The goal of this observational study is to learn more about whether or not the use of heart ultrasound during pacemaker implantation is helpful. The main questions this aims to answer are:

1. Does this help the doctors with figuring out the wire location during implantation?
2. Does this reduce the wire placement procedure time?
3. Does this reduce the x-ray imaging time during the procedure?

Participants will be asked to:

1. Have a physical exam and Echocardiogram (ECG) at initial visit, 2 weeks post implant, and 3 months post implant.
2. Have a urine pregnancy test (if applicable)
3. Have a heart ultrasound during implant procedure
4. Answer questions related to heart failure symptoms to see what stage of heart failure is present
5. Have device interrogation (a wand placed over the chest to see that the device is working properly) at a visit 2 weeks post implant and at 3 months post implant.

The EC-LBBAP study is a prospective, single-enter, observational research study. The study team will identify all patients who satisfy the inclusion and exclusion criteria. The study team will evaluate the feasibility and success rates of echocardiogram guided LBBAP lead implantation.

Eligible patients will undergo LBBAP using Medtronic 3830 lead and C315His sheath. LBBAP will be confirmed at implant using left bundle potentials recorded from the lead, ECG morphology during unipolar and bipolar pacing, peak Left Ventricular Pacing (LV) activation time and lead depth in the 2D transthoracic echo at implant.

During implant procedure, transthoracic echo windows will be identified and documented: Parasternal short and long axis, apical 2 and 4 chamber views and subcostal views to visualize the proximal interventricular septum. Following venous access using cephalic vein cut-down or ultrasound guided axillary vein access, the lead implantation in the left bundle branch region will be guided by echocardiography.

Retrospectively, the study team will identify 20 consecutive previous patients who satisfy inclusion and exclusion criteria (control patients). Twenty patients will undergo intraprocedural transthoracic echocardiogram via standard practices. An additional 10 patients will undergo intraprocedural transthoracic echocardiogram using a hand-held ultrasound device. The study team will compare the difference in procedural success between case and control patients.

Inclusion Criteria:

• patient with indication for permanent pacemaker or Implantable Cardioverter Defibrillator (ICD) utilizing conduction system pacing lead for bradycardia or cardiac resynchronization therapy
• patient is willing to comply with all study procedures and be available for the duration of the study

Exclusion Criteria:

• Inability to provide informed consent
• pregnant
• enrolled in a concurrent study that may confound the results of this study

Data will not be shared in an identifiable way.

Adverse events were collected during study participation up to final study visit at 3 months post implant.

Patients will be asked about adverse events related to the use of the echocardiography. Only echocardiogram related adverse event will be collected and reported and then assessed if it is procedure related, as well as all-cause mortality and serious adverse events.