NPPB and Myocardial fibrosis: Long-term childhood cancer survivors exposed to cardiotoxic therapy show subtle impairment of cardiovascular function best detected by decreased exercise capacity, elevated NTproBNP levels, increased global longitudinal strain on speckle tracking, and abnormal mitral valve annular septal tissue doppler velocities in the absence of gross morphological changes, such as myocardial fibrosis on CMR, or echocardiographic decreased ejection fraction, enlarged left ventricular chamber sizes or left atria.