284.3 🏥 內科專科考前版

284.3.1 Mechanistic Deep Dive

284.3.1.1 IL-1 Pathway in Recurrent Pericarditis

  • IL-1α and IL-1β key inflammatory drivers
  • NLRP3 inflammasome activation
  • Autoinflammatory mechanism in idiopathic recurrent pericarditis
  • Rilonacept: IL-1α + IL-1β trap
  • Anakinra: IL-1 receptor antagonist
  • Effective for ~ 96% reduction in recurrence (RHAPSODY)

284.3.1.2 Constrictive Hemodynamics

  • Fixed end-diastolic volume regardless of filling pressure
  • Rapid early filling (initial filling unimpeded) then abrupt cessation
  • “Dip and plateau” / “square root sign”
  • Ventricular interdependence (filling of one ventricle compresses other)
  • Respiratory variation due to fixed pericardial volume

284.3.2 Recent Trials & Updates

284.3.2.1 RHAPSODY (2020)

  • N = 86 recurrent pericarditis
  • Rilonacept SC weekly vs placebo
  • 96% reduction in recurrence at 24 weeks
  • FDA approved 2021
  • Allows steroid tapering

284.3.2.2 AIRTRIP (2016)

  • Anakinra in colchicine + steroid refractory pericarditis
  • ↓ recurrence
  • Daily SC injection

284.3.2.3 COVID-19 Pericarditis

  • SARS-CoV-2 myopericarditis
  • mRNA vaccine-associated (young males, rare, mostly self-limited)
  • Treatment: NSAID + colchicine; rest

284.3.3 High-Yield Specialist Points

284.3.3.1 Myopericarditis vs Perimyocarditis

  • Both have pericardial + myocardial involvement
  • Myocarditis-predominant: troponin highly elevated, LV dysfunction → CMR
  • Pericarditis-predominant: troponin mild, normal LV
  • Treatment: based on severity of myocardial involvement (Ch270)
  • Exercise restriction critical

284.3.3.2 Purulent Pericarditis

  • Rare but life-threatening
  • Bacterial: Staph aureus, Strep pneumonia, anaerobes
  • Risk: bacteremia, post-thoracic surgery, immunocompromised
  • Treatment: IV antibiotics + surgical drainage + pericardiocentesis
  • Mortality high

284.3.3.3 Tubercular Pericarditis

  • Common globally
  • Sub-acute / chronic
  • Effusive → effusive-constrictive → constrictive
  • High ADA in pericardial fluid (> 40)
  • Treatment: 4-drug TB regimen + steroids (debated)
  • Pericardiectomy if constrictive

284.3.3.4 Malignant Pericardial Effusion

  • Common in lung, breast, lymphoma, melanoma
  • Often hemorrhagic
  • Cytology + flow cytometry
  • Treatment: pericardiocentesis + pericardial window + treat malignancy
  • Recurrent: sclerosing agents (bleomycin), tunneled catheter

284.3.3.5 Uremic Pericarditis

  • BUN > 60 traditional cutoff (now less strict)
  • Treatment: dialysis intensification
  • Heparin during dialysis can worsen → heparin-free or citrate-based

284.3.3.6 Post-Cardiac Injury Syndromes

  • Dressler syndrome (post-MI, 2-10 wk): autoimmune; treatment same as pericarditis
  • Post-pericardiotomy syndrome (post-cardiac surgery): same physio
  • Post-traumatic (penetrating, blunt)

284.3.3.7 Radiation Pericarditis

  • Early (during/after radiation): acute pericarditis
  • Late (10-30 years post): constrictive
  • Common in old chest radiation (Hodgkin’s, breast, lung)
  • Pericardiectomy if constrictive

284.3.3.8 Pericardiectomy Pearls

  • Complete > partial
  • Bilateral phrenic nerve preservation
  • 5-15% perioperative mortality
  • Symptoms improve over weeks-months
  • May have post-op LV dysfunction (atrophy from chronic constriction)

284.3.3.9 Cardiac MRI in Pericardial Disease

  • T2 hyperintensity = edema (active inflammation)
  • Late gadolinium enhancement of pericardium
  • Cine for ventricular interdependence
  • Thickness assessment
  • Differentiates myopericarditis

284.3.3.10 Pericardiocentesis Pearls

  • Subxiphoid approach: angle 30° toward L shoulder
  • Echo-guided preferred
  • Confirm position with agitated saline
  • Hemorrhagic fluid: aspirate slowly, send for clotting (compare to peripheral)
  • Complications: arrhythmia, pneumothorax, hepatic puncture, ventricular puncture

284.3.4 Pearls

  • Diagnosis: 2 of 4 (pain + rub + ECG + effusion)
  • Treatment: NSAID + colchicine 3 mo; rilonacept for refractory recurrent (RHAPSODY)
  • Tamponade: emergency pericardiocentesis; Beck triad, pulsus paradoxus, RA/RV collapse on echo
  • Constrictive vs restrictive: tissue Doppler e’ preserved/↑ in constrictive
  • TB pericarditis: common globally; effusive → constrictive; ADA helpful
  • Pericardiectomy for chronic constrictive — definitive but high morbidity
  • Avoid steroids first-line in acute pericarditis (↑ recurrence)