An electronic circuit capable of integrating the electrocardiogram is described. The net areas of the QRS complex, the T wave and of the entire ventricular complex, QRS-T, in the standard leads may be estimated by measurement of the length of two vertical lines in each of the integrated records. The manifest areas of QRS, T and the gradient (QRS-T) with the orientation of these vectors are easily calculated from the data. An example of an integrated electrocardiogram is reproduced, and the procedure for estimation of the gradient is presented.