To characterize the impact of orthostatic hypotension (OH) and Vasovagal syncope on signals measured using a wearable Holter monitor in the clinic and ambulatory setting.

To evaluate the relationship of signals measured from the Holter monitor with reported symptom severity of orthostatic intolerance per standard data collection, analysis, and questionnaires.

This is a non-randomized feasibility study that will enroll up to 40 participants that have undergone a previous autonomic reflex screen (ARS) assessment and were either diagnosed with OH or reflex syncope or considered to be control subjects for this study.

A minimum of 20 subjects diagnosed with reflex syncope; a maximum of 15 subjects diagnosed with OH syncope and a maximum of 15 control subjects will be enrolled. There will be one in person study visit and a 21 day follow up period per subject.

Inclusion Criteria:

• Willing and capable to provide informed consent
• Age 18 or above
• Previously underwent a clinically indicated ARS assessment without complications (including deep breathing, Valsalva maneuver, and tilt table testing).
• Previously diagnosed with OH, Vasovagal syncope, OR control subjects assessed as normal, based on the ARS assessment. Participant enrollment shall be based on the type of diagnosis.
• Willing to complete all required study activities.

Exclusion Criteria:

• Currently enrolled in another clinical trial that might interfere with data collection.
• Subject is pregnant or planning to become pregnant during the study
• Active Implantable Medical Device, e.g. cardiac implantable electronic devices, bladder stimulators, diaphragm stimulators, implantable neuro stimulator, implantable active monitoring devices, implantable active drug administration devices, etc.
• Have a prosthetic cardiac valve or previously underwent cardiac valve surgery.
• Known allergy to materials used in the study (adhesive, ECG electrodes)
• Diagnosed with syncope due to cardiologic causes.
• Have had a myocardial infarction in the previous 90 days
• Have been diagnosed with tachycardia that requires current medical treatment
• Have any contraindications for exercise testing, tilt table test, Valsalva maneuver test or deep breathing test (judged by the study Principal Investigator)

Patients that have previously undergone an ARS assessment and were diagnosed with OH or reflex syncope, or are control subjects

IPD will not be shared due to privacy and confidentiality barriers in a small study population.