BACKGROUND Congenital long QT syndrome (LQTS) is characterized by QT prolongation. However, the QT interval itself is insufficient for diagnosis, unless the corrected QT interval is repeatedly ≥500 ms without an acquired explanation. Further, the majority of LQTS patients have a corrected QT interval below this threshold, and a significant minority has normal resting corrected QT interval value...

Various QT interval variables and heart rate variability parameters were studied in six patients with ventricular fibrillation but without heart disease and compared with findings in 21 normal persons. QT and QT dispersion (QTd) were measured from conventional 12 lead ECGs: for dynamic QT analysis, QT intervals were automatically measured to the end of the T wave (QTe) on a 24 h ECG recording. ...

AIM To reassess QT interval rate correction. BACKGROUND The QT interval is strongly and inversely related to heart rate. To compare QT intervals between different subjects with different heart rates requires the application of a QT interval rate correction formula. To date these formulae have inappropriately assumed a fixed relation between QT interval and heart rate. An alternative method of...

Twelve consecutive patients who developed torsade de pointes (polymorphous ventricular tachycardia with marked QT prolongation, TdP) over a 4 year period were treated with intravenous injections of magnesium sulfate. In nine of the patients a single bolus of 2 g completely abolished the TdP within 1 to 5 min, and in three others complete abolition of the TdP was achieved after a second bolus wa...

sudden, unexpected death may occur in apparently healthy individuals. its occurrence in psychiatric patients has raised the concern that the use of psychotropics, especially antipsychotics, may be associated with an increased risk of sudden death. this concern is maintained even though not all psychiatric patients who have succumbed to sudden death have been on psychotropics. early reports pres...

implanted due to continued risk of arrhythmia from electrolyte loss from the ileostomy. The QTc came down to 454ms and BNP fell to 179pg/ml at discharge. QT prolongation is the surface ECG manifestation of abnormal repolarisation of myocardial cells due to problems with cellular ion channels. The disorder is classified as either congenital or acquired. Acquired QT prolongation may be due to: 1....

BACKGROUND The present study examined pacing site-dependent changes in QT interval and transmural dispersion of repolarization (TDR) and their potential role in the development of torsade de pointes (TdP). METHODS AND RESULTS In humans, the QT interval, JT interval, and TDR were measured in 29 patients with heart failure during right ventricular endocardial pacing (RVEndoP), biventricular pac...

Introduction: QT dispersion assesses repolarization inhomogeneity on 12-lead standard ECG. However, the implications of the electrical cardiac vector during the repolarization phase (the T wave loop) with the genesis of this phenomenon are unknown. Methods and Results: The aim of this study was to explore conventional 12-lead resting ECG QT dispersion and the corresponding morphology of the spa...