The purpose of this study is to conduct an observational investigation of a novel care path used to manage emergency department (ED) presenting syncope patients on an outpatient basis.

OBJECTIVES To conduct a prospective observational study assessing a unique outpatient care model in which syncope patients are provided with, and trained to use, a wearable defibrillator prior to discharge from the emergency department (ED). Observational data will be collected to assess the logistics of equipping patients with the device and providing training in the ED, and the ability of patients to receive follow-up care on an outpatient basis. In addition, data will be collected to confirm that the device meets expected safety. The experience gained from this stage of the study will be used to guide future studies of device's functionality enhancements and definitive device safety and efficacy.

STUDY POPULATION Participants will be patients presenting to the ED following a syncope event which has been defined as cardiac, or potentially cardiac, i.e. undiagnosed in nature.

INTERVENTION A wearable defibrillator optimized for short-term ambulatory use with adhesive electrodes will be prescribed for up to 14 days of use following emergency department discharge or until the physician responsible for the subject's care defines an alternative treatment plan.

STUDY DESIGN This is a single-arm feasibility study.

STUDY SIZE The study will enroll a minimum of 50 and a maximum of 80 subjects. A maximum of 20 centers will be used for enrollment.

Inclusion Criteria:

1. Age≥18
2. Experienced a syncopal event within the past 48 hours
3. Either one of the following profiles(A or B) apply:

A. ED workup indicates that the patient may have experienced syncope that is cardiac in nature (any one or more of the following apply:

• History or diagnosis of structural heart disease

• History of cardiovascular disease

• Age ≥ 40

• Palpitations experienced pre-syncope

• Major ECG abnormalities:

  • QRS-duration greater than 140 ms
  • PR-interval greater than 200 ms
  • Non-specific repolarization abnormality

• Syncope experienced without any warning

• Syncope experienced while supine

• Syncope during exercise B. ED workup does not indicate a clear cause of the syncopal event

Exclusion Criteria:

1. Clear diagnosis of non-cardiac syncope (e.g. orthostatic hypotensive syncope, vasovagal syncope, carotid sinus syncope, situational fainting)

2. An active implantable cardioverter-defibrillator (ICD)

3. An active unipolar pacemaker

4. Significant risk or suffering a cardiovascular event such as:

   • Symptoms of New York Heart Association (NYHA) class III or IV heart failure
   • ED diagnosis of acute coronary syndrome
   • Having required resuscitation in response to the index syncopal event
   • Advanced directive prohibiting resuscitation (DNR)

6. Physical or mental conditions preventing subjects from interacting with or wearing the device as determined by the investigating physician.

7. Bandages or other clinical condition preventing SWD 1000 use 8. Injuries or other conditions beyond simple syncope that require hospitalization 9. Travel out of town during the study participation period that prevents the field service representative from visiting the subject daily 10. Unable or unwilling to provide written informed consent

30 days