Beyond Hypertrophy: A Case of Mid-ventricular Obstructive Hypertrophic Cardiomyopathy With Apical Sequestration.

Apical sequestration is an often overlooked manifestation of mid-ventricular obstructive hypertrophic cardiomyopathy (MVO-HCM), in which dynamic mid-ventricular obstruction creates an anatomically and functionally isolated apical chamber with impaired distal perfusion. We describe a patient with MVO-HCM who developed apical sequestration complicated by flow stagnation, ischemic injury, and a small mural apical thrombus. Transthoracic echocardiography showed marked mid-ventricular hypertrophy with systolic narrowing. At the same time, cardiac magnetic resonance provided a more comprehensive characterization by demonstrating a mechanically trapped apical chamber, mid-ventricular intramural fibrosis, a small apical thrombus, and transmural late gadolinium enhancement consistent with ischemic injury. Coronary angiography revealed no obstructive disease, supporting a mechanism of obstruction-related flow limitation rather than epicardial coronary pathology. This case underscores apical sequestration as a high-risk morphological and physiological variant of MVO-HCM. It highlights the value of multimodality imaging, particularly cardiac magnetic resonance, in identifying this uncommon presentation and guiding clinical management.