HFSA ePoster Library

In this case a 23 year old female patient was admitted to the intensive care unit (ICU) in January 2020 for veno-arterial extra-corporeal membranous oxygenation (ECMO) to manage cardiogenic shock and recurrent ventricular tachycardia (VT). She had no prior medical history or hospitalisations. Following a positive influenza B swab, elevated troponin I 37,656 ng/L with the clinical presentation, the patient was diagnosed with acute myocarditis. To out rule giant cell myocarditis an endomyocardial biopsy (EMB) was completed. EMB detected ‘vacuoles with cytoplasmic debris and glycogen particles’ consistent with Danon Disease (DD). This diagnosis was supported by subsequent genetic screening determining a LAMP2 mutation the causal mutation in DD. The patient’s echocardiogram showed severe concentric left ventricular hypertrophy (LVH) consistent with DD and a severely impaired ejection fraction (EF) of 35% (Image 1).The patient was closely monitored as an outpatient and initiated on goal directed heart failure medication. In January 2021 she was readmitted with decompensated heart failure. Troponin I was 12,369ng/L and NTProBNP 10,817ng/l. The admission echo showed a marked deterioration (EF<10%), increasing left ventricular dilatation (Image 1). Mixed venous saturation was 63%. Despite a successful discharge home, the patient was readmitted 6 weeks later with slow VT and cardiogenic shock. A mixed venous saturation was 45% prompting insertion of an intra-aortic balloon pump and the patient was listed on the heart transplant list. The time from index presentation to transplant listing was 425 days (14.2 months). After 3 days on the active list the patient had a successful orthotopic heart transplant (OHT) and discharged from ICU 3 days later. Following a final predischarge mixed venous saturation of 72% the patient was discharged home 28 days post OHT without any adverse complications. Conclusion:This case provides evidence supporting the theory that cardiomyopathies due to genetic abnormalities predispose towards myocarditis as evidenced by this patient. It highlights the importance in investigating potential genetic abnormalities in certain patients within the myocarditis population. Close surveillance of patients with a cardiomyopathy secondary to Danon disease is also paramount as it rapidly progressed to an advanced heart failure stage requiring OHT within 14 months of the patient’s initial presentation. Timely listing for heart transplant ultimately contributed towards a successful and timely post-operative clinical recovery.