Effect of Midodrine vs Abdominal Compression on Cardiovascular Risk Markers in Autonomic Failure Patients

Inclusion Criteria: * Male and female subjects, age 40-80 years, with autonomic failure including pure autonomic failure, multiple system atrophy and Parkinson disease. * Neurogenic orthostatic hypotension, defined as a ≥20-mmHg decrease in SBP within 3 minutes of standing associated with impaired autonomic reflexes determined by autonomic testing in the absence of other identifiable causes. * Patients who are willing and able to provide informed consent Exclusion Criteria: * Pregnancy. * Patients with any contraindication or intolerant to abdominal compression including history of aortic aneurysms, thoracic, abdominal or pelvic surgery within 6 months of study participation; symptomatic abdominal or inguinal hernias; severe gastrointestinal reflux; recent fractures or fissures of ribs, thoracic or lumbar spine; medical devices implanted on the abdominal wall or abdomen that would interfere with the abdominal compression. * Pre-existing sustained supine hypertension ≥180/110mmHg * Bedridden patients or those who are unable to stand due to motor impairment or severe OH. * Patients who cannot tolerate the medication withdrawal, defined as those who are unable to stand for at least one minute after the medication withdrawal period or those with sustained supine hypertension ≥180/110mmHg. * Clinically unstable coronary artery disease, or major cardiovascular or neurological event in the past 6 months. * Clinically significant pulmonary, renal, hematopoietic, hepatic disease, o…