Serum digoxin level measurement and acetyl strophanthidin tolerance testing yielded discordant results in 42% of titrations among patients on maintenance digoxin.
Observational (n=133)
How does acetyl strophanthidin tolerance testing compare with serum digoxin level measurement in assessing the degree of digitalization in patients on maintenance digoxin?
Acetyl strophanthidin titration testing frequently yields discordant results compared to serum digoxin levels, suggesting it may provide additional insight into optimal therapeutic glycoside dosing, especially in patients with severe valvular disease or advanced age.
Serum digoxin levels (SDL) were compared with tolerance for the rapidly acting cardiac aglycone, acetyl strophanthidin (AS). AS titration tests were performed on 133 patients with diverse cardiac disorders. All were receiving maintenance digoxin. Both exquisite AS sensitivity and tolerance for a 1.0 mg AS were associated with a wide range of SDL values. Concordance and discordance between the two methods in assessing degree of digitalization were evaluated by considering SDL of 1.4 ng/ml to be the mean value for patients without glycoside-induced cardiac arrhythmia. An SDL of 1.4 ng/ml with sensitivity to 1.0 mg AS or less constituted concordant responses. An SDL of 1.4 ng/ml with tolerance for 1.0 mg AS comprised discordant responses. In 60 of 144 (42%) AS titrations discordant results were observed. Severe pulmonic, coronary, and aortic valvular heart disease, as well as old age, contributed to unusual AS sensitivity. Titration with AS clarified pharmacologic quantification of SDL by providing insight into optimum therapeutic glycoside dose.
Klein et al. (Sat,) conducted a observational in Diverse cardiac disorders (n=133). Serum digoxin level measurement vs. Acetyl strophanthidin tolerance testing was evaluated on Discordant results between serum digoxin levels and acetyl strophanthidin tolerance. Serum digoxin level measurement and acetyl strophanthidin tolerance testing yielded discordant results in 42% of titrations among patients on maintenance digoxin.