SHM Converge Scientific Abstract ePoster Gallery-Necrotizing Autoimmune Myositis - A Rare Etiology of Advanced Cardiomyopathy

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A 40-year-old man with biopsy-proven necrotizing autoimmune myositis (NAM) on abatacept presented with two days of worsening shortness of breath. On arrival, he was tachycardic with a heart rate of 170/min. Labs showed elevated troponin, creatine phosphokinase, and aldolase, suggesting active muscle and possible cardiac injury. ECG demonstrated new atrial flutter with variable conduction and an underlying right bundle branch block. CTA of the chest also revealed multiple right-sided pulmonary emboli.<br /><br />He was treated with amiodarone and anticoagulation with low-molecular-weight heparin. Although he initially improved, he became hypotensive within 24 hours and required pressor support. TTE then showed severe new cardiomyopathy with an LVEF of 10%. After attempted transesophageal echocardiography and cardioversion, he suffered cardiac arrest and required escalating inotropic support and ECMO. Coronary angiography showed non-obstructive coronary arteries. Given the rapidly progressive course, cardiac involvement from NAM was suspected. Cardiac MRI showed diffuse late gadolinium enhancement, supporting myocardial involvement.<br /><br />He was treated with pulse-dose steroids and cyclophosphamide. Over the next three weeks, his cardiac function improved dramatically, with LVEF recovering to 55%, and he was successfully weaned from ECMO. He was discharged four weeks later on steroids and cyclophosphamide to a long-term acute care facility.<br /><br />This case highlights that NAM, like other idiopathic inflammatory myopathies, can cause serious cardiac complications including arrhythmias and severe heart failure. Early recognition, telemetry monitoring, and prompt immunosuppressive therapy may be lifesaving and improve prognosis.

Asset Subtitle

Aleesha Kainat

Meta Tag

Author List Aleesha Kainat, Anjana Chandrasekhara Pillai, Corey Rearick, Rahul Chaudhary

Category Clinical Vignettes

Concept Statin-induced necrotizing autoimmune myopathy

Concept Cardiac Involvement

Concept Cardiac Arrhythmia

Concept Acute Heart Failure

Concept Cardiogenic Shock

Distinguished Non-Finalist

Presenter Organization Department of General Internal Medicine, University of Pittsburgh Medical Center, McKeesport

Presenting Author Aleesha Kainat

Track Adult

Keywords

necrotizing autoimmune myositis

cardiac involvement

atrial flutter

pulmonary embolism

cardiomyopathy

cardiac arrest

ECMO

cardiac MRI

immunosuppressive therapy

heart failure

Statin-induced necrotizing autoimmune myopathy

Cardiac Involvement

Cardiac Arrhythmia

Acute Heart Failure

Cardiogenic Shock