Complete Resolution of Left Ventricular Outflow Tract Obstruction After Spontaneous Mitral Valve Chordal Rupture in a Patient With Hypertrophic Cardiomyopathy

Abstract

Graphical abstract

Different mechanisms of mitral regurgitation in hypertrophic cardiomyopathy: A clinical case and literature review

“…While a higher prevalence of chordal rupture (5.4%) has been reported in a small surgical series (12), a larger cohort of HCM patients showed that chordal rupture is a rare event in HCM (1%) (11). From a literature search, we found 26 cases of HCM with ruptured chordae tendineae (Table 1) (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27).…”

“…The currently most accredited theory about the flail occurrence in HCM is that in patients with a genetically induced chordae/leaflets elongation, the traction induced by the drag forces through the narrowed LVOT may provoke the chordae rupture by itself ( 11 ). In fact, before rupture, almost all patients present mitral SAM and significant LVOT resting obstruction, which disappears in some cases after the flail appearance ( 11 – 13 , 15 , 20 , 21 , 23 , 26 ). Decrease or disappearance of mitral SAM and LVOT obstruction after chordal rupture highlights the potential role of the sub-valvular apparatus as a cause of obstruction in HCM, while ventricular dilatation, due to significant MR, may expand the outflow tract reducing the drag forces.…”

“…Hence, in cases like these, the reduction of the LVOT gradient may partly explain the paucity of symptoms in some patients, despite a severe MR appearance ( 11 ). The rupture of chordae tendineae in patients with narrowed LVOT can cause a lack of support of the AML, shifting the coaptation more posteriorly with the resolution of SAM and LVOT obstruction ( 26 ). Chordal rupture in HCM is rare and occurs more often in male-aged patients with obstructive disease and more frequently involves PML than AML ( 11 , 12 , 26 ).…”

“…The rupture of chordae tendineae in patients with narrowed LVOT can cause a lack of support of the AML, shifting the coaptation more posteriorly with the resolution of SAM and LVOT obstruction ( 26 ). Chordal rupture in HCM is rare and occurs more often in male-aged patients with obstructive disease and more frequently involves PML than AML ( 11 , 12 , 26 ). Although both AML and PML are elongated in HCM, PML elongation is usually less important than AML elongation, suggesting that insufficient elongation of PML could promote rupture, while the significant elongation of the AML might prevent chordal rupture ( 11 ).…”

“…One is the negative effect of acute and severe MR, which affected first reported cases in the literature, with rapid hemodynamic deterioration due to acute/severe MV dysfunction, requiring urgent surgical treatment. The other one is the positive effect due to LVOT obstruction relieving with the achievement of clinical stability and reduced exertional dyspnea despite severe MR and abnormal LV wall thicknesses ( 21 , 26 ).…”