[Is there a correlation between changes in the electrocardiogram and high serum digoxin levels in the aged?]

In a group of 84 patients aged 65 to 89 years with the high serum digoxin levels, electrocardiograms, as well as serum creatinine and serum potassium levels were analysed. In an electrocardiogram, a rhythm and conduction disturbances, PR interval, PTQ index, corrected QT interval, both a corrected QT interval I using the second root from a heart frequency and a corrected QT interval II using the third root from a heart frequency were studied. A rhythm disturbances were seen in 37% and a conduction disturbances in 39% of the patients, but no changes were observed in 24% of the patients. There was no correlation between serum digoxin levels and the PR interval. There was a slight correlation between serum digoxin levels and the PTQ index, and no correlation could be demonstrated between serum digoxin levels and a corrected QT interval I as well as a corrected QT interval II. Also, no correlation was evident between serum digoxin levels and serum creatinine levels, although many of those patients suffered from chronic renal failure. In an analysis of the influence of digoxin on the heart, electrocardiographic changes together with serum digoxin levels and serum potassium levels have to be followed. Only one of these parameters is not enough for the analysis of the effect of digoxin on the heart. It is concluded that clinical examination is most important in the analysis of digoxin action.