Cortisone and QTc-Interval

Scientific and clinical data report about shortening of QTc-interval in patients treated with cortisone. Peal et al. analyzed chemical suppression of long QT syndrome (Type 2) in an in vivo zebrafish model. Their study revealed that flurandrenolide reproducibly suppressed the long QT phenotype via the glucocorticoid signaling pathway. In contrast to treatment with dexamethasone and testosterone, treatment with pure mineralocorticoid deoxycorticosterone acetate did not suppress long QT phenotype. Knockdown of the glucocorticoid receptor or, conversely, of the androgen receptor showed that flurandrenolide acting through the glucocorticoid receptor shortens ventricular action potentials. The mechanism is distinct from trafficking rescue of the defective zebrafish-ERG channel. The authors discuss that a drug normalizing repolarization would be a novel therapeutic tool in long QT syndrome and conclude that glucocorticoids could be expected to aid in the acute management of patients with long QT syndrome, e.g. in episodes of arrhythmic storm. In addition, corticoid induced normalization of the QT interval is reported in a patient with drug-induced prolongation of the QTc interval. Brostoff et al. report on a patient suffering from mucocutaneous leishmaniasis treated with sodium stibogluconate. During therapy, the QTc interval prolonged and returned to normal within 4 days after starting glucocorticoid therapy with prednisolone 20 mg twice daily. Interrogation of the study: * shortens cortisone the QTc-interval? * how long is the interval until shortening of QTc-interval? * is the effect prolonged? * is the effect dose dependend?