Abstract
BACKGROUND: Eclipsed mitral regurgitation (MR) is a rare, reversible condition that leads to transient severe MR and acute heart failure in patients with preserved left ventricular (LV) ejection fraction. Its diagnosis is challenging due to its intermittent presentation, necessitating advanced imaging techniques to reveal the underlying pathology. CASE SUMMARY: We present a case of a 74-year-old female with recurrent severe MR associated with a non-obstructive lesion in the proximal left anterior descending (LAD) artery. Multimodality imaging played a pivotal role in diagnosing this condition, as conventional vasodilator stress tests failed to uncover the ischaemic mechanism. Exercise stress echocardiography and myocardial perfusion scintigraphy successfully demonstrated a small ischaemic region affecting the mitral valve apparatus, which triggered severe MR during physical exertion. This dynamic ischaemia, undetected by routine tests, was essential in diagnosing the pathophysiology behind the patient's recurrent MR. Following percutaneous coronary intervention (PCI) to the LAD, her symptoms resolved, confirming the ischaemic origin of the MR. DISCUSSION: This case underscores the critical role of multimodality imaging in revealing the pathophysiology of recurrent MR. Advanced imaging techniques, particularly under physiologic stress, are crucial for diagnosing dynamic ischaemia and its impact on valvular function. By identifying the ischaemic cause of MR, individualized treatment strategies, such as PCI, can be implemented, avoiding unnecessary valve surgery and improving patient outcomes.