The primary aim of this validation protocol is to assess cardiovascular function through transthoracic echocardiography ("Echo") measurements and the QuantaFlo HD test measuring blood flow at the finger during a forced expiration ("FE"). The study examines whether Echo-measured GLS values greater than -16% correlate with abnormal responses during FE as measured by QuantaFlo HD.

Inclusion Criteria:

• Male and female adult (≥ age 22) subjects with a minimum of 1 of the following:
• A history of Cardiovascular Diseasei or PAD
• Recorded history of at least two of the following
• Hypertension
• Diabetes
• Hyperlipidemia

Exclusion Criteria:

• Unable to safely perform a forced expiration, or unable to obtain a technically adequate FE test result
• Subjects with a pacemaker or ICD with pacemaker function
• Terminal advanced illness
• Recent cardiothoracic surgery (within 12 months)
• Retinal eye disease with anticoagulants
• History of eye surgery, within 90 days
• Uncontrolled hypertension >180 mmHg systolic pressure or >100 mmHg diastolic pressure
• Subjects with severe tremors

The study will be conducted at three clinical sites: one primary care clinic and one cardiac clinic, both with established echo referral pathways, and one dedicated echo clinic.