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Conduction: Difference between revisions
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The QT-interval comprises the QRS-complex, the ST-segment, and the T-wave. | The QT-interval comprises the QRS-complex, the ST-segment, and the T-wave. | ||
In a (serious) prolonged QT time, is takes longer for the myocardial cells to be ready for a new cardiac cycle. There is a possibility that some cells are not yet repolarized, but that a new cardiac cycle is already initiated. These cells are at risk for uncontrolled depolarization and induce a [[ | In a (serious) prolonged QT time, is takes longer for the myocardial cells to be ready for a new cardiac cycle. There is a possibility that some cells are not yet repolarized, but that a new cardiac cycle is already initiated. These cells are at risk for uncontrolled depolarization and induce a [[Arrhythmias#Torsade_de_pointes|torsade de pointes]], a ventricular tachycardia. | ||
The QT interval is defined as follows: <cite>Lepeschkin</cite> The time between the beginning of the Q until the point where the steepest tangent line from the end of the T-wave intersects with the base line of the ECG. | The QT interval is defined as follows: <cite>Lepeschkin</cite> The time between the beginning of the Q until the point where the steepest tangent line from the end of the T-wave intersects with the base line of the ECG. | ||