Post-Myocardial Infarction (Chronic Recovery Phase)

Populations and Risk Factors

• Age is the primary non-modifiable risk factor; the majority of MI survivors are over 55, though post-MI recovery populations are trending younger as MI incidence increases in adults aged 35–54
• Men have higher MI incidence, but women have higher post-MI mortality and are more likely to experience atypical symptoms that delay diagnosis, leading to more extensive myocardial damage before intervention
• Pre-existing coronary artery disease, hypertension, dyslipidemia, diabetes mellitus, and smoking history are the dominant modifiable risk factors — these conditions persist after the MI and require ongoing management
• Sedentary lifestyle and obesity increase both initial MI risk and the severity of post-MI deconditioning; patients who were deconditioned before the event recover more slowly
• Psychological comorbidity is extremely common: approximately 20–30% of post-MI patients develop clinical depression, and up to 40% experience significant anxiety — both independently worsen cardiac outcomes and directly produce the muscle guarding patterns the MT will assess
• Prior cardiac procedures increase the complexity of the musculoskeletal presentation — CABG (median sternotomy), percutaneous coronary intervention (PCI/stenting), and cardiac catheterization each produce distinct post-procedural tissue effects
• Type A personality traits and chronic psychosocial stress are recognized cardiac risk factors that also manifest as habitual upper trapezius, jaw, and chest wall muscle guarding

Causes and Pathophysiology

The Cardiac Event and Its Aftermath

• Myocardial infarction results from complete or near-complete occlusion of a coronary artery, most commonly from atherosclerotic plaque rupture and thrombus formation. Cardiac muscle distal to the occlusion undergoes irreversible necrosis within 20–40 minutes if blood flow is not restored. Dead myocardium is replaced by noncontractile, inelastic scar tissue over 6–8 weeks.
• The extent of myocardial damage determines the degree of cardiac functional impairment. Left ventricular ejection fraction (LVEF) — the percentage of blood ejected with each contraction — is the key prognostic measure. An LVEF below 40% indicates significant systolic dysfunction and reduced cardiac output, which directly affects exercise tolerance, fatigue levels, and hemodynamic stability during treatment.
• Reduced cardiac output means the cardiovascular system cannot adequately increase blood flow during exertion. This produces exercise intolerance, early fatigue, and dyspnea on exertion — the patient may be unable to tolerate prone positioning or lengthy sessions without becoming symptomatic.

Why Thoracic Guarding Develops

• The chest pain of the acute MI event — substernal crushing pressure — triggers a powerful protective guarding response in the muscles of the anterior and lateral chest wall. Even after the cardiac event resolves, the nervous system maintains this guarding pattern as a learned protective behavior, particularly in patients with ongoing cardiac anxiety ("fear of another heart attack").
• The intercostals, pectoralis major and minor, serratus anterior, and anterior scalenes develop sustained hypertonicity. This restricts rib cage excursion and thoracic mobility, shifting the patient toward a shallow, upper-chest-dominant breathing pattern.
• Chronic upper-chest breathing recruits the accessory breathing muscles (scalenes, sternocleidomastoid, pectoralis minor, upper trapezius) for tidal breathing — a function they are not designed to sustain. Over weeks to months, these muscles develop hypertonicity, trigger points, and fatigue-related myalgia. The SCM and scalenes become particularly problematic, producing referred pain to the head, temporal region, and anterior chest that can mimic cardiac pain and escalate the patient's anxiety.

Sternal Scar Tissue and Adhesions (Post-CABG/Sternotomy)

• CABG requires median sternotomy — the sternum is divided with an oscillating saw, the retrosternal space is accessed for bypass grafting, and the sternum is wired closed. The surgical wound heals over 8–12 weeks, but sternal scar tissue maturation continues for 12–18 months.
• The healing sternotomy produces dense fibrotic scar tissue along the sternal midline and extending into the pectoralis fascia bilaterally. Superficial adhesions bind the skin and subcutaneous tissue to the underlying pectoralis fascia, restricting fascial glide. Deep adhesions may extend to the retrosternal space, limiting anterior chest wall expansion during deep inspiration.
• Saphenous vein harvest (from the medial leg) for bypass grafts produces a secondary surgical scar with its own adhesion pattern — tenderness along the medial leg incision line, reduced fascial mobility, and potential saphenous nerve irritation.
• Sternal healing precautions are critical: the wired sternum requires 8–12 weeks to achieve adequate bony union. During this period, patients are instructed to avoid lifting, pushing, pulling with the upper extremities, and any activity that produces shearing forces across the sternum. This immobilization contributes to upper extremity and thoracic deconditioning.

