This study was designed to screen high risk patients in nursing homes for atrial fibrillation with intermittent electrocardiogram (ECG) recordings using a portable, smartphone-based, mobile ECG recording device (Kardia Mobile, AliveCor, Inc.). The investigators hypothesized that screening patients with 2 or more risk factors for atrial fibrillation would yield a higher incidence of atrial fibrillation compared to prior studies.

This is a prospective study that enrolled 245 residents from 15 participating nursing homes with ≥2 risk factors for atrial fibrillation. All residents gave informed consent or had a legally appointed representative who could consent on their behalf. Exclusion criteria included residents with a prior diagnosis of atrial fibrillation, continuous rhythm monitoring over the past year, and pacemaker or implantable cardioverter defibrillator in situ.

Screening was performed using the smartphone-based, mobile ECG recording device. Thirty second rhythm recordings were obtained on each resident on four different occasions within a month. All tracings were reviewed by a cardiologist and, in the case of any uncertainty, the diagnosis of atrial fibrillation was confirmed by an electrophysiologist. When atrial fibrillation was detected in a resident (primary endpoint), no further rhythm recordings were performed and the resident's nursing facility was then notified of the diagnosis. Further evaluation and treatment were directed by the resident's primary care physician.

All data were stored on a secure encrypted server with password protection. The investigators used chi-square and t-test analyses to determine if there were significant differences in demographic variables or risk factors for atrial fibrillation between residents with and without atrial fibrillation. Logistic regression analysis determined if any combination of risk factors was predictive of a positive atrial fibrillation screen.

Inclusion Criteria:

Nursing home residents with ≥2 of the following risk factors for atrial fibrillation:

• age ≥75 years
• female sex
• obstructive sleep apnea
• peripheral vascular disease
• diabetes mellitus
• obesity (body mass index [BMI] >30 kg/m2)
• hypertension
• congestive heart failure

Exclusion Criteria:

• prior diagnosis of AF
• continuous rhythm monitoring over the past year
• pacemaker or implantable cardioverter defibrillator in situ

nursing home residents