Risk Factors That Contribute to the Maintenance of Sinus Rhythm
Risk Factors That Contribute to the Maintenance of Sinus Rhythm
This is a prospective clinical research study. The objective of this study is to evaluate if
 clinical risk factors as well as structural features on echocardiography affect the
 maintenance of sinus rhythm after electrical cardioversion at 30 days. The investigators
 anticipate 140 patients to be enrolled in the study.
Atrial fibrillation is the most commonly diagnosed arrhythmia in the United States. A
 systematic review of worldwide population-based studies estimated that approximately 33
 million people were diagnosed with atrial fibrillation in 2010. The prevalence of atrial
 fibrillation in the United States increases with advancing age. Approximately 1% of patients
 with atrial fibrillation are under 60 years of age whereas more than one-third are over 80
 years of age.

 Although atrial fibrillation is commonly diagnosed and continues to have increased incidence
 in the country, patients continue to be admitted to the hospital for worsening symptoms of
 chest pain, shortness of breath, and palpitations. Long-term complications of atrial
 fibrillation include cardiomyopathy, cerebrovascular events, thromboembolic events, and
 death.

 Many medications have been established to convert patients from atrial fibrillation to normal
 sinus rhythm; however procedures of cardioversion and ablation have also proven to be
 effective. A study, the AFFIRM trial, published in the New England Journal of Medicine in
 2002 discussed the benefit of converting patients to sinus rhythm versus keeping patients in
 atrial fibrillation, however making sure their heart rates were well-controlled. This study
 did not demonstrate a significant difference in death, ischemic stroke, or major bleeding in
 both treatment arms suggesting there is no benefit of converting patients from atrial
 fibrillation to normal sinus rhythm. However, with increasing health costs occurring around
 the country, every effort should be made to help improve patient symptoms and avoid
 unnecessary hospitalizations. A study published in the Journal of American College of
 Cardiology in 2004, "Effect of rate or rhythm control on quality of life in persistent atrial
 fibrillation: Results from the Rate Control Versus Electrical Cardioversion (RACE) study,"
 concluded that the quality of life was impaired in patients with atrial fibrillation. Another
 study published in 2012, "Economic Burden of Atrial Fibrillation: Implications for
 Intervention," reported total costs of atrial fibrillation care in the United States to be
 estimated to be $6.65 billion per year.

 Our study is designed to look at patients with atrial fibrillation who underwent electrical
 cardioversion to restore sinus rhythm and create a prediction model to identify specific risk
 factors, which may contribute to persistent atrial fibrillation.

 Prediction models have been established in regards to maintaining sinus rhythm, including the
 Hatch Score, which examined risk factors of hypertension, history of TIA or stroke, chronic
 obstructive pulmonary disease, and heart failure that predisposed patients to persistent
 atrial fibrillation. Another score established was the LADS score, which observed risk
 factors of left atrial diameter, age, history of stroke, and smoking status as predictors of
 persistent atrial fibrillation. The purpose of our study is to create a new prediction model
 using clinical and echocardiographic parameters to determine if these factors will predict
 persistent atrial fibrillation after electrical cardioversion. Transesophageal
 echocardiographic parameters include imaging of the left atrial appendage (LAA) and
 calculating the LAA ejection fraction (LAAEF) by 3D or biplane Simpson method (based on image
 quality), and using pulse-wave Doppler to calculate the LAA exit velocity and S/D ratio
 across the pulmonic vein. Transthoracic echocardiographic parameters include estimated
 pulmonary arterial pressure (PASP) using tricuspid regurgitation (TR) jet velocity, left
 atrial volume index (LAVi), left ventricular (LV) size, LV hypertrophy (LVH) and left
 ventricular ejection fraction (LVEF).
Inclusion Criteria:

 -  Age >18 years

 -  Documented atrial fibrillation by electrocardiogram (ECG)

 -  Patients undergoing electrical cardioversion for atrial fibrillation

 -  Patients with a baseline transthoracic echocardiography within 1 month prior to the
 cardioversion

 Exclusion Criteria:

 -  Patients who did not convert to normal sinus rhythm after electrical cardioversion

 -  Patients who are found to have a LAA thrombus on TEE

 -  Patients who do not have a follow up ECG