Late onset apical hypertrophic cardiomyopathy: a case report

Apical Hypertrophic Cardiomyopathy: A Fatal yet Underappreciated Variant of Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a group of diseases affecting the left ventricle heart muscle that share a common feature of left ventricular hypertrophy without associated cardiac or systemic disorder. It was found to have a genetic basis with autosomal dominant mutations in the sarcomeric protein genes. Apical HCM is a rare subtype and underappreciated variant of HCM that primarily affects the apex of the heart. Apical HCM is dissimilar to classic HCM, with more challenges in diagnosis and inconsistent clinical course than other types. We report a case of a 91-year-old female who presented with a syncopal episode. Workup revealed atypical nonclassic features. Her transthoracic echocardiogram revealed a "spade-like" configuration of the left ventricular cavity at end-diastole consistent with apical hypertrophic cardiomyopathy. The remaining of her workup was consistent with the apical hypertrophic cardiomyopathy as a reason for the syncopal episode on presentation. Apical HCM is a distinct form of HCM that requires more attention among clinicians. In our case, the patient ended up having an implantable cardioverter defibrillator (ICD) for secondary prevention and a prescription of a beta blocker with a good outcome in her case.

Left ventricular morphologic progression in apical hypertrophic cardiomyopathy

BACKGROUND

Left ventricular (LV) morphologic progression in apical hypertrophic cardiomyopathy (AHC) has not been well studied. We evaluated serial echocardiographic changes in LV morphology.

METHODS

Serial echocardiograms in AHC patients were assessed. LV morphology was categorized according to the presence of an apical pouch or aneurysm, and LV hypertrophic severity and extent; relative, pure, and apical-mid type defined as mild (<15 mm thickness) apical hypertrophy, significant (≥15 mm) apical hypertrophy, and both apical and midventricular hypertrophy, respectively. Adverse clinical events and late gadolinium enhancement (LGE) extent on cardiac magnetic resonance were evaluated for each morphologic type.

RESULTS

In 41 patients, 165 echocardiograms (maximal interval: 4.2 [IQR, 2.3-11.8] years) were evaluated. Morphologic changes were observed in 19 (46%) patients. Eleven (27%) patients displayed the progression of LV hypertrophy toward pure or apical-mid type. Five (12%) and 6 (15%) patients developed new pouches and aneurysms. Patients with progression tended to be younger (50 ± 15.6 vs 59 ± 14.4 years, P = 0.058) and had a longer period of follow-up (12 [5-14] vs 3 [2-4] years, P < 0.001). During a follow-up of 7.6 (IQR 3.0-12.1) years, 21 (51%) experienced clinical events. The relative, pure, and apical-mid types showed different LGE extents (2%, 6%, and 19%, P = 0.004). Patients with severe hypertrophic and apical involvement showed higher clinical event rates.

CONCLUSIONS

About half of AHC patients had a progression of LV morphology to more hypertrophic involvement and/or an apical pouch or aneurysm formation. Advanced AHC morphologic types were associated with higher event rates and scar burdens.