Case Report: Multimodal imaging diagnosis of arrhythmogenic cardiomyopathy complicated with thrombosis

Background Arrhythmogenic Cardiomyopathy (ACM) is an inherited cardiomyopathy, and concomitant intracardiac thrombosis is a relatively rare clinical complication, whose pathogenesis is linked to blood flow stasis, endothelial injury and impaired cardiac function. Timely and accurate diagnosis and standardized treatment of this complication remain critical to avoid embolic adverse events. Case summary We present a case of a 37-year-old Asian female patient with ACM complicated with multiple thrombi at the right ventricular apex. She was hospitalized with a 3-month history of recurrent chest tightness and dyspnea aggravated in the latest half month. The electrocardiogram showed sinus rhythm with complete right bundle branch block, marked right axis deviation, ST-segment depression and T-wave inversion in leads V1–V3, premature ventricular complexes, and prolonged QT interval, which may suggest elevated right ventricular pressure load; laboratory examinations suggested cardiac dysfunction. Transthoracic echocardiography detected right ventricular dilatation, diffuse apical trabeculation and mural thrombus. Cardiac magnetic resonance further verified abnormal right ventricular wall motion, non-enhanced intracardiac thrombus and late gadolinium enhancement supporting the diagnosis of ACM. Discussion Transthoracic echocardiography enables early identification of cardiac structural lesions and thrombi, whereas cardiac magnetic resonance provides comprehensive evaluation of myocardial pathological changes. Combined application of the two imaging modalities is indispensable for confirming ACM with intracardiac thrombus. Early standardized anticoagulation combined with holistic therapy effectively lowers embolism risk and optimizes long-term prognosis. Clinicians ought to reinforce regular screening and targeted intervention for this rare thrombotic complication in ACM patients. Take home messages Transthoracic echocardiography serves as a convenient first-line screening tool for detecting right-ventricular morphological abnormalities and intracardiac thrombus. The mechanism of thrombus formation in biventricular-involved ACM with predominant right-ventricular lesions may be speculated with reference to Virchow's triad. Post-discharge imaging follow-up verified thrombus resolution after timely anticoagulation.