QTc prolongation
Pronunciation: Q-T-C
An abnormal lengthening of the corrected QT interval on electrocardiogram, increasing risk of dangerous heart rhythm abnormalities.
Full Definition
QTc prolongation refers to an abnormal extension of the corrected QT interval on an electrocardiogram (ECG), which measures the time between the start of the Q wave and the end of the T wave, corrected for heart rate. This condition is particularly relevant in psychopharmacology because many psychiatric medications, including antipsychotics, tricyclic antidepressants, and lithium, can cause QTc prolongation. Prolonged QTc intervals increase the risk of torsades de pointes, a potentially fatal ventricular arrhythmia. Regular ECG monitoring is recommended when prescribing medications known to affect cardiac conduction, especially in patients with additional risk factors.
Usage
Usage note: QTc should be written with capital letters; 'c' denotes 'corrected.'
In Context
- "Baseline ECG showed QTc prolongation, requiring careful medication selection." — pretreatment cardiac assessment
- "The antipsychotic was discontinued due to significant QTc prolongation on follow-up ECG." — medication safety monitoring