Clinical application of new echo modalities in left ventricular dysfunction * Friday 10 December 2010, 14:00-15:30
Background: Epirubicin is a potent and widely used citotoxic drug, but its application is often limited by the cumulative dose-dependent cardiotoxicity. LV ejection fraction (EF) and fractional shortening (FS) are the most commonly used indices to demonstrate cardiac dysfunction. Since normal EF or FS can mask significant LV impairment, we hypothesized that LV systolic torsion and deformation represent better markers of epirubicin-induced subclinical cardiac dysfunction. Methods: 40 women with breast cancer (58+9 years), without known associated cardiac disease, scheduled to be treated with epirubicin-based chemotherapy, were assessed at baseline, and after 1 and 6 cycles of epirubicin (cumulative dose of 293+15 g/m2). Conventional echocardiography was used to assess LV geometry, EF and FS. 2D speckle tracking imaging was used to measure LV systolic rotation parameters: peak apical rotation (RotA), peak basal rotation (RotB), LV twist (LVT) (as the difference in LV rotation between apical and basal planes), and twist rate (LVTR); and also LV systolic deformation indices: radial strain (rS) and strain rate (rSR), and longitudinal strain (LS) and strain rate (LSR). Results: No changes in LV dimensions, EF, and FS were observed during follow-up. However, there were significant reductions in RotA, and consequently in LVT and LVTR, with no changes in RotB; and also a significant decrease of LV radial and longitudinal deformation found after the first cycle of epirubicin and persistent after the sixth cycle (see table). Univariate analysis showed that epirubicin cumulative dose was directly correlated with longitudinal strain and LV twist reduction after 6 months of treatment (r=0.59 and r=0.79; both p,0.01). Conclusion: LV torsion and deformation parameters, assessed by 2D speckle tracking imaging, detect subclinical LV dysfunction and, therefore, can be used to monitor epirubicin-induced cardiac dysfunction.