Cardiovascular and Vascular Abnormalities in M.E.

Purpose

This page explains the cardiovascular and vascular abnormalities associated with Myalgic Encephalomyelitis (M.E.), highlighting how impaired blood flow, autonomic dysfunction, and circulatory regulation contribute to symptoms and disease severity.

Key Points

1. Core Cardiovascular Features

• M.E. involves functional abnormalities, not typically structural heart disease [Cardiovasc…ormalities | PDF]
• Problems centre on:
  • Blood flow regulation
  • Autonomic nervous system dysfunction
  • Reduced oxygen and nutrient delivery to tissues

2. Orthostatic Intolerance

• A key feature of M.E. affecting many patients
• Symptoms when standing upright may include:
  • Dizziness or lightheadedness
  • Weakness
  • Palpitations
  • Breathlessness
  • Visual disturbances
  • Faintness [Cardiovasc…ormalities | PDF]
• Common overlapping conditions:
  • Postural Orthostatic Tachycardia Syndrome (POTS)
  • Neurally Mediated Hypotension (NMH)

3. Blood Volume and Circulation Issues

• Reduced circulating blood volume (hypovolemia)
• Impaired delivery of oxygen to the brain and muscles
• Poor peripheral circulation leading to:
  • Cold hands and feet
  • Mottled skin

4. Vascular Dysfunction

• Abnormal regulation of blood vessel dilation and constriction
• Endothelial dysfunction linked to inflammation and oxidative stress
• Reduced cerebral blood flow, especially when upright

5. Cardiac Function Abnormalities

• Heart structure often appears normal, but function is affected
• Observed issues may include:
  • Reduced cardiac output and stroke volume
  • Smaller heart size in some cases (“small heart” phenomenon)
  • Impaired heart filling (diastolic dysfunction)
  • Reduced ability to increase output during exertion

6. Impact on Symptoms

These abnormalities contribute to:

• Fatigue and low energy
• Cognitive dysfunction (“brain fog”)
• Dizziness and instability
• Headaches and chest discomfort
• Temperature dysregulation

7. Effects of Exertion

• Minor activity can worsen circulatory dysfunction
• After exertion:
  • Blood flow regulation declines further
  • Oxygen delivery becomes less efficient
  • Lactate production increases
• Leads to worsening symptoms and Post-Exertional Neuroimmune Exhaustion (PENE)

8. Systemic Nature of Dysfunction

• Cardiovascular issues are part of a broader multi-system dysfunction
• Involving:
  • Nervous system
  • Immune system
  • Energy metabolism
• These abnormalities reflect failure of regulation, not simple fatigue

Target Audience

This information is intended for:

• People living with M.E.
• Carers and family members
• Healthcare professionals
• Researchers and advocates

Overall Outcome

This page highlights that cardiovascular and vascular abnormalities are central features of M.E., driven by impaired circulation and autonomic dysfunction rather than structural heart disease. Understanding these issues helps:

• Explain key symptoms such as dizziness, fatigue, and brain fog
• Support accurate diagnosis and recognition
• Improve management strategies focused on stabilising circulation
• Reinforce the multi-system biological nature of M.E.

Key Summary Statement

Cardiovascular and vascular abnormalities in M.E. reflect impaired blood flow and autonomic regulation, leading to reduced oxygen delivery, exertion intolerance, and widespread symptom impact—not primary heart disease.