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QT interval heterogeneities induced through local epicardial warming/cooling. An experimental study
Antonio Guill1, Alvaro Tormos1, José Millet1
1ITACA, Universitat Politècnica de València, Valencia, Spain.
Revista Espanola De Cardiologia (English Ed.)
|November 30, 2014
Summary
Local epicardial temperature changes alter QT intervals and conduction velocity in rabbit hearts. However, these induced heterogeneities did not increase the risk of ventricular arrhythmias in this experimental model.
Area of Science:
- Cardiovascular Physiology
- Cardiac Electrophysiology
- Arrhythmogenesis Research
Background:
- Abnormal QT interval durations and dispersions are linked to ventricular arrhythmias.
- Understanding factors influencing QT intervals is crucial for arrhythmia risk assessment.
Purpose of the Study:
- To investigate the arrhythmogenic potential of inducing QT interval variations.
- To examine the effects of local epicardial cooling and warming on cardiac electrophysiology.
Main Methods:
- Isolated rabbit hearts were subjected to stepwise epicardial temperature modifications (22°C–42°C).
- Electrograms were recorded to determine QT and activation-recovery intervals.
- Conduction velocity and ventricular arrhythmia induction were assessed during programmed stimulation.
Main Results:
- Hypothermia prolonged QT and activation-recovery intervals; hyperthermia shortened them.
- Conduction velocity decreased with hypothermia and increased with hyperthermia.
- Induced heterogeneities did not correlate with the occurrence of ventricular arrhythmias.
Conclusions:
- Local epicardial temperature variations modulate QT interval, activation-recovery interval, and conduction velocity.
- Epicardial temperature-induced heterogeneities did not promote ventricular arrhythmias in this model.
Keywords:
ArrhythmiaArritmiaElectrical stimulationElectrofisiologíaElectrophysiologyEstimulación eléctricaLeft ventricleVentrículo izquierdoMore Related Videos
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