3-Year Follow-Up of Radiation-Associated Changes in Diastolic Function by Speckle Tracking Echocardiography

Background: Radiation therapy (RT) results in myocardial changes consisting of diffuse fibrosis, which may result in changes in diastolic function. Objectives: The aim of this study was to explore RT-associated changes in left ventricular (LV) diastolic function. Methods: Sixty chemotherapy-naive patients with left-sided, early-stage breast cancer were studied with speckle tracking echocardiography at 3 time points: prior to, immediately after, and 3 years after RT. Global and regional early diastolic strain rate (SRe) were quantified, as were parameters of systolic function. Results: Regional changes in SRe, particularly the apical and anteroseptal segments, were observed over time and were more evident than global changes. The apical SRe declined from a median of 1.24 (interquartile range: 1.01 to 1.39) s-1 at baseline to 1.02 (interquartile range: 0.79 to 1.15) s-1 at 3 years of follow-up (p < 0.001). This decline was associated with the left ventricular maximal radiation dose (β = 0.36, p = 0.007). The global SRe was