Exercise induces changes in mitral valve geometry

In patients with mitral regurgitation (MR), isometric handgrip exercise (IHE) seems to alter mitral valve (MV) geometry, triggering MR exacerbation regardless of its aetiology, a recent study has found.

Seventy-six patients participated in the study, of whom 40 (median age 71 years, 63 percent men) had functional MR (FMR) and 36 (median age 68 years, 61 percent men) had degenerative MR (DMR). All participants underwent 3D transoesophageal echocardiography (TEE) combined with IHE, during which MV geometry and the 3D vena contracta area (VCA) were measured, as well as at baseline.

The researchers recorded significant impacts of IHE on both haemodynamic factors and 3D MV geometry, which differed according to MR aetiology. For instance, both FMR and DMR groups saw significant elevations in systolic and diastolic blood pressure, as well as in heart rate, following IHE (p<0.001); the diastolic BP changes were stronger in the DMR group.

In terms of geometry, IHE triggered increases in tenting height and tenting volume in the FMR group (p<0.001 for both), while decreasing annular height and tenting volume in DMR participants (p<0.02 for both). Moreover, IHE significantly exacerbated 3D VCA in both MR groups, but had a significantly stronger impact on FMR patients (p<0.0001).

Multivariate analysis found tenting height (p=0.014) and baseline 3D VCA (p=0.02) as significant correlates of the change in 3D VCA during IHE in the FMR group. In DMR patients, only flail width (p=0.007) had such an association.

“Our findings establish the determinants of exercise-induced MR differed between MR aetiologies, and highlight the importance for simultaneous assessment of MR severity and MV geometry during exercise in heart failure patients with moderate or greater MR,” the researchers said.