Mitral Regurgitation in Takotsubo Syndrome: A Comprehensive Narrative Review.

Takotsubo syndrome (TTS) is an acute, transient, non-ischemic cardiomyopathy marked by circumferential wall‑motion abnormalities that typically extend beyond a single epicardial territory. Although most patients recover left ventricular function within weeks, the acute phase can be destabilized by mechanical complications and cardiogenic shock. Mitral regurgitation (MR) in TTS is frequent and clinically consequential, arising from systolic anterior motion (SAM) with dynamic left ventricular outflow tract obstruction (LVOTO) or from leaflet tethering driven by apical or mid-ventricular ballooning in the absence of obstruction. These mechanisms demand divergent strategies because inotropes and afterload reduction that may help pump failure can aggravate obstruction, whereas preload reduction that aids congestion can worsen gradients if LVOTO is present. This review synthesizes epidemiology, mechanisms, imaging pathways, hemodynamic phenotypes, management, special contexts, outcomes, and research priorities of MR in TTS using only the provided peer-reviewed sources. Transthoracic echocardiography anchors diagnosis by identifying SAM, quantifying MR, and measuring left ventricular outflow tract (LVOT) or intracavitary gradients, while transesophageal echocardiogram (TEE), cardiovascular magnetic resonance imaging (CMR), left ventriculography, and myocardial contrast echocardiography (MCE) provide complementary insights when acoustic windows are limited or when postoperative differentials must be adjudicated. Right ventricular involvement denotes a higher‑risk phenotype with more functional regurgitation and worse short-term outcomes, reinforcing the need for meticulous preload and afterload management. In patients with obstruction, therapy focuses on beta-blockers, careful volume expansion, and vasoconstrictors to restore stability. For patients with tethering-dominant MR, the priority is decongestion and customized afterload reduction. If shock persists despite these measures, temporary mechanical circulatory support can be used to bridge patients to recovery.