The Mechanics of Left Ventricular Dysfunction in Patients with Churg-Strauss Syndrome
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BACKGROUND: Heart is frequently involved in Churg-Strauss syndrome (CSS). However, the mechanics of left ventricular (LV) dysfunction in CSS has not been studied. OBJECTIVE: To assess the mechanics of LV function and to characterize the contribution of longitudinal, circumferential and rotational deformation to LV dysfunction in CSS. METHODS: We enrolled 22 CSS patients (eight males, mean age 43.2 ± 9.5 years) in remission of their disease and 22 sex- and age-matched healthy subjects. All patients underwent conventional and two-dimensional speckle-tracking echocardiography. Global longitudinal, circumferential and rotational deformation parameters were calculated. RESULTS: CSS subjects demonstrated lower LV ejection fraction (EF) than controls (56.6 ± 15.0% vs 63.8 ± 3.4%; P < 0.05). When compared to those with LVEF ≥ 50% (n = 14), CSS patients with LVEF < 50% (n = 7) had decreased global peak-systolic longitudinal and circumferential strain/strain rate (all P < 0.001) and tended to have lower global peak-systolic radial strain (P = 0.05). There were no differences between these two subgroups in global peak-systolic radial strain rate and LV twist/torsion. When comparing individual systolic and diastolic parameters early diastolic longitudinal and circumferential strain rate demonstrated the highest correlation with corresponding global longitudinal and circumferential peak-systolic strain/strain rate (r < -0.80, P < 0.001 for all correlations). CONCLUSIONS: In CSS LV systolic dysfunction strongly correlates with longitudinal and circumferential, but not radial or rotational systolic components, indicating that impaired LV systolic function may result predominantly from impaired contraction of inner and middle, but not outer myocardial fiber layers. The spatial correspondence between systolic and diastolic deformation parameters suggests the similar impact of pathologic process on systolic and diastolic function in CSS.