Cardiac magnetic resonance imaging reveals extensive biventricular fibrosis and inflammation challenging the diagnosis of ARVC.

Abstract

Sirs:A 53-year-old female was admitted with recurrent pal-pitations and syncope at rest. Her medical history includedarterial hypertension and atrial tachycardia and her familyhistory was negative for sudden cardiac death. The physicalexamination did not reveal any pathologic findings.On electrocardiogram, sinus rhythm with an atypicalright bundle branch block (RBBB) pattern with Q waves inlead V 1–3 and negative T-waves as well as epsilon wavesin lead V1 to V4 were found (Fig. 1, top). The coronaryangiogram did not show any relevant stenosis. Echocar-diography revealed mildly impaired left ventricular (LV)ejection fraction (EF) as well as significantly impaired rightventricular (RV) function and mild dilatation of the RVbody and outflow tract, though, areas of akinesia ordyskinesia could not be identified. The next day, the pa-tient’s previously reported symptoms could be correlated toincessant ventricular tachycardia (VT) with two differentmorphologies (Fig. 1, bottom), suggesting an origin in theRV (Fig. 1, bottom right). The VT could successfully beterminated by intravenous application of amiodarone. Ac-cording to the modified Task Force criteria for ARVC twomajor criteria [1]: repolarization disorder (negativeT-waves in V1-4 in the presence of RBBB) and depolar-ization disorder (epsilon waves in V1–3), as well as oneminor criteria, sustained VT of RV outflow tract con-figuration (left BBB morphology with inferior axis) weremet, leading to the diagnosis of ARVC.Cardiac magnetic resonance (CMR) imaging was per-formed for further substrate analysis and comprehensiveassessment of RV anatomy, structure, and function. CineCMR imaging revealed a mildly impaired LV function,whereas the RV function was significantly reduced withdyskinesia of the free wall (EF 33%), also significant RVdilatation was found (139 ml/qm). Late gadolinum en-hancement (LGE) images demonstrated areas of extensivefibrosis of the anterolateral RV wall and a significanttransmural fibrosis/necrosis of the anterior LV and non-transmural intramyocardial LGE of the LV septum withcorresponding focal edema in these regions and no evi-dence of fatty tissue infiltration in the LV and RV (Fig. 2,top left and right). Moreover, evidence of global myocar-dial hyperemia as a marker of myocardial inflammation onT1 weighted images (global early enhancement) could bedetected. Consequently, the CMR findings were consistentwith myocarditis as three diagnostic CMR criteria formyocardial inflammation are met: (1) irreversible my-ocardial injury in a non-ischemic regional distributionpattern in LGE images, (2) hyperemia/capillary leakage asdefined by an increased early gadolinium uptake and (3)global or regional edema [2]. Yet, all these criteria are non-specific to myocarditis and can occur in various conditions.One important differential diagnosis is sarcoidosis, wherethis pattern of pronounced LGE notably in the basal septumcan be found. However, there were no clinical or histo-logical signs of sarcoidosis, making this diagnosis veryunlikely.For further evaluation, biventricular endomyocardialbiopsy was conducted, revealing moderate diffuse fibrosis,histologic proof of chronic lymphocytic myocarditis and