A Rare Case of Mass-Like Hypertrophic Cardiomyopathy

Mass-like hypertrophic cardiomyopathy (HCM) is a unique variant of HCM. HCM predominantly causes mid-ventricular, concentric hypertrophy, and asymmetric septal hypertrophy; however, focal hypertrophy mimicking a cardiac fibroma is rare. A 29-year-old female with a past medical history of recurrent orthostatic hypotension and syncope presented to the emergency department (ED) complaining of lightheadedness, dizziness, and generalized weakness associated with a syncopal episode. The patient reported a history of recurrent pre-syncope and syncope since her teenage years, as well as a family history of sudden cardiac death. Three years prior to her current presentation, the patient had an exercise stress test, 24-hour Holter monitor, and two echocardiograms that were unremarkable. Three weeks prior to presentation, the patient had a cardiac MRI that revealed focal mass hypertrophy of the basal anterior to mid anterior wall measuring up to 2.5 cm. In the ED, the patient was treated with intravenous fluid and beta-blockers; however, beta-blocker therapy had to be discontinued because the patient was experiencing presyncopal episodes and orthostatic hypotension. The patient was started on midodrine with partial improvement lightheadedness, dizziness, and presyncope. The patient was transferred to a tertiary center with the plan to do serial imaging and place an implantable cardioverter-defibrillator (ICD) if the focal mass thickness reached 3 cm and explore surgical intervention if symptoms worsened. Identifying and reporting anomalous variants of HCM is critical for optimal management of patient care and to improve outcomes.