1351128 - Unusual case of recurrence of hypertrophic cardiomyopathy

A 70 year old female with a history of subaortic membrane, asymmetric septal hypertrophy, and atrial fibrillation was evaluated for cardiac function.  In August of 2008, the patient underwent resection of subaortic membrane, septal myomectomy, and MAZE procedure at an outside facility. Post operatively, the septal wall thickness was reduced from 1.5 to 0.7 cm, and LVOT gradient was reduced from 74 to 0 mmHg. Follow up transthoracic echocardiogram in 2010 showed a normal left ventricular (LV) size and systolic function, with no evidence of septal hypertrophy or LVOT gradient.

Patient had a follow up cardiac MR in 2013 performed at our institution that showed normal LV size and anatomy.  Repeat cardiac MR in 2020 showed mildly dilated LV, normal LV systolic function, and normal LV mass. The basal anteroseptal thickness was top normal at 12 mm. There was also apical hypertrophy (13mm) which was clearly myocardium, and does not represent apical thrombus or endocardial fibroelastosis. There was no evidence of subaortic membrane or turbulent flow across the LVOT.  There was abnormal septal motion consistent with prior myomectomy.  Late gadolinium enhancement (LGE) imaging was normal. 

Patient continued to have symptoms of dyspnea and palpitations. Repeat cardiac MRI in August of 2022 performed at our institution showed a very clear pattern of apical-spade hypertrophic cardiomyopathy (HCM). LGE imaging was markedly abnormal, with substantial dense apical wall nearly homogeneous LGE uptake, consistent with subendocardial scar. In conjunction with the clear emergence of an apical-spade HCM, this pattern is distinctly atypical in such cardiomyopathies and is typically noted for its complete devoid of an LGE pattern except in very advanced cases.

In summary, this case highlights the potential of HCM to recur in a different anatomic pattern years after successful surgical myomectomy. In our case, patient initially had reverse septal variant hypertrophic cardiomyopathy. Post-op CMR showed successful resection of hypertrophied septum. Repeat CMR a decade later showed recurrence of HCM with LGE pattern now in apical configuration.

Diagnostic Techniques and Their Most Important Findings: CMR findings as described above

Learning Points from this Case: Hypertrophic cardiomyopathy can recur in a different anatomic variation after successful surgical myomectomy