Pericarditis, Tamponade, Myocarditis & Infective Endocarditis

Triage, Hemodynamic Profiling & IV Access: Place on continuous ECG monitor, pulse oximetry, and cycle NIBP q2min. Insert two large-bore (16G–18G) peripheral IV cannulae. Draw 3 sets of blood cultures (20 mL per set from separate venipuncture sites) antibiotics if febrile/septic [1,2].

Tamponade Preload Bridge: Rapidly infuse 250–500 mL of isotonic crystalloid (Lactated Ringer's or 0.9% NaCl) via pressure bag over 10–15 min ONLY if hypovolemic/hypotensive (SBP < 90 mmHg) while preparing pericardiocentesis tray [1,3].

Transiently elevates Mean Systemic Filling Pressure (MSFP) above elevated intrapericardial pressure (peri) to maintain right atrial venous return (VR = [MSFP − RAP] / v) for 10–15 min until needle decompression [1,3].

12-Lead ECG & Immediate Bedside POCUS (RUSH / Cardiac Views): Obtain 12-lead ECG (assess for diffuse concave ST elevation + PR depression, electrical alternans, or new AV block). Perform 4-view cardiac POCUS (Subxiphoid, Parasternal Long Axis [PLAX], Apical 4-Chamber [A4C], IVC) [1,3].

Inopressor Bridge in Obstructive Tamponade / Fulminant Myocarditis Shock: Start Norepinephrine 0.05–0.5 mcg/kg/min IV (3.75–37.5 mL/hr of 64 mcg/mL solution for 80 kg). Add Epinephrine 0.05–0.3 mcg/kg/min (3.75–22.5 mL/hr) or Dobutamine 2–20 mcg/kg/min if severe biventricular contractile failure (myocarditis) [1,4].

α₁/β₁ agonism maintains coronary perfusion pressure (CPP = DBP − LVEDP) and preserves compensatory sinus tachycardia. Never slow the heart rate in tamponade or cardiogenic shock (CO = HR × SVfixed) [1,3,4].

Prepare Emergency Ultrasound-Guided Pericardiocentesis (If Obstructive Shock): Position patient at 30°–45° semi-recumbent (pools fluid anteriorly/inferiorly and prevents orthopneic arrest). Prep left chest/subxiphoid with chlorhexidine; drape with sterile probe cover; ready 18G 8–15 cm spinal/pericardiocentesis needle, J-wire, and 6Fr–8Fr pigtail catheter [1,3].

Awake Local Anesthesia / Ketamine Dissociation: Infiltrate skin and rib periosteum (superior border of rib) with 5–10 mL of 1% Lidocaine. If agitation mandates systemic analgesia, give Ketamine 0.25–0.5 mg/kg (20–40 mg) IV slow push over 2 min [1,3].

Avoids supine positioning and avoids positive-pressure intubation (RSI), which spikes intrathoracic pressure, crushes venous return, and precipitates immediate PEA cardiac arrest in tamponade [1,3].

Execute Needle Decompression OR Administer Empiric IE Bactericidal Therapy:
• Tamponade: Advance needle under real-time POCUS (Apical or Parasternal in-plane view), aspirate 50–100 mL to restore pulse/BP, place pigtail catheter [1,3].
• Septic IE / Acute Valvular Rupture: Initiate dual/triple bactericidal IV antibiotics immediately after blood cultures drawn [2].

Empiric Native Valve IE (Acute/Severe): Vancomycin 25–30 mg/kg (2,000 mg for 80 kg) IV over 90 min + Cefepime 2 g IV over 30 min (or Ceftriaxone 2 g IV + Nafcillin/Flucloxacillin 2 g IV q4h) [2,5].
Prosthetic Valve IE (< 1 yr): Vancomycin 25–30 mg/kg IV + Rifampin 300 mg IV/PO q8h + Gentamicin 1 mg/kg IV q8h [2,5].

Immediate decompression shifts the interventricular septum back to neutral, restoring left ventricular preload and stroke volume [1,3]. Bactericidal synergy penetrates avascular fibrin-platelet endocardial vegetations [2,5].

Targeted Anti-Inflammatory Therapy OR Mechanical Circulatory Support Activation:
• Uncomplicated Acute Pericarditis: Administer high-dose NSAID + Colchicine [1,6].
• Fulminant Myocarditis / Acute IE Valve Rupture: Activate VA-ECMO / Impella team or Cardiothoracic Surgery [1,2,4].

Acute Pericarditis First-Line: Ibuprofen 600–800 mg PO q8h (or Aspirin 750–1000 mg PO q8h) + Colchicine 0.5 mg PO BID (0.5 mg PO daily if weight < 70 kg) + Pantoprazole 40 mg PO daily [1,6,7].
Acute Severe AR/MR from IE: Nitroprusside 0.3–3 mcg/kg/min IV (if SBP > 90 mmHg) to reduce regurgitant fraction as a bridge to OR [2].

Colchicine binds β-tubulin to block neutrophil microtubule polymerization and NLRP3 inflammasome activation, cutting pericarditis recurrence by 50% (ICAP Trial) [1,6,7].