Deconditioning and Postural Compensation

• Post-MI patients experience a period of enforced reduced activity — bed rest during hospitalization, activity restrictions during early recovery, and self-imposed limitation from fear of exertion triggering another event. This produces generalized cardiovascular and musculoskeletal deconditioning.
• Deconditioning manifests as reduced aerobic capacity, muscle atrophy (particularly in the lower extremities and trunk stabilizers), decreased flexibility, and postural deterioration. Patients adopt a protective kyphotic posture — rounded shoulders, forward head, reduced thoracic extension — that further restricts breathing mechanics and perpetuates the accessory muscle recruitment cycle.
• Cardiac rehabilitation (Phase I: inpatient; Phase II: outpatient supervised exercise; Phase III: independent maintenance) progressively restores cardiovascular fitness and functional capacity. The MT encounters patients primarily in Phase II (beginning 2–6 weeks post-event) and Phase III (months to years post-event). Understanding where the patient is in cardiac rehab is essential for session planning — a Phase II patient has different tolerance and risk parameters than a Phase III patient who has been exercising independently for six months.

Anxiety and Psychophysiological Muscle Guarding

• Post-MI anxiety is not merely psychological — it produces measurable physiological effects. Sympathetic nervous system hyperactivation increases resting heart rate, blood pressure, and muscle tension. The patient lives in a state of chronic low-grade fight-or-flight activation.
• This manifests as palpable muscle guarding in characteristic locations: bilateral upper trapezius (the "stress carrying" pattern), cervical paraspinals, jaw musculature (masseter, temporalis — clenching), chest wall muscles, and diaphragm. The patient may not be aware of this tension until it is pointed out.
• The anxiety-guarding cycle is self-reinforcing: chest wall muscle tension produces chest tightness → the patient interprets chest tightness as a cardiac symptom → anxiety increases → sympathetic activation increases muscle tension further. Breaking this cycle through manual therapy and patient education is a legitimate therapeutic target.

Medication Effects Relevant to Massage Therapy

• Anticoagulants (warfarin, heparin, DOACs — rivaroxaban, apixaban): reduce blood clotting ability; the patient bruises more easily and bleeds longer from minor trauma; deep aggressive techniques are contraindicated; pressure must be modified throughout the session
• Antiplatelet agents (aspirin, clopidogrel/Plavix, ticagrelor): inhibit platelet aggregation; similar bruising risk to anticoagulants; virtually all post-MI patients are on at least aspirin indefinitely and often dual antiplatelet therapy for 6–12 months post-stenting
• Beta-blockers (metoprolol, atenolol, bisoprolol): reduce heart rate and blood pressure by blocking beta-adrenergic receptors; the patient's heart rate response to exertion is blunted — normal heart rate elevation during position changes or exertion will be diminished; the MT cannot rely on heart rate as a reliable indicator of cardiovascular stress; fatigue and exercise intolerance are common side effects
• Statins (atorvastatin, rosuvastatin, simvastatin): lower cholesterol by inhibiting HMG-CoA reductase; a clinically significant side effect is statin-induced myalgia — diffuse muscle pain, tenderness, and weakness, most commonly in the proximal lower extremities (thighs, hips) and trunk; reported in 5–20% of patients; the MT must differentiate statin myalgia from other causes of diffuse muscle tenderness; in rare cases, statins can cause rhabdomyolysis (muscle breakdown) — severe muscle pain with dark urine warrants emergency medical referral
• ACE inhibitors / ARBs (ramipril, lisinopril, losartan): lower blood pressure and reduce cardiac workload; may cause orthostatic hypotension, especially when combined with beta-blockers — the patient may become dizzy when transitioning from supine to seated or standing; allow extra time for position changes and monitor for lightheadedness
• Nitrates (nitroglycerin, isosorbide mononitrate): vasodilators used for residual angina; may cause headache and hypotension; the patient may carry sublingual nitroglycerin — ask about its location at the beginning of each session in case it is needed during treatment

Signs and Symptoms

Early Recovery Phase (2–8 Weeks Post-MI)

• Fatigue and reduced exercise tolerance — the patient tires easily and may not tolerate a full 60-minute session
• Substernal or anterior chest wall discomfort — may be residual cardiac pain (angina from incomplete revascularization) or musculoskeletal in origin (sternal healing, chest wall guarding); differentiating these is critical
• Dyspnea on mild exertion — climbing onto the treatment table, position changes, or walking to the treatment room may produce shortness of breath
• Anxiety and hypervigilance about cardiac symptoms — the patient may be fearful of any chest sensation
• Sternal incision pain and tenderness if post-CABG — pulling, tightness, and clicking or grinding at the sternotomy site
• Postural guarding — shoulders protracted, trunk flexed, limited arm movement to protect the sternum
• Orthopnea (difficulty breathing when lying flat) — may require semi-reclined positioning if left ventricular function is significantly reduced

