Rhythm Express Wearable System vs. Simultaneous Polysomnography for the Diagnosis of Obstructive Sleep Apnea in Adults With Suspected or Observed Atrial Fibrillation

The goal of this observational study is to confirm the accuracy of the sleep algorithm (software) used in the Rhythm Express Wearable System to detect sleep apnea severity. The study involves participants wearing the RX-1 mini cardiac monitor on their chest and a pulse oximeter during a traditional sleep test, known as polysomnography (PSG), conducted in a sleep center. The performance of the device will be evaluated by comparing the results from the Rhythm Express Wearable System with those from the traditional Polysomnography(PSG). Participants will: 1. Complete a Screening Visit to confirm they are eligible to participate in the study. 2. Be trained on the use of the Rhythm Express Wearable System. 3. Wear the RX-1 mini cardiac monitor on their chest for 3-5 days/nights. 4. Wear a pulse oximeter for 2 nights before a scheduled sleep study. 5. Complete a sleep study while wearing the Rhythm Express Wearable System. 6. Complete a telephone follow-up visit 5-10 days after the sleep study.

AF is a chronic, progressive, and debilitating cardiovascular disease that exacerbates other cardiovascular diseases and is a leading cause of morbidity (associated illness) and mortality (death). In addition, AF is the most common cardiac arrhythmia that leads to more hospitalizations than any other arrhythmia. Sleep disorders are also associated with a threefold increased mortality and literature suggests a doubled risk for stroke in people with OSA. Identification of OSA and treatment with CPAP is associated with a reduction in the stroke risk for OSA. Thus, early identification and treatment of AF and OSA may be of major societal benefit in reducing mortality and morbidity. The Rhythm Express Wearable System consists of the RX-1 mini Cardiac Monitor, a Nonin or Viatom Pulse Oximeter, and an Android Cell Phone with the Rhythm Express Oximetry Application. The RS-1 Sleep Algorithm is a cloud-based software as a medical device (SWMD) that receives inputs from the two FDA-cleared wearable devices. The Algorithm, together with the two wearable devices, comprises the Rhythm Express Wearable System. This multi-center, prospective, observational, confirmatory study is designed to compare sleep apnea severity classification provided by the RS-1 Sleep Algorithm with Polysomnography (PSG). The proposed research will confirm the accuracy of using the Rhythm Express Wearable System to detect apnea/hypopnea index of at least 5/15/30 in patients with observed or suspected atrial fibrillation by comparing it to data recorded in a PSG, which is considered to be the gold standard for sleep testing. In addition, the ability of the RX-1 mini to detect sleep and assess posture and respiratory rate during sleep will be evaluated. This initiative represents a significant step towards simplifying the screening process for sleep disorders in people indicated for ambulatory cardiac monitoring.