name for this part of the ventricle is the left bundle branch block area. The heart's conduction system initiates impulses that tells the heart muscle to contract in a coordinated fashion. This study will use the Solia S lead, which is considered investigational, meaning it is not yet approved by the Food and Drug Administration (FDA) for conduction system pacing. The Solia S lead is approved for ventricular pacing.

Participation in this study will last about one year and include 4-5 visits, some of which may be done virtually. The study involves collecting data from your pacemaker implant, Solia S placement, completing questionnaires, electrocardiogram, medical history and medications.

Risks include those associated with the pacemaker implant procedure such as potentially longer implant time, a tear in the interventricular septum (the wall separating the lower chambers of the heart) or unsuccessful lead placement. Other study related risks may include the risk of loss of confidentiality, risks of answering a questionnaire or unknown risks. There may be no benefit to you but the information learned may benefit others in the future who need conduction system pacing.