Chronic Recovery Phase (Months to Years Post-MI)

• Thoracic hypomobility — reduced rib cage excursion, restricted thoracic extension and rotation
• Accessory breathing muscle hypertonicity — scalenes, SCM, pectoralis minor, upper trapezius bilaterally; may produce secondary headaches and cervicogenic-type symptoms
• Sternal scar adhesions (post-CABG) — palpable dense fibrotic tissue along the midline incision; restricted skin and fascial glide over the sternum and pectoralis fascia; may limit deep breathing and shoulder range of motion
• Statin-induced myalgia — diffuse, bilateral proximal muscle aching, most prominent in the thighs and trunk; worse with exertion; onset typically within weeks to months of starting statin therapy
• Deconditioning effects — generalized muscle weakness, reduced flexibility, postural deterioration (increased thoracic kyphosis, forward head posture)
• Residual anxiety-driven guarding — upper trapezius and jaw tension, chest wall tightness, tendency to hold the breath during manual treatment
• Leg incision discomfort (post-saphenous vein harvest) — tenderness and numbness along the medial leg; reduced fascial mobility at the harvest site

Assessment Profile

Subjective Presentation

• Chief complaint: post-MI patients typically present reporting upper back and neck stiffness, chest tightness that is "not cardiac" (they have usually been cleared by their cardiologist), shoulder restriction (especially post-CABG), generalized muscle aches (if on statins), or difficulty taking a deep breath; many are referred by their cardiologist or cardiac rehab team specifically for stress reduction and musculoskeletal management
• Pain quality: tight, aching, pulling quality in the thoracic and cervical regions; sharp pulling at the sternal scar site with deep breathing or arm elevation (post-CABG); diffuse bilateral proximal muscle aching with statin use; burning or tingling along medial leg scar (saphenous nerve irritation post-CABG); anxiety-related tension described as "I carry all my stress in my shoulders and jaw"
• Onset: musculoskeletal symptoms develop gradually over weeks to months following the MI event; sternal scar symptoms begin after initial surgical healing (8–12 weeks) as the patient begins increasing activity; statin myalgia onset correlates with medication start date (typically within the first 6 months)
• Aggravating factors: exertion beyond current tolerance (produces dyspnea, fatigue, and potentially angina); cold environments (increase cardiac workload through peripheral vasoconstriction); emotional stress (escalates anxiety-guarding cycle); sustained postures (desk work, driving — worsen thoracic stiffness); overhead reaching and pushing/pulling (stress sternal healing site in early recovery)
• Easing factors: rest and pacing of activity; cardiac medications (beta-blockers reduce angina frequency, nitrates relieve acute angina); warm applications to tense muscles (if hemodynamically stable); relaxation and stress reduction techniques; progressive return to exercise through cardiac rehab
• Red flags: New-onset substernal crushing pressure, radiating left arm/jaw/neck pain, diaphoresis, or sudden dyspnea at rest — indicates possible re-infarction or unstable angina; emergency referral; do not treat. Severe muscle pain with dark-colored urine while on statins — possible rhabdomyolysis; urgent medical referral. New-onset syncope or near-syncope — possible arrhythmia or hemodynamic instability; medical referral before next treatment.

Observation

• Local inspection: sternal midline scar (post-CABG) — assess for keloid formation, wound healing stage, color (red/pink indicates still maturing; white/pale indicates mature scar); medial leg scar if saphenous vein harvested; no visible swelling expected in the chronic phase unless peripheral edema is present (indicating reduced cardiac output or right-sided heart failure — medical concern, not an MT target); examine fingertips for cyanosis (oxygen saturation issue) and nail beds for pallor
• Posture: increased thoracic kyphosis with protracted shoulders — the "cardiac protection posture" where the patient rounds forward to guard the anterior chest; forward head posture secondary to increased kyphosis; bilateral shoulder elevation from upper trapezius hypertonicity; reduced thoracic lordosis and limited willingness to extend; overall appearance of tension and guardedness, particularly in the upper quadrant
• Gait: generally unremarkable unless severely deconditioned; may show slow pace, reduced arm swing, and mild dyspnea on even short walking distances in early recovery; no characteristic antalgic pattern — if present, investigate an unrelated orthopedic cause

