Electrocardiogram QRS voltage changes in adriamycin cardiomyopathy

Having observed a marked decrease in electrocardiogram QRS limb lead voltage in patients with adriamycin cardiomyopathy, an attempt was made to quantitate these changes in 17 adriamycin cardiomyopathy patients. Using only the 6 limb lead QRS complexes, measurements were made of: the total absolute deflection of the QRS; and the algebraic sum of the positive and negative deflections. Comparisons were made of the QRS voltages in both the pretherapy stage and at the time of cardiomyopathy. The median percent decrease in A between those intervals was 55% with 16/17 (94%) having ≥ 40% decrease. The median decrease in B was 74% with 14/17 (82%) having ≥ 40% decrease. Patients who developed cardiomyopathy at higher total cumulative doses of adriamycin had a greater percent decrease in their QRS complexes measured either as A or B than patients receiving lower doses. The correlation coefficient is highly significant (p<0.02). Currently, a similar group of patients who did not develop cardiomyopathy are being evaluated to determine if the QRS changes are predictive, and to see if other factors, such as prior cardiac disease, age, sex, prior radiation therapy and other chemotherapy may increase their risk of adriamycin cardiomyopathy. At present, changes in A and/or B ≥ 40% associated with any clinical cardiac abnormality are being used by the authors as an indication to withhold further adriamycin.