In this prospective, randomized, controlled, unblinded, mono-center study, we aim to evaluate the efficacy of vein of Marshall ethanol infusion during left atrial linear ablation in patients with atrial fibrillation compared to the ALINE protocol.

Inclusion Criteria:

• Patients between the ages of 18 and 85 years
• Diagnosed with symptomatic AF without previous mitral isthmus line ablation

Exclusion Criteria:

• Previous MI line ablation
• Left atrial thrombus. LAA thrombus can be determined by preprocedural imaging: CT, TEE or MRI.
• LA diameter greater than 55 mm on long axis parasternal view, or left atrial volume more than 200 cc.
• Left ventricular ejection fraction <35%.
• Cardiac surgery within the previous 90 days.
• Expecting cardiac transplantation or other cardiac surgery within 180 days.
• Coronary PTCA/stenting within the previous 90 days or myocardial infarction within the previous 60 days.
• Documented history of a thromboembolic event within the previous 90 days.
• Diagnosed atrial myxoma.
• Significant restrictive, constrictive, or chronic obstructive pulmonary disease with chronic symptoms.
• Significant congenital anomaly or medical problem that in the opinion of the investigator would preclude enrollment
• Women who are pregnant or who plan to become pregnant during the study.
• Acute illness or active infection at time of index procedure
• Renal insufficiency
• Unstable angina.
• History of blood clotting or bleeding abnormalities.
• Contraindication to anticoagulation.
• Life expectancy less than 1 year.
• Uncontrolled heart failure.
• Presence of a condition that precludes vascular access.
• INR greater than 3.5 within 24 hours of procedure - for patients taking warfarin.
• Patient cannot be removed from antiarrhythmic drugs for reasons other than AF.
• Unwilling or unable to provide informed consent.