Left Ventricular Crypts in Arrhythmogenic Cardiomyopathy

BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) is characterized by fibrofatty myocardial replacement predisposing patients to arrhythmias and sudden cardiac death. CASE SUMMARY: We describe a 51-year-old man with syncope, characteristic changes on electrocardiogram, and a family history of sudden cardiac death. Imaging showed right ACM features in addition to multiple left ventricular (LV) crypts. Cardiac magnetic resonance imaging (CMR) confirmed the right ACM features and further revealed LV fibrosis corresponding to the crypts. The patient was diagnosed with biventricular ACM and received an implantable cardioverter-defibrillator for primary prevention. DISCUSSION: This case demonstrates that the detection of crypt-like LV wall invaginations in high-risk patients warrants CMR. LV wall fibrosis and thinning coinciding with the crypts confirm LV ACM. TAKE-HOME MESSAGES: ACM can present with biventricular involvement. In a high-risk patient with suspected ACM, LV crypts warrant CMR to help distinguish them from pathological LV wall fibrosis and thinning. LV crypts in high-risk patients warrant further future reporting.