Populations and Risk Factors
- History of smoking, hypertension, high cholesterol, diabetes
- Coronary artery disease, prior angina pectoris
- Family history of heart disease (first-degree relative with MI before age 55/65)
- Plaque disruption most frequent in the first hour after awakening (catecholamine surge)
- Males > females until menopause. Post-menopausal risk equalizes
- Metabolic syndrome, obesity, sedentary lifestyle
Causes and Pathophysiology
- Atherosclerotic plaque rupture exposes subendothelial collagen, attracting platelets and forming a thrombus that completely occludes the coronary artery
- Ischemic cascade: Cardiac cells deprived of oxygen switch to anaerobic metabolism, develop acidosis, lose contractile function, and die. Irreversible necrosis begins within 20-40 minutes
- Scar formation: Dead cardiac myocytes are replaced by noncontractile, inelastic scar tissue — this permanently reduces cardiac output proportional to the area of damage
- Ventricular fibrillation is the most common cause of sudden cardiac death in the first hours post-MI
- Complications: Ventricular aneurysm from weakened wall, papillary muscle rupture, pericarditis (Dressler syndrome), heart failure
Signs and Symptoms
- Crushing substernal chest pain radiating to the left arm, neck, jaw, or back
- Pain NOT relieved by rest or nitroglycerin (differentiates from angina)
- Dyspnea, profuse sweating (diaphoresis), cold/moist skin
- Nausea, vomiting, "feeling of impending doom"
- Silent MI: No symptoms in 22-64% of cases (common in females, elderly, diabetics) — extremely dangerous because treatment is delayed
- Red flags: Sudden chest pressure, radiating arm pain, or fainting = call 911 immediately; the "golden hour" for reperfusion is 60-90 minutes
CMTO Exam Relevance
- Category A7 Systemic Conditions — Cardiovascular
- Must differentiate MI (crushing, radiating, not relieved by rest/NTG) from angina (relieved by rest/NTG) and pericarditis (positional, pleuritic)
- Silent MI is common in women, elderly, and diabetics — no pain does not mean no MI
- The "golden hour" for reperfusion therapy (60-90 minutes) is critical exam knowledge
- Cardiac troponin and CK-MB are the gold standard serum biomarkers. ST-segment elevation (STEMI) on ECG
Massage Therapy Considerations
- Recent/acute MI: Absolute contraindication for rigorous massage
- Post-recovery (physician clearance): Gentle Swedish relaxation once the client has returned to normal physical activity levels (typically 6-12 weeks post-MI depending on severity)
- Anticoagulant/antiplatelet drugs: Most post-MI clients are on blood thinners (aspirin, clopidogrel, warfarin) — deep pressure and aggressive techniques are contraindicated due to increased bruising risk
- Positioning: Side-lying or semi-supine. Avoid prone if chest or sternal incision from CABG. Allow extra time for position changes
- Avoid: Anterior chest and neck massage post-CABG surgery. Muscle stripping and cross-fiber friction
- Hydrotherapy: Mild warmth only. Avoid hot immersion or extreme temperature contrasts (blood pressure instability)
Key Takeaways
- Recent or acute MI contraindicates rigorous massage. Anticoagulant/antiplatelet drugs increase bruising risk, contraindicating deep techniques
- Sudden chest pressure, radiating arm pain, or fainting requires calling 911 immediately — the "golden hour" is 60-90 minutes
- MI pain is NOT relieved by rest or nitroglycerin, distinguishing it from angina
- Silent MI (no symptoms) occurs in 22-64% of cases — most common in women, elderly, and diabetics
- Post-recovery: gentle Swedish relaxation once the client returns to normal activity levels. See post-myocardial-infarction for detailed MT protocols