A prolonged QT interval has a variety of causes and can be a very serious ECG finding, as it may lead to the potentially fatal arrhythmia polymorphic ventricular tachycardia (Torsades de Pointes).

Department of Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA Correspondence to Dr M J Ackerman, Long QT Syndrome ... 31 As such, the ECG must be examined ...

Long QT syndrome (LQTS) is the prototypic cardiac channelopathy underscored by profound genetic and phenotypic heterogeneity. In 1991, the first LQTS chromosome locus was identified and ...

Atrioventricular (AV) dissociation occurs in complete heart block (third-degree AV block) and ventricular tachycardia ... of the PP interval. A prolonged QT interval from hypocalcemia has a ...