Yee Guan Yap & A. John Camm 
Acquired Long QT Syndrome 

In recent years there has been considerable interest in the
diagnosis and understanding of ventricular repolarisation,
particularly the QT interval prolongation and abnormal T and T/U
wave morphology associated with torsades de pointes. Advances in
ion channel cloning have greatly improved our understanding of the
role of ionic channels in mediating cardiac repolarisation.
Unfortunately, it is increasingly recognised that a number of
drugs, both those associated with altering repolarisation, and
others for non-cardiac conditions can increase the propensity for
polymorphic ventricular tachycardia, syncope and even ventricular
fibrillation and sudden death.

In this volume, arrhythmia specialists from St. George’s
Hospital Medical School, London discuss the mechanisms behind QT
prolongation and torsades de pointes. They focus particularly on
the risk of individual cardiac and non-cardiac drugs in provoking
long QT syndrome, providing a comprehensive review which will be
useful for all electrophysiologists treating polymorphic
ventricular tachycardias, and will expose important regulatory
issues for pharmaceutical authorities and for the wider medical
community.

Table of Content

Preface vi

1 Introduction 1

2 Mechanisms of acquired QT prolongation and torsades de pointes 8

3 Measurement of the QT interval and repolarization assessment 24

4 Introduction to drug-induced long QT syndrome 60

5 Risk of QT prolongation and torsades de pointes with antiarrhythmic drugs 69

6 Risk of QT prolongation and torsades de pointes with antihistamines 87

7 Risk of QT prolongation and torsades de pointes with psychotropic drugs 102

8 Risk of QT prolongation and torsades de pointes with antimicrobial and antimalarial drugs 121

9 Risk of QT prolongation and torsades de pointes with prokinetics and miscellaneous other drugs 140

10 Acquired long QT syndrome secondary to cardiac conditions 163

11 Acquired long QT syndrome secondary to noncardiac conditions 171

12 Perspective on drug-induced repolarization changes 182

Index 191

About the author

A. John Camm, MD, FRCP, FESC, FACC

Professor of Clinical Cardiology and Head, Department of
Cardiological Sciences, St. George’s Hospital Medical School,
London

Marek Malik, Ph D, MD, DSc, FACC, FECS

Professor of Cardiac Electrophysiology, Department of Cardiological
Sciences, St. George’s Hospital Medical School, London

Yee Guan Yap, BMed Sci, MBBS, MRCP

British Heart Foundation Research Fellow in Cardiology, Department
of Cardiological Sciences, St. George’s Hospital Medical
School, London