Poster 042: Cardiogenic Shock from Fulminant Myocarditis in a 52-Year-Old: Clinical Course, Mechanical Support, and Post-Transplant Outcomes

Background: Fulminant myocarditis is a rare, severe inflammation of the heart causing cardiogenic shock and dangerous arrhythmias. It progresses rapidly, often needing mechanical support and transplantation. Diagnosis is difficult due to patchy involvement and biopsy limits. Early treatment with immunosuppression and support improves survival, as shown in this 52-year-old male case.

Methods: Clinical Evaluation: Initial presentation with syncope and exertional dyspnea prompted ECG, labs (including troponin, NT-proBNP, autoimmune markers), echocardiogram, and CTA to exclude pulmonary embolism.
Cardiac Imaging: Transthoracic echocardiogram (TTE) assessed left ventricular ejection fraction (LVEF) and wall motion abnormalities; cardiac MRI performed to evaluate myocardial edema and fibrosis using late gadolinium enhancement (LGE) and T2 mapping.
Invasive

Assessment: Coronary angiography excluded significant obstructive coronary artery disease.
Mechanical Support: Peripheral venoarterial extracorporeal membrane oxygenation (VA ECMO) combined with Impella 5.5 device (“EcPella”) instituted after cardiac arrest during MRI and hemodynamic collapse.
Medical Therapy: Pulse-dose intravenous methylprednisolone initiated for suspected fulminant myocarditis; arrhythmias treated with lidocaine, procainamide, and ATP; transcutaneous pacing followed by permanent pacemaker implantation for complete heart block.
Transplant Evaluation: Multidisciplinary team assessed for urgent orthotopic heart transplantation following failure to wean from ECMO.
Pathology & Genetics: Post-transplant native heart pathology analyzed; genetic testing performed to evaluate for contributory variants.

Outcome: The patient experienced rapid clinical deterioration with cardiogenic shock and high-grade conduction disturbances necessitating emergent mechanical circulatory support.
Despite maximal support including VA ECMO and Impella, refractory ventricular tachycardia and severely reduced LVEF ( < 10%) persisted.
Acute corticosteroid therapy was administered based on imaging findings suggestive of inflammatory myocarditis.
The patient was urgently listed as Status 1 for heart transplantation due to refractory shock and electrical instability.
Orthotopic heart transplantation was successfully performed; post-operative course complicated by primary graft dysfunction requiring ongoing ECMO support.
Gradual recovery ensued with normalization of cardiac function on echocardiographic surveillance by 2 weeks post-transplant.
Native heart pathology showed hypertrophic myocytes with patchy fibrosis but no active inflammatory infiltrates, consistent with steroid treatment effects and sampling limitations.
Genetic testing revealed a variant of uncertain significance, suggesting possible genetic predisposition.

Conclusion: This case demonstrates challenges in diagnosing and treating fulminant myocarditis with shock and conduction issues. Early combined mechanical support stabilized the patient. Cardiac MRI guided immunosuppression despite a negative biopsy. Multidisciplinary care enabled timely heart transplantation, highlighting the need for aggressive management and urgent transplant in refractory cases.