Background: Atrial fibrillation (Afib) is chronic condition affecting up to 3 million people in the USA and close to 5 million people in Europe. With the U.S. population aging, the pool of individuals with Afib is expected to grow significantly reaching ~8 million by 2050. Today, eight percent of individuals above 80 years old have Afib.

Afib is not a life-threatening arrhythmia, but it can lead to the formation of clots that can travel through circulation to the brain resulting in stroke. In average 15% of strokes found their etiology into Afib rhythm and, 4% to 8% of strokes are caused by previously undiagnosed Afib 2.  Furthermore, when Afib is maintained over a long period, it leads to a weakening of the heart muscle resulting in heart failure and long-term disability. Importantly, Afib is an underdiagnosed disease as it is often asymptomatic, 30% percent of all patients with Afib are unaware of their diagnosis. When symptoms are perceived, they include: dyspnea (shortness of breath), palpitations/dizziness, and, in acute episodes they can be associated with chest discomfort. The diagnosis of Afib requires the visit to health professional(s) to perform an electrocardiogram (ECG). In challenging cases, long-term ECGs or event monitoring are critical to obtain a definitive diagnostic.

Study Design:

We enrolled AF patients who underwent direct current electrical cardioversion in the Electrophysiology Laboratory at Strong Memorial Hospital (Rochester, NY). All adult patients who underwent cardioversion for persistent AF (medically managed or not) were eligible for this study. The patients were excluded if implanted cardiodefibrillators or cardiac resynchronization therapy devices were present, if the patients refused to sign the consent form, or if the patient was unable to cooperate with the protocol. The study was approved by the local University of Rochester Medical Center (URMC) Research Subjects Review Board (Rochester, NY). While the patients were prepared for the procedure, a research nurse positioned 10 electrodes on the subject’s torso in order to record 12-lead ECG using a Mortara H12+ recorder (Mortara Instrument Inc., Milwaukee, MN) using the Mason-Likar lead configuration. The electrodes were placed adjacent to the electrodes already in place for the cardioversion procedure and around the frontal defibrillation patch.

We enrolled 26 patients into the study between August 29th, 2012 and October 28th of the following year.

Inclusion criteria: patients with a history of atrial fibrillation who are:
- men and women older than 18 years old;
- medically-managed for atrial fibrillation;
- patients with persistent atrial fibrillation;

Study Exclusion criteria:
- Patients with implantable pacemaker;
- Patients with ICD device;
- Patients with Cardiac Resynchronization Treatment (CRT) device;
- Women of childbearing potential not using medially prescribed contraceptive measures;
- Patients participating in other clinical trials;
- Patients unable to cooperate with the protocol due to dementia, psychological, or other   related reason;
- Patients who refuse to sign the consent for participation.

Number of Leads: Holter 12-lead ECGs (Mason-Likar lead configuration)

Sampling Frequency : 1000 Hz

Clinical Information: The list of clinical information available for this study are described in the following table: