Myocardial Crypts on Ultrasound in a Young Female with Exertional Syncope

A 20-year-old female with no past medical history presented to the emergency department (ED) after an episode of exertional syncope. Physical examination, vital signs, and electrocardiogram were unremarkable. Point-of-care ultrasound revealed abnormal invaginations in the interventricular septum. Laboratory evaluation was significant for markedly elevated troponin concerning for cardiac arrest. She was admitted to cardiology with suspicion for genetic cardiomyopathy. The patient underwent placement of an implantable cardioverter defibrillator after cardiac magnetic resonance imaging redemonstrated the septal invaginations known as myocardial crypts. Genetic studies later revealed sarcomere gene mutations associated with hypertrophic cardiomyopathy.

Myocardial crypts, which are invaginations within the myocardium, are considered early morphological markers for hypertrophic cardiomyopathy and may precede the development of overt hypertrophy. The presence of myocardial crypts and syncope is highly concerning for evolving hypertrophic cardiomyopathy. In this case, identifying myocardial crypts on ED point-of-care ultrasound, in conjunction with clinical context, facilitated further confirmatory diagnostics and timely intervention with placement of an implantable cardioverter defibrillator.