Low Voltage-Directed Catheter Ablation for Atrial Fibrillation

Prior treatment

• History of prior left-sided catheter or surgical ablation for AF or atypical atrial flutter, including MAZE or mini MAZE.
  • Prior ablation for typical atrial flutter or left-sided ablation for WPW, AV node reentry tachycardia or focal ectopic atrial tachycardia may be included.
• Active ventricular tachycardia requiring treatment with catheter ablation or anti-arrhythmic drug within the last 6 months.
• Active enrollment in another investigational study involving a drug or device.

Other illness

• Uncontrolled heart Failure or NYHA Class IIIb or IV heart failure.
• Severe pulmonary hypertension (PAP \> 70 mmHg)
• Unstable valvular disease.
• AF secondary to electrolyte imbalance, thyroid disease or reversible non- cardiac cause.
• Inability to have implantable monitoring device for atrial fibrillation burden with no pre-existing cardiac device that can monitor atrial arrhythmias OR inability to wear external Holter Monitor continuously for 4 weeks.
• Significant congenital anomaly or medical condition that may affect the integrity of study data.
• Presence of any medical or psychological condition or medical non-compliance history that may adversely impact study outcomes.

Lab values

• Ejection Fraction \< 0.20.

Other

• Subjects will be excluded if any of the follow criteria are present:
• Left atrial size \> 60 mm diameter on echocardiogram.
• "Long standing" persistent AF defined as \> or = 1 year of continuous atrial fibrillation at the time of enrollment.
• Poor candidate for general anesthesia.
• Anticipated survival \< 1 year.
• MI or CABG within 3 months.
• Left atrial thrombus in pre-procedure imaging within 4 weeks of the ablation procedure.
• Any documented thromboembolic event within 6 months of the ablation procedure.
• Contraindication to anticoagulation.
• Women who are pregnant - pregnancy test required if pre-menopausal or non-sterile.
• Inability to undergo complete voltage mapping in normal sinus rhythm - see intraprocedural protocol.

• Subjects must meet all of the following criteria:
• Non-Paroxysmal Atrial Fibrillation.
• Failed or intolerable to at least 1 one antiarrhythmic drug (AAD).
• 18-85 year of age at time of consent.
• Scheduled to undergo a clinically indicated AF ablation procedure.
• Able and willing to comply with all protocol visit requirements.
• Signed Patient Informed Consent (ICF).
• Presence of low voltage in the left atrium on 3-D map during index catheter ablation procedure