Adriamycin cardiotoxicity and proton nuclear magnetic resonance relaxation properties

Present noninvasive techniques to detect Adriamycin (doxorubicin) cardiotoxicity rely on assessment of myocardial function rather than direct observation of change in tissue character. Proton nuclear magnetic resonance imaging may provide a unique means of characterizing the myocardium. The relaxation properties T1 and T2 are related to certain biophysical properties of tissue such as water, lipid, and macromolecular content and have considerable impact on the intensity observed in nuclear magnetic resonance images. In a model of chronic Adriamycin cardiotoxicity in rats, T1 values of excised hearts were elevated, relative to control, in rats with histologic evidence of chronic cardiotoxicity (651 msec vs 622 msec, p less than 0.05) and more so in rats with gross evidence of toxicity or heart failure (668 msec, p less than 0.005). No significant change in T2 was observed. This T1 prolongation increases as disease worsens, whereas water concentration did not change significantly. The results suggest that predictable prolongation in T1 occurs in association with cardiotoxicity. In conclusion, proton nuclear magnetic resonance imaging methods could provide a new means for assessing Adriamycin cardiotoxicity.