This is a 53-year-old Caucasian female with a history of hypertension, recent stroke, and obesity, who presented with chest pain. She had intermittent chest discomfort as a child and was told she had asthma; however, over the past few months, her chest pressure became more frequent and occurred both with activity and rest. Physical exam was unremarkable. EKG showed T wave inversions in precordial leads. Troponins were indeterminate. Transthoracic echocardiography showed possible left ventricular aneurysm, however given the patient’s large body habitus, definitive diagnosis could not be established. During admission, the patient was noted to have several pre-syncopal episodes with nonsustained ventricular tachycardia, the longest run lasting 23 beats. Left heart catheterization demonstrated no epicardial coronary artery disease. Left ventriculogram revealed a spade-like appearance concerning for apical variant of HCM. Cardiac MRI with gadolinium enhancement demonstrated a spade-shape silhouette of the left ventricle with apical hypertrophy and ventricular ectopy. These findings are consistent with apical hypertrophic cardiomyopathy (ApHCM).
The patient was started on metoprolol, received an implantable cardioverter defibrillator for primary prevention of sudden cardiac death, and was referred for genetic testing. In addition, given the genetic predisposition of ApHCM, the patient’s family members were also encouraged to undergo genetic testing and echocardiography screening. At 6-month follow up, the patient remains symptom free.
Discussion:
ApHCM is a relatively rare form of hypertrophic cardiomyopathy that predominantly affects the apex of the left ventricle and typically has a nonobstructive physiology. It has an incidence of 0.01-0.03% and was first described in Japan. Establishing an accurate diagnosis is critical, as appropriate management and genetic counseling can improve morbidity and mortality.
Conclusions:
ApHCM constitutes roughly 13-25% of all cases of hypertrophic cardiomyopathy in Japanese patients, however it is much less often described in non-Japanese populations; our patient was Caucasian. The data in western populations is limited, but recent studies suggest that the risk of sudden cardiac death, myocardial ischemia, stroke, and ventricular arrhythmias is comparable to patients with other variants of hypertrophic cardiomyopathy such as hypertrophic obstructive cardiomyopathy. Thus when formulating a differential diagnosis for chest pain, it is critical to include apical and other variants of hypertrophic cardiomyopathy as part of that differential, as appropriate management can prevent these devastating sequelae. Furthermore, when screening tests such as echocardiography cannot adequately establish the diagnosis of ApHCM, cardiac MRI or invasive hemodynamic testing is necessary to establish or refute the diagnosis. The present case illustrates these points.