The role of left ventricular long axis contraction in patients with asymptomatic non-ischemic mitral valve regurgitation and normal systolic function

BackgroundSeveral indices have been proposed in order to better evaluate chronic mitral regurgitation, however, none of them is unique, thus underlying the diagnostic deficiency. We aimed to investigate the role of long axis contraction in both ventricles in patients with non-ischemic asymptomatic mitral regurgitation (MR).MethodsEighty-nine patients (40 men, mean age 59.9 ± 13.5 years) with non-ischemic asymptomatic MR along with 50 healthy controls were studied. An echocardiographic, including tissue Doppler imaging study, an exercise radionuclide cineangiography and a cardiac catheterization were also performed.ResultsFifty of 89 patients (56.2%) had a normal response of left ventricular (LV) ejection fraction on exercise. LV end-diastolic diameter and volume index were significantly higher in patients with an impaired LV response. Moreover, systolic wave maximal velocity and systolic wave slope both at the lateral wall and at the inter-ventricular septum were significantly lower in patients with an impaired LV response. Systolic wave maximal velocity at the lateral wall was the index that best predicted LV response to exercise; while a cutoff value of 9.5 cm/s predicted an impaired LV response with a sensitivity of 96% and a specificity of 100%. MR as defined by the width of vena contracta, was mild/moderate in 78% of patients with a systolic wave maximal velocity at the lateral wall > 9.5 cm/s and severe in 69.2% of patients with a velocity < 9.5 cm/s.ConclusionIn patients with asymptomatic non-ischemic MR, the evaluation of LV long axis contraction at rest can unmask a subnormal LV functional status.