Chest Pain in a Patient with Recent Spinal Cord Injury

Diagnosis: Acute inferior ST-elevation myocardial infarction (STEMI), likely due to occlusion of the right coronary artery.

Effect of spinal cord injury:

• Altered sensation: Patients with complete SCI above T6 may have altered or absent chest pain perception. However, this patient reports severe chest pain, which is unusual but possible due to incomplete injury or visceral referral. The presence of pain despite SCI suggests that autonomic pathways may still be intact or that the injury is not complete. Alternatively, the pain may be due to other causes (e.g., cholecystitis), but ECG confirms STEMI.
• Autonomic dysreflexia: This patient is at risk for autonomic dysreflexia (AD) due to noxious stimuli (e.g., MI). His blood pressure is elevated (160/95), which could be AD. However, in acute MI, hypertension may be due to sympathetic activation. AD typically occurs with injuries above T6 and is characterized by paroxysmal hypertension, bradycardia, and sweating. Here, tachycardia is present, which is less typical of AD. Nonetheless, monitor for AD.
• Atypical symptoms: Patients with SCI may present with atypical symptoms such as abdominal pain, nausea, or silent MI. This patient has classic symptoms, which is helpful.
• Management considerations:
  • Thrombolysis vs. PCI: The patient is 90 minutes from PCI. Guidelines recommend primary PCI if door-to-balloon time can be achieved within 120 minutes; otherwise, fibrinolysis is recommended if symptom onset <12 hours and no contraindications. Here, PCI would take at least 90 minutes transport plus door-to-balloon time, likely >120 minutes. Therefore, thrombolysis is a reasonable option if no contraindications. However, patients with SCI may have higher risk of bleeding due to anticoagulant use? He is not on anticoagulants. But consider risk of bleeding from baclofen pump? Not mentioned. Thrombolysis is preferred if timely PCI not available.
  • Blood pressure management: His BP is elevated; in inferior MI, avoid nitrates if right ventricular involvement (leads V4R) because they can cause hypotension. Check for RV infarct. Use beta-blockers cautiously if heart rate is high and no heart failure.
  • Autonomic dysreflexia: If AD is suspected, treat with antihypertensives (e.g., nitrates, calcium channel blockers) but avoid if RV infarct. Also, treat the underlying cause (MI).
  • Positioning: Keep head of bed elevated to reduce preload if pulmonary edema, but in inferior MI, may need supine if hypotension.
  • Rehabilitation considerations: After stabilization, cardiac rehab should be adapted for SCI.

Decision: Administer thrombolytic therapy immediately, provided there are no contraindications.

Justification:

• Guideline recommendations: According to the American College of Cardiology/American Heart Association (ACC/AHA) and European Society of Cardiology (ESC) guidelines, primary PCI is the preferred reperfusion strategy for STEMI if it can be performed within 120 minutes of first medical contact (FMC). If the expected door-to-balloon time is >120 minutes, fibrinolysis should be administered within 30 minutes of arrival if there are no contraindications.
• Time analysis: The PCI center is 90 minutes away by ground ambulance. Adding transport time, door-in to door-out time, and door-to-balloon time at the PCI center, the total time from FMC to PCI will likely exceed 120 minutes. Therefore, fibrinolysis is indicated.
• Contraindications: Review contraindications: history of intracranial hemorrhage, known structural cerebral vascular lesion, ischemic stroke within 3 months, suspected aortic dissection, active bleeding, severe uncontrolled hypertension (>180/110), recent surgery, etc. The patient's BP is 160/95, which is not an absolute contraindication but should be controlled before thrombolysis. He has no reported bleeding disorders. Baclofen is not a contraindication.
• Risk of bleeding: Patients with SCI may have higher risk of bleeding due to autonomic dysfunction? Not specifically. But consider risk of bleeding from pressure ulcers or other sources.
• Alternative: If thrombolysis is contraindicated, transfer for PCI.
• Evidence: The STREAM trial and others support fibrinolysis when PCI is not available within 120 minutes. The benefit of early reperfusion outweighs the risk of bleeding.

Conclusion: Administer fibrinolytic therapy (e.g., tenecteplase) after controlling blood pressure and confirming no contraindications. Simultaneously arrange transfer to PCI center for rescue or routine early angiography.

Cardiac rehabilitation modifications:

• Exercise testing: Use arm ergometry or functional electrical stimulation (FES) cycling instead of treadmill. Monitor for autonomic dysreflexia during exercise (sudden hypertension, bradycardia, headache).
• Exercise prescription: Target heart rate may be unreliable due to altered autonomic control; use perceived exertion (RPE) and symptoms. For patients with SCI, heart rate response may be blunted; use RPE 11-13 (light to somewhat hard).
• Blood pressure monitoring: Monitor BP closely; avoid exercises that provoke AD (e.g., tight clothing, bladder distension).
• Positioning: During exercise, ensure proper seating and pressure relief to prevent skin breakdown.
• Thermoregulation: Patients with SCI have impaired thermoregulation; exercise in cool environment, monitor for overheating.
• Education: Teach signs of AD, chest pain equivalents (e.g., jaw pain, nausea, sweating), and when to seek help. Emphasize medication adherence, smoking cessation, and glycemic control.
• Psychosocial support: Address depression and anxiety, which are common post-MI and SCI.
• Interdisciplinary team: Include physiatrist, cardiologist, PT, OT, and rehab nurse.