"Clinical presentation is variable in severity, ranging from asymptomatic to cardiogenic shock or haemodynamic instability including sudden cardiac death 9,10. Common symptoms include chest pain (including pericarditic or pseudo-ischaemic), dyspnoea, fatigue, syncope and fever 5,6. New-onset heart failure and arrhythmias are associated with a worse prognosis 4,6."
"myocardial thickening – suggesting myocardial oedema"
"cine SSFP:"
"T2/STIR black blood:"
"T1 mapping:"
"T2 mapping: regional or diffuse increase in T2 relaxation time"
"IRGE: non-ischaemic pattern late gadolinium enhancement often subepicardial or patchy midwall"
"FDG-PET is an alternative noninvasive diagnostic tool 1,18, especially in patients, in whom an autoimmune disease is suspected and shows increased 18F-FDG uptake that can be focal or diffuse or focal on diffuse 18."
"The annual incidence was estimated to be 21-24 of 100000 4."
"Laboratory findings are usually characterised by elevated high-sensitivity troponin or other cardiac enzymes such as creatinine kinase-MB, and inflammatory markers such as ESR and CRP 1. Leucocytosis or eosinophilia might be present in some cases 1. A viral titre may be positive."
"ST-segment elevation or non-elevation, T wave inversion"
"AV block (first to third degree)"
"prolongation of the QRS complex duration (>120 ms) - poor prognostic factor 10"
"A setting with evidence of cardiomyocyte injury, necrosis or cell degeneration associated with an infiltration of inflammatory cells at the cardiomyocyte circumference in the myocardium indicates acute or chronic active myocarditis as per the Japanese 2023 JCS guidelines 2."
"cine SSFP:"
"Endomyocardial biopsy should be considered in the setting of severe heart failure and cardiogenic shock, high-grade AV block, severe ventricular arrhythmias or where myocarditis has therapeutic implications e.g. in the setting of fulminant myocarditis or suspected immune checkpoint inhibitor-associated myocarditis 1,2,18."
Expected headings
"Subtypes"
"Echocardiography"
"Signal characteristics"
"MRI"
"Clinical presentation is variable in severity, ranging from asymptomatic to cardiogenic shock or haemodynamic instability including sudden cardiac death 9,10. Common symptoms include chest pain (including pericarditic or pseudo-ischaemic), dyspnoea, fatigue, syncope and fever 5,6. New-onset heart failure and arrhythmias are associated with a worse prognosis 4,6."
"A setting with evidence of cardiomyocyte injury, necrosis or cell degeneration associated with an infiltration of inflammatory cells at the cardiomyocyte circumference in the myocardium indicates acute or chronic active myocarditis as per the Japanese 2023 JCS guidelines 2."
"presence, pattern and extent of late gadolinium enhancement"
"presence, location and extent of myocardial oedema"
"Notably, the presence of myocardial oedema characteristically evidenced on T2-weighted images or T2 mapping is classically a marker of acute disease and should be present in the setting of acute myocarditis 1,2, whereas its absence points to other differential diagnoses such as various cardiomyopathies or chronic myocarditis or inflammatory cardiomyopathy, where it can be absent 1,6,18."