The LEADLESS Observational Study

Inclusion Criteria

• Subject must have one of the following clinical indications: Chronic atrial fibrillation with 2 or 3° AV or bifascicular bundle branch block (BBB block) ; or Normal sinus rhythm with 2º or 3° AV or BBB block and a low level of physical activity or short expected lifespan (but at least one year); or Sinus bradycardia with infrequent pauses or unexplained syncope with EP findings; and
• Subject ≥18 years of age; and
• Subject has life expectancy of at least one year and is a suitable candidate based on overall health and well-being; and
• Subject is not enrolled in another clinical investigation with a treatment arm or that could confound the results of this study; and
• Subject is willing to comply with clinical investigation procedures and agrees to return for all required follow-up visits, tests, and exams; and
• Subject has been informed of the nature of the study, agrees to its provisions and has provided written informed consent, approved by the EC; and
• Subject is not pregnant and does not plan on getting pregnant during the course of the study.

Exclusion Criteria

• Known pacemaker syndrome, have retrograde VA conduction or suffer a drop in arterial blood pressure with the onset of ventricular pacing; or
• Hypersensitivity to < 1 mg of dexamethasone sodium phosphate; or
• Mechanical tricuspid valve prosthesis; or
• Pre-existing pulmonary arterial (PA) hypertension (PA systolic pressure exceeds 40mmHg or RV systolic pressure (RVSP) as estimated by echo exceeds 40mmHg) or significant physiologically-impairing lung disease (has severe pulmonary disease producing frequent hospitalization for respiratory distress or requiring continuous home oxygen); or
• Pre-existing ventricular pacing or defibrillation leads; or
• Current implantation of either conventional or subcutaneous implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT); or
• Presence of implanted vena cava filter; or
• Evidence of thrombosis in one of the veins used for access during the procedure; or
• Cardiovascular or peripheral vascular surgery/intervention within 30 days of enrolment; or
• Presence of implanted leadless cardiac pacemaker