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QT Interval Calculator

QTc = QT / √(RR)

Torsades Risk Assessment

ECG Parameters

Correction Formula

Example Cases

