Pathophysiology
- Initiation — endothelial injury: The process begins with damage to the arterial endothelium from hypertension (mechanical shear stress), smoking (chemical toxins), hyperglycemia, hyperhomocysteinemia, or chronic inflammation. The damaged endothelium becomes permeable to circulating lipids and loses its normal antithrombotic properties.
- Fatty streak formation: Low-density lipoprotein (LDL) cholesterol infiltrates the damaged intima and becomes oxidized. Oxidized LDL is highly inflammatory — it recruits monocytes from the bloodstream, which differentiate into macrophages. Macrophages engulf oxidized LDL, becoming lipid-laden foam cells. Accumulations of foam cells form fatty streaks — the earliest visible lesion. Fatty streaks can be found in the aortas of teenagers, demonstrating how early the process begins.
- Plaque progression: Smooth muscle cells migrate from the tunica media into the intima and proliferate, producing collagen and forming a fibrous cap over the growing lipid core. The mature plaque consists of a soft, necrotic lipid core covered by a fibrous cap. As the plaque grows, it encroaches on the vessel lumen, progressively restricting blood flow.
- Stable plaque: Thick fibrous cap, small lipid core, gradual lumen narrowing. Produces symptoms of chronic ischemia under exertion (stable angina, intermittent claudication) when stenosis exceeds approximately 70%.
- Unstable (vulnerable) plaque: Thin fibrous cap, large lipid core, heavy inflammatory infiltrate. The thin cap can rupture, exposing the thrombogenic lipid core to circulating blood and triggering acute thrombus formation. This is the mechanism behind most myocardial infarctions and ischemic strokes — sudden occlusion of a vessel that may have been only moderately narrowed.
- Systemic disease: Atherosclerosis is never a single-vessel problem. If present in the coronary arteries, it is likely also present in the cerebral, renal, and peripheral arterial beds. This systemic nature explains why a client with known CAD is also at risk for stroke, renovascular hypertension, and peripheral artery disease.
Signs and Symptoms
- Often asymptomatic until significant stenosis (> 70%) or acute plaque rupture occurs — the "silent" phase may last decades
- Coronary arteries: Angina (exertional chest pain), dyspnea on exertion. Acute plaque rupture causes MI
- Cerebral arteries: Transient ischemic attacks (TIAs — brief neurological deficits that resolve within 24 hours), cognitive decline. Acute occlusion causes ischemic stroke
- Peripheral arteries: Intermittent claudication (calf or thigh pain with walking that relieves with rest), diminished or absent distal pulses, hair loss and shiny thin skin on lower extremities, delayed wound healing, pallor on leg elevation
- Renal arteries: Renovascular hypertension (secondary hypertension resistant to standard medications)
- Xanthomas (yellowish lipid deposits under the skin, especially around eyelids and tendons) in severe hyperlipidemia
Red Flags
- Sudden chest pain, diaphoresis, and dyspnea — possible acute coronary syndrome from plaque rupture. Call 911
- Sudden neurological deficit (facial droop, speech difficulty, unilateral weakness) — possible stroke. Call 911
- Sudden severe limb pain with pallor, pulselessness, and coolness — acute arterial occlusion. Call 911 (see acute-arterial-occlusion)
- Pulsatile abdominal mass on palpation during abdominal work — possible abdominal aortic aneurysm (AAA). Stop abdominal work, refer urgently
Massage Therapy Considerations
- Relaxation massage is indicated: Reducing sympathetic tone lowers blood pressure, heart rate, and stress hormones (cortisol, catecholamines) that contribute to endothelial damage. Massage supports the client's cardiovascular risk reduction strategy alongside medical management.
- Deep abdominal work contraindicated when AAA is known or suspected: Atherosclerosis weakens arterial walls and can produce aortic aneurysms. If a pulsatile, expansile mass is felt during abdominal or psoas work, stop immediately and refer.
- Do not massage directly over known stent or graft sites without physician clearance.
- Blood pressure monitoring: Check BP before and after sessions for clients with known cardiovascular risk. Avoid vigorous techniques that significantly raise heart rate or blood pressure.
- Position transitions: Clients on antihypertensives (ACE inhibitors, ARBs, beta-blockers, calcium channel blockers) are at risk for orthostatic hypotension. Allow slow, supported transitions between positions.
- Peripheral arterial insufficiency: In extremities with diminished pulses, hair loss, and shiny skin (signs of PAD), reduce pressure — these tissues have poor perfusion, reduced resilience, and impaired healing capacity.
- Statin-related myalgias: Statins (atorvastatin, rosuvastatin) are ubiquitous in atherosclerosis management. Up to 10% of clients on statins report myalgias — diffuse muscle soreness and weakness, typically affecting proximal muscles (thighs, shoulders). This is a medication side effect, not a musculoskeletal condition. Adjust pressure if the client reports unexplained muscle soreness. Rarely, statins cause rhabdomyolysis (severe muscle breakdown) — sudden severe muscle pain with dark urine is a medical emergency.
- Antiplatelet and anticoagulant awareness: Clients are commonly on aspirin, clopidogrel, or DOACs. These increase bruising risk. Avoid deep friction, cupping, and aggressive techniques.
CMTO Exam Relevance
- Category A7 — Systemic Conditions (Cardiovascular)
- Atherosclerosis is the foundational pathology for angina, MI, stroke, and PAD — understanding the plaque progression and rupture mechanism is essential for connecting these conditions
- Stable plaque versus unstable (vulnerable) plaque — the key concept explaining why some patients have chronic stable symptoms while others have sudden acute events
- Statin-related myalgias are a commonly tested medication effect that must be differentiated from true musculoskeletal pathology
- Peripheral artery disease signs (diminished pulses, intermittent claudication, hair loss, skin changes) may be detected during MT assessment — these findings warrant medical referral and pressure modification
Key Takeaways
- Atherosclerosis is the underlying cause of most heart attacks, strokes, and peripheral artery disease — it develops silently over decades and is always systemic
- Stable plaques narrow the lumen gradually and cause exertional symptoms. Unstable plaques rupture suddenly and cause acute events (MI, stroke) even in vessels with moderate narrowing
- Deep abdominal work is contraindicated when AAA is known or suspected. A pulsatile abdominal mass is a critical red flag
- Statin-related myalgias affect up to 10% of clients on statins and must be differentiated from musculoskeletal conditions
- Clients on antiplatelet agents and anticoagulants bruise easily — reduce pressure and avoid aggressive techniques
- Relaxation massage is therapeutically beneficial — parasympathetic activation directly counteracts the sympathetic dominance that contributes to endothelial damage and disease progression
- Diminished distal pulses, hair loss, and shiny skin on extremities indicate PAD and require pressure reduction in those areas