Sotalol testing unmasks altered repolarization in patients with suspected acquired long-QT-syndrome--a case-control pilot study using i.v. sotalol.

Abstract

AIMS:

The aim of this pilot study was to evaluate provocative sotalol testing to unmask abnormal repolarization due to altered myocardial electrical properties as the key feature in acquired Long-QT-Syndrome. Reliable diagnosis and risk stratification for the individual patient are complicated by the multitude of mechanisms involved in acquired QT-prolongation. The combined influence of all components determines susceptibility to arrhythmias related to QT-prolongation.

METHODS:

Twenty consecutive patients who had experienced torsades de pointes in association with QT-prolonging drugs were tested with i.v. D,L-sotalol (2mg/kg) with 24-h intensive care monitoring to evaluate the repolarization process by determining QT- and QTc-prolongations. Results were compared to age and sex matched controls.

RESULTS:

At baseline, no differences between control and study population with regard to QT and QTc were detected. After sotalol infusion, QTc increased from 422+/-17 to 450+/-22ms in controls and from 434+/-20 to 541+/-37ms in the study population. Torsades de pointes occurred in three out of 20 patients (15%) in the study population but in none of the control patients following i.v. sotalol testing.

CONCLUSIONS:

Controlled exposure to sotalol successfully identifies patients with normal QTc intervals but altered myocardial repolarization. This may be useful for clarifying diagnosis and pathogenesis of acquired Long-QT-Syndrome.

• Authors: Stefan Kääb, Martin Hinterseer, Michael Näbauer, Gerhard Steinbeck
• Journal: European heart journal (Eur Heart J) Vol. 24 Issue 7 Pg. 649-57 (Apr 2003) ISSN: 0195-668X [Print] England
• PMID: 12657223 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Adrenergic beta-Antagonists
• Sotalol

Topics

• Adrenergic beta-Antagonists
• Adult
• Aged
• Case-Control Studies
• Electrocardiography
• Female
• Humans
• Long QT Syndrome (diagnosis, physiopathology)
• Male
• Middle Aged
• Pilot Projects
• Sotalol
• Statistics, Nonparametric