SCMR 22nd Annual Scientific Sessions
Description of Clinical Presentation:
A 55-year-old man presented with complaints of exertional dyspnea, facial and lower extremity edema to the outpatient clinic. After the administration of diuretics, his edema was improved but he still had dyspnea. The patient was then referred to our hospital for the further evaluation. Chest X-ray showed increase of cardiac silhouette. Electrocardiogram (ECG) shows sinus rhythm and inverted T waves in II, III, aVF and V1-5. Echocardiography showed a dilated right ventricle (RV) and moderately impaired RV and left ventricular (LV) function. Chest CT showed a dilated RV outflow tract and RV without lymphadenopathy. Coronary arteries were normal at coronary angiography. Endomyocardial biopsy (EMB) was inconclusive. Cardiac MRI showed dilated RV with impaired RV function (RVEDVI 197 m/m2, RVEF 12%) and dilated LV with impaired LV function (LVEDVI 122ml/m2, LVEF 20%). Diffuse LGE was shown in RV walls and predominantly subepicardial LGE was shown in basal LV walls and mid anterior, inferoseptal and inferior LV walls. The LGE pattern was non-ischemic and raised concern for cardiac sarcoidosis but screening for laboratory investigations for sarcoidosis were negative. Late potential on signal-averaged ECG was positive. These findings fit with the diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) according to the task force criteria. This patient was diagnosed as ARVC. Two years later, this patient had syncope with sustained ventricular tachycardia (VT) requiring cardioversion. He was reevaluated for the cause of VT and biventricular dysfunction.
Diagnostic Techniques and Their Most Important Findings:
A myocardial SPECT scan showed perfusion defects in the inferior and septal segments. The second cardiac MRI demonstrated dilated RV and LV with biventricular dysfunction (RVEDVI 218 m/m2, RVEF 11%, LVEDVI 110ml/m2, LVEF 18%). The mid inferior and apical walls of LV were dyskinetic. Patchy increased T2 signal was shown in basal and mid septal walls. The distributions of LGE were almost the same as those of the previous study. EMB of RV guided by LGE of CMR and electro-anatomical mapping provided the histological proof of non-caseating granuloma. These findings were compatible with cardiac sarcoidosis. To evaluate the activity, FDG-PET/CT was performed. PET/CT demonstrated intense FDG uptake throughout the myocardium of RV and patchy focal FDG uptake of anterior, septal and inferior walls of LV. Abnormal FDG uptake was also identified in mediastinal lymph nodes and lung.
Learning Points from this Case:
This case diagnosed with ARVC was finally found to have cardiac sarcoidosis. This case demonstrates overlapping features of cardiac sarcoidosis with those seen in ARVC. It is important to be aware that RV cardiac sarcoidosis may mimic ARVC and patients with ARVC might have cardiac sarcoidosis. The diagnosis of sarcoidosis was confirmed by EMB and supported by the PET/CT findings.