The authors examine the behaviour of electric systole during nisoldipine treatment using doses of at least 10 mg/die in association with modifications of ischemic signs recorded using surface ECG in a series of 70 elderly patients. Patients were subdivided into three groups according to the results obtained from a comparison of real electric systole (QT) with that corrected for ventricular frequency (Qtc), as well as the difference expressed in mean values (VM). 1) Patients with elongated QT. Following nisoldipine treatment this group showed a mean elongation of electric systole of 0.393" +/- 0.025 with a R correlation index between electric systoles before and after treatment of 0.633" which expresses the amplitude of the elongation for each starting QT unit (p < 0.001). The mean value in the two conditions increased from -1.381 +/- 2.111 contraction units to 3.568 +/- 2.697 elongation units and mean deviation was 4.886 +/- 2.170 units with an absolute value of 211.0 units which expresses the elongation of the electric systole in the overall sample compared to calcium antagonists as an iatrogenic phenomenon. Ischemic signs improved or disappeared in 40 out of 44 cases (90.91%) for the T wave and in 36 out of 41 cases (87.80%) for the ST tract. 2) Patients with normalised QT. In 6 cases which showed elongated pretreatment electric systole, it was observed that values became normal passing from a mean of 0.390" +/- 0.40 to 0.377" +/- 0.053. Mean deviation diminished from 3.833 +/- 0.983 units to 1.333 +/- 1.211 units with statistical significance only for paired data in 2 groups (p < 0.001), without correlation.(ABSTRACT TRUNCATED AT 250 WORDS)