long Q-T syndrome

long Q-T syndrome

n.

An inherited cardiac disorder in which a defect in potassium ion channels interferes with the transmission of electrical signals to the heart muscle, producing a prolonged Q-T interval on an electrocardiogram and sometimes causing cardiac arrhythmias.

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long Q-T syndrome

Long Q-T interval syndrome Cardiology A clinical complex, most common in otherwise healthy young ♀, evoked by physical–eg, exercise or mental–eg, fright stress, resulting in episodic syncope or, if stimulus is extreme, sudden death related to ↑ autonomic tone–eg, while exercising on a hot day, accompanied by sudden onset of ventricular arrhythmia; once diagnosed, all blood relatives should have an EKG, as a prolonged Q-T interval is associated with ↑ malignant ventricular arrhythmia–eg, 'torsades de points'. See NKX2-5.