Focal Myocardial Fibrosis Mimicking Hypertrophy in INOCA and the Energetic Cost of Supranormal Ejection Fraction.

BACKGROUND

Coronary vasospasm is a major cause of ischemia with nonobstructive coronary arteries; however, its long-term structural and energetic consequences on the myocardium remain under-recognized.

CASE SUMMARY: A 72-year-old postmenopausal woman presented with chest discomfort and electrocardiographic findings suggestive of myocardial ischemia. Acetylcholine provocation testing revealed epicardial and microvascular coronary spasm. Cardiac magnetic resonance revealed focal late gadolinium enhancement in the interventricular septum, confirming replacement fibrosis mimicking hypertrophy. Additionally, the patient showed a supranormal ejection fraction of 79% and a markedly reduced end-systolic volume, indicating a hyperdynamic small left ventricle.

DISCUSSION: This case demonstrates that recurrent coronary spasm is not benign and can be related to irreversible myocardial fibrosis and maladaptive hyperdynamic remodeling, increasing the risk of diastolic dysfunction and heart failure.

TAKE HOME MESSAGES: Recurrent coronary spasm may contribute to focal myocardial fibrosis. Left ventricular ejection fraction should be interpreted with end-systolic volume to identify hyperdynamic states.