Palpation

• Tone: bilateral upper trapezius hypertonicity is nearly universal — driven by both postural compensation (kyphotic posture increases upper trapezius loading) and anxiety-mediated guarding; scalenes (anterior, middle, posterior) hypertonic bilaterally from chronic accessory breathing — the anterior scalene is typically the most involved and may reproduce anterior chest wall referral that mimics cardiac symptoms; SCM hypertonic from accessory breathing, particularly the sternal division; pectoralis minor hypertonic and shortened bilaterally — the key muscle linking protracted posture, restricted rib elevation, and breathing dysfunction; pectoralis major hypertonic, particularly the clavicular and sternal heads adjacent to the sternotomy site (post-CABG); levator scapulae and cervical paraspinals hypertonic from sustained forward head posture; masseter and temporalis if jaw clenching is present (anxiety-driven); suboccipitals hypertonic secondary to forward head position
• Tenderness: sternal midline tenderness along the surgical scar (post-CABG) — direct palpation produces sharp, localized pain at the incision site; pectoralis fascia tenderness bilateral to the sternum where adhesions bind superficial to deep layers; intercostal tenderness at rib attachments to the sternum — costochondral junction sensitivity (distinguish from costochondritis); scalene tenderness, particularly at the first rib attachment; medial leg incision tenderness (saphenous vein harvest site); if statin myalgia is present, diffuse tenderness in the proximal thigh muscles (quadriceps, hip adductors) and paraspinals bilaterally — this tenderness is symmetric, non-anatomically specific, and disproportionate to palpation pressure, distinguishing it from localized musculoskeletal pathology; trigger point tenderness in upper trapezius, levator scapulae, infraspinatus, and pectoralis minor
• Temperature: skin temperature over the chest wall should be normal in the chronic phase; warmth over the sternal scar in the first 3–4 months is normal wound healing; persistent warmth beyond 6 months may indicate infection or delayed healing — refer; coolness in the extremities is common due to beta-blocker-mediated peripheral vasoconstriction and reduced cardiac output; bilateral hand and foot coolness is a medication effect; unilateral coolness in a limb warrants medical referral (vascular concern)
• Tissue quality: sternal scar tissue — dense, fibrotic, and adherent to underlying tissues; reduced skin mobility over the scar with poor fascial glide; mature scars (over 12 months) are pale, firm, and may have thickened collagen ridges; pectoralis fascia lateral to the scar feels bound down and inelastic compared to normal tissue; thoracic paraspinal muscles feel ropy and hypertonic with reduced extensibility, reflecting chronic guarding and postural load; accessory breathing muscles (scalenes, SCM) feel taut and fibrous from sustained overuse; trigger point nodules palpable in upper trapezius, levator scapulae, pectoralis minor, and infraspinatus

Motion Assessment

• AROM: thoracic extension and rotation are the most restricted movements — the patient demonstrates limited ability to extend the thoracic spine or rotate the trunk, reflecting both muscular guarding and postural adaptation; cervical ROM may be restricted by scalene and upper trapezius hypertonicity, particularly lateral flexion and rotation; shoulder flexion and abduction may be limited by pectoralis shortening and sternal scar adhesions (post-CABG); deep inspiration is restricted — observe the patient attempting a maximal inhalation and note whether rib cage expansion is symmetric and adequate or whether the patient relies on shoulder elevation (accessory muscle recruitment) rather than lateral rib expansion
• PROM / end-feel: thoracic extension PROM typically exceeds AROM, indicating that muscle guarding rather than structural restriction is the primary limiting factor — end-feel is muscular-guarded (soft tissue stop with protective resistance) rather than capsular; shoulder PROM in post-CABG patients may reveal a firm end-feel in horizontal abduction and full flexion where pectoral scar adhesions restrict anterior chest wall stretch; cervical PROM end-feel is typically muscular in all directions, reflecting scalene and upper trapezius guarding
• Resisted testing: generally unremarkable for specific weakness patterns unless severe deconditioning is present; the patient may demonstrate generalized weakness (grip strength, shoulder abduction) from disuse; resisted testing of the shoulder girdle may reproduce sternal scar discomfort (post-CABG) with resisted horizontal adduction or push-up type movements that stress the sternotomy; pain on resisted testing without specific weakness suggests muscle guarding or statin myalgia, not structural pathology

Special Test Cluster

Vital sign monitoring protocol: Take resting BP and HR before the session begins, midway through if the session exceeds 30 minutes, and before the patient stands to leave. Compare all readings to baseline. Any significant deviation from baseline (systolic change > 20 mmHg, HR increase > 20 bpm above resting, or new irregularity) warrants stopping treatment and reassessing. If the patient is on beta-blockers, document their typical medicated resting HR at intake to establish an individual baseline — population norms do not apply.

Differential Diagnoses