Cardiovascular System - Peripheral Arterial Disease, Chronic Venous Insufficiency, Deep Vein Thrombosis, and Raynaud's Phenomenon

Peripheral Arterial Disease (PAD)

• Atherosclerotic disease develops in the extremities.
• Analogous to atherosclerosis in coronary arteries.
• Major risk factor: Smoking.
• Risk increases with age.
• Early stages can be asymptomatic.

Symptoms

• Develop as blood supply reduces due to artery narrowing.
• Intermittent claudication:
  • Lower extremity muscle pain develops with activity.
  • Relieved with rest.
• Signs of ischemia:
  • Cool, shiny skin.
  • Decreased peripheral pulses.
  • Ischemic ulcers.

Diagnosis

• Ankle Brachial Index (ABI).
• Diagnosis if ABI is less than 0.9.
• Calculation:
  • Calculated individually for each leg.
  • ABI = \frac{\text{Blood pressure in artery of the ankle}}{\text{Blood pressure in artery of the arm}}
  • Not expected to calculate for the exam, but important to know the concept.

Treatment

• Depends on severity.
• Initially address risk factors:
  • Smoking cessation.
  • Cholesterol and blood pressure control.
  • Exercise programs for intermittent claudication.
  • Long-term antiplatelet therapy.
• Severe cases: Refer to vascular specialists.

Chronic Venous Insufficiency (CVI)

• Damage to leg veins.
• Difficulty in transporting blood back to the heart.

Clinical Findings

• Lower extremity edema.
• Dilated vessels on the legs (varicose veins).
• Skin irritation.
• Hyperpigmentation.

Interventions

• Non-pharmacological interventions are usually tried first:
  • Compression therapy.
  • Leg elevation.
  • Exercises they can tolerate.
  • Adequate skin care.
• Consult vascular specialists.

Complications

• Deep Vein Thrombosis (DVT):
  • CVI causes blood to pool in lower extremities, increasing risk of blood clot.
• Ulcers or skin wounds.

Deep Vein Thrombosis (DVT)

• Blood clot in a deep vein, most commonly in the lower extremities.
• Can be provoked (identifiable cause) or unprovoked (no identifiable cause).
  • Examples of provoked causes: prolonged immobility or travel
  • Thinking about people on planes for long spans of time

Presentation

• Acute onset of localized swelling and erythema, typically in the lower extremity.

Diagnosis

• Doppler ultrasound to check for a clot.
• D-dimer blood test to support a possible diagnosis (not diagnostic by itself).
• Homan's sign: Historically used, but recent literature shows it to be unreliable.

Treatment

• First-line treatment: Direct Oral Anticoagulants (DOACs).
• Warfarin is an acceptable alternative in certain populations, such as those patients with severe kidney disease.

Raynaud Phenomenon

• Disorder characterized by episodes of narrow blood flow in the vessels of the fingers and toes causing notable color changes to the skin.
• Triggers: exposure to cold or stress.

Treatment

• Calcium channel blockers.
• Avoid triggers.