Prospective, non-interventional, multi-center, international registry in two phases in consecutive patients undergoing elective cardiac surgery.

The DefiPace registry is designed in two phases

1. to document the standard of care in 50 patients with atrial fibrillation (AF)
2. to assess the treatment and outcomes of patients with post-operative atrial fibrilllation using low-energy cardioversion and subsequent bi-atrial pacing in clinical practice in 100 patients

Phase A Approximately 150 consecutive patients undergoing elective cardiac surgery (bypass and / or valve surgery)

• Data regarding standard of care post-operative pacing and treatment of POAF, if applicable, will be collected from time of surgery until discharge
• No use of an external bi-atrial pacing device
• No use of Defipace
• In-hospital data will be collected for all patients
• Patients that developed POAF (n=50) will be followed-up with a phone call 30 days after surgery.

Phase B Approximately 300 consecutive patients undergoing elective cardiac surgery (bypass and / or valve surgery) with planned TMA implantation

• In-hospital data will be collected for all patients
• Use of the DefiPace system for the treatment (low-energy cardioversion) and post-operative prevention (bi-atrial pacing) of POAF will be documented (n=100). These patients will be followed-up with a phone call 30 days after surgery

Inclusion Criteria:

• Patient is scheduled to undergo elective open chest cardiac surgery (bypass and / or valve surgery)
• Patient is at least 18 years old
• Patient with isolated bypass surgery is at least 70 years old
• Patient with valve surgery is at least 60 years old
• Patient provides written informed consent prior to the procedure
• Phase B only: patient is scheduled for TMA implantation during the elective cardiac surgery and is potentially eligible for DefiPace use

Exclusion Criteria:

• Clinical history of either permanent, persistend or paroxysmal atrial fibrillation
• Permanent pacemaker/defibrillator, other intra-cardiac active implanted electronic devices
• Minimally-invasive surgery
• Recent stroke within the last 3 months
• A history of or current endocarditis
• Pregnacy at the time of surgery

Phase A Approximately 150 consecutive patients undergoing elective cardiac surgery (bypass and / or valve surgery) Phase B Approximately 300 consecutive patients undergoing elective cardiac surgery (bypass and / or valve surgery) with planned TMA implantation.