Acute effect of adjunctive breast cancer radiotherapy on right ventricular systolic and diastolic function

Aim: Breast cancer radiotherapy has been shown to depress left ventricular (LV) function, but its effects of right ventricular (RV) function are largely unknown. Reduced RV systolic performance correlates with poor prognosis across broad spectrum of diseases. The aim of this prospective single center study was to investigate whether conformal 3D breast cancer radiotherapy has negative effect on RV systolic and diastolic function in the acute phase. Methods: Forty consecutive patients with early left-side breast cancer were evaluated before and immediately after radiotherapy. A comprehensive 2D echocardiographic examination was performed at each visit. Several measurements of RV function were performed including tricuspidal annular plane systolic excursion (TAPSE), pulsed tissue Doppler peak velocity at the lateral RV wall (S'), RV inflow and outflow analysis, valvular assessment and venous flow analysis. Results: Radiotherapy reduced TAPSE from a baseline value of 24.9±4.1 mm to 22.7±4.0 mm (p< 0.001). In keeping with this S' declined from 13.0±5.0 m/s to 12.3±4.4 m/s (p=0.086) and pulmonary flow velocity time integral (VTI) from 16.7±3.3 to15.9±2.5 (p=0.089), respectively. These changes were not related to LV systolic or diastolic changes. According to multivariate analysis the use of angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker may protect against these changes (p= 0.097). Conclusions: Modern 3D radiotherapy reduced RV systolic function. These early changes might progress in time, and continuous follow-up of cardiac function is warranted in radiotherapy patients. As a readily available and sensitive measurement TAPSE is as a practical tool for this purpose.