https://orcid.org/0000-0001-5395-1887
Hypertrophic cardiomyopathy (HCM) sometimes concurs with mitral leaflet elongation, occasionally causing systolic anterior motion (SAM) and severe left ventricular outflow tract obstruction (LVOTO) in conjunction with septal thickness. Mitral chordal rupture sometimes occurs in patients with HCM due to myxomatous changes in the mitral leaflets. We report a case of obstructive HCM with an elongated mitral leaflet that subsequently prolapsed due to the chordal rupture. Thereafter, the prolapse diminished the SAM. The four-dimensional flow cardiac magnetic resonance (4D-flow CMR) imaging enabled the comparison of haemodynamic changes before and after the chordal rupture.
A 67-year-old man with HCM had LVOTO, with a peak pressure gradient (PG) of 48 mmHg and moderate mitral regurgitation due to SAM. After a new-onset chordal rupture of the posterior mitral leaflet (PML), the peak PG decreased to 9 mmHg and his SAM diminished. The streamline images from 4D-flow CMR imaging (Supplementary data online, Figure S1 and Videos S1 and S2) revealed two turbulent flows over and below the mitral leaflets in late diastole (yellow arrows). Before the rupture, the turbulent flow below the PML was dominant in early-peak systole (white arrows), which might have pushed the leaflets up and caused the SAM. Contrarily, after the rupture, these flows offset each other and disappeared in peak systole (red arrow). That might have prevented the SAM and LVOTO. His symptom improved from New York Heart Association Class II to I after the chordal rupture.
Our findings suggest that 4D-flow CMR images enable the visualization of the detailed mechanism of SAM and its disappearance.
Supplementary data are available at European Heart Journal – Cardiovascular Imaging online.
Funding: None declared.
Data Availability
The data underlying this article will be shared on reasonable request to the corresponding author.
Author notes
Conflicts of interest: None declared.
