[Electrocardiographic changes in electrolyte inbalance. Part 2: Alterations in serum calcium (author's transl)].

74 patients (hypocalcemia: 41 patients, hypercalcemia 13 patients, 20 patients as control) without heart disease were examined. A prolongation of the relative QT-interval was found in 90% and a flat or inverted T-wave in 25% of the patients with hypocalcemia. In 77% of the patients with hypercalcemia the QT-interval was shortened. A good, clinically useful correlation between the QT-interval and the serumcalcium-concentration could be established in patients with hypo- and hyper-calcemia.