Prediction and Maintenance of Sinus Rhythm Among Atrial Fibrillation Patients
Prediction and Maintenance of Sinus Rhythm Among Atrial Fibrillation Patients
Atrial fibrillation (AF) is the most common heart rhythm disorder seen in clinical practice,
 with an estimated 2.7-6.1 million people in the U.S. affected by the disorder [1]. Previous
 studies have demonstrated that left atrial volume is a predictive measure of incident atrial
 fibrillation [2]. This study aims to add to the literature by investigating predictive
 measures of left atrial global longitudinal strain (LA GLS) that would be suggestive of
 maintenance of normal sinus rhythm post cardioversion. If the investigators could gain
 insight on the connection between LA GLS and cardioversion among patients with atrial
 fibrillation, the investigators could potentially help the clinical management of patients
 pre/post cardioversion, and potentially change poor outcomes.
Atrial fibrillation (AF) is a heart rhythm disorder in which the normal beating in the upper
 chambers of the heart is irregular, leading to poor blood flow to the lower chambers. Risk
 factors include older age, high blood pressure, obesity, European ancestry, diabetes, heart
 failure, ischemic heart disease, hyperthyroidism, chronic kidney disease, heavy alcohol use,
 and enlarged heart chambers on the left side [3]. AF increases a person's risk for stroke and
 contributes to an estimated 130,000 deaths each year [1]. Treatment generally includes
 medication, surgery, and/or healthy lifestyle changes [1]. Electrical cardioversion, in which
 the patient must undergo sedation or general anesthesia, is also used to convert patients
 with persistent AF to normal sinus rhythm. Electrical cardioversion has been associated with
 a high initial success rate of 68-98% [4], but long-term maintenance of sinus rhythm has
 proved challenging [5]. Due to the potential risks incurred to the patient, it is important
 to understand which patients are good candidates for cardioversion therapy. A review article
 describes that duration of AF, sex, age, weight smoking status, number of shocks at
 cardioversion, post-ablation procedure, medications, hypertension, diabetes, Chronic
 Obstructive Pulmonary Disease (COPD), obstructive sleep apnea, renal impairment,
 hyperthyroidism, coronary artery disease, congestive heart failure, left systolic
 dysfunction, left diastolic dysfunction, left ventricular hypertrophy, valvular heart
 disease, and left atrial size have each been found to be associated with maintenance of sinus
 rhythm [6].

 Echocardiography has been increasing used in understanding the cardiac structure and risk of
 stroke among patients with AF, with left atrial size, left ventricular wall thickness, and
 left ventricular dysfunction recognized as independent predictors of AF [7]. Increasing
 evidence supports that the left atrial strain measurements can be a predictor of outcomes
 among AF patients, including stroke and AF recurrence after catheter ablation [8], [9]. The
 investigators aim to further explore left atrial strain measurements, including left atrial
 global longitudinal strain (LA GLS), as predictors of maintenance of normal sinus rhythm
 post- cardioversion. It is anticipated that a lower LA GLS will predict AF recurrence. To do
 this, the investigators will study patients with AF at Pen Bay Medical Center who have
 undergone cardioversion, measuring their LA GLS pre-cardioversion, and assess maintenance of
 sinus rhythm 6 months post-cardioversion. It is anticipated that this study will confirm LA
 GLS as a marker for maintenance of sinus rhythm post-cardioversion.
Inclusion Criteria:

 -  • Patients identified at PBMC with a documented diagnosis of AF (at any point in time)
 and who have undergone any cardioversion.

 -  The patient would also need to have had an echocardiogram within six months
 pre-cardioversion (performed for any reason) with a well visualized atrial roof
 in order to perform the measurements accurately using the TOMTEC-ARENA software.

 Exclusion Criteria:

 -  • Patients with a mitral regurgitation greater than moderate (effective regurgitant
 orifice >= .2 mm2)

 -  Patients with post-surgical valve repair or replacement, if the procedure was
 done with a thoracotomy

 -  Any patient how has had any cardiac surgery requiring a thoracotomy