The pattern of Tpeak-Tend and QT interval, and J wave during therapeutic hypothermia.

Abstract

BACKGROUND AND PURPOSE: The electrocardiogram manifestations of hypothermia

include J waves and prolongation of QT intervals. This study described changes in

repolarization patterns during therapeutic hypothermia (TH). METHODS: We measured

the QTc and the interval from the peak to the end of the T wave (TpTe) from the

V4 and V6 leads in 20 patients with TH. The TpTe was also expressed as a ratio to

the duration of QT ([TpTe/QT]x100%), and to the corrected value for heart rate

(TpTe/ radicalRR). RESULTS: The QTc became prolonged in all patients during TH.

While the TpTe/ radicalRR did not change, the ([TpTe/QTe]x100%] decreased

significantly during TH. The J wave developed during TH in seven patients. With

one patient, ventricular fibrillation occurred preceded by an abnormal J wave and

prolonged TpTe during TH. CONCLUSIONS: QTc prolongation without TpTe increase or

abnormal J wave may not be arrhythmogenic during TH.