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Updated: Jun 19, 2026

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
Published on: January 16, 2019
Familial inducible torsade de pointes with normal QT interval
Abstract:
A familial presentation of torsade de pointes is described. The propositus had recurrent syncope, documented torsade de pointes, a normal Q-T, and close coupled premature ventricular beats initiating the paroxysmal arrhythmia. The mother had sporadic syncope without documented torsade de pointes, a normal Q-T, and closely coupled premature ventricular beats. Electrophysiological studies demonstrated reproducible inducible torsade de pointes tachycardia in both patients. Serial drug testing in both revealed suppression of induced torsade de pointes with oral propranolol. Chronic oral propranolol resulted in clinical cure in both patients.
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