Subjects intended to undergo initial (de novo) pacing system implant using the INGEVITY+ lead in the left bundle branch area (LBBA) and a Boston Scientific single or dual- chamber pacemaker (Note: no prior attempted pacing system components);

Subjects who are indicated for and will receive a Boston Scientific pacemaker system (including the single or dual chamber pacemaker and an INGEVITY+ lead in the LBBA location) for one of the following medical conditions:

1. Symptomatic paroxysmal or permanent second- or third-degree AV block,

2. Symptomatic bilateral bundle branch block,

3. Symptomatic paroxysmal or transient sinus node dysfunction with or without associated AV conduction disorders (i.e., sinus bradycardia, sinus arrest, sinoatrial \[SA\] block),

4. Bradycardia-tachycardia syndrome, to prevent symptomatic bradycardia or some forms of symptomatic tachyarrhythmias,

5. Neurovascular (vasovagal) syndromes or hypersensitive carotid sinus syndromes,

6. Adaptive-rate pacing for patients exhibiting chronotropic incompetence and who may benefit from increased pacing rates concurrent with increases in minute ventilation and/or level of physical activity.

   Dual-chamber and atrial tracking modes are also indicated for patients who may benefit from maintenance of AV synchrony. Dual chamber modes are specifically indicated for treatment of the following:

7. Conduction disorders that require restoration of AV synchrony, including varying degrees of AV block,

8. VVI intolerance (i.e., pacemaker syndrome) in the presence of persistent sinus rhythm,

9. Low cardiac output or congestive heart failure secondary to bradycardia;

Subjects willing and capable of providing informed consent and participating in all testing and clinic visits associated with the clinical study at an approved clinical study location and at the intervals defined by protocol;

Subjects who are ≥18 years of age, and of legal age to give informed consent specific to state and national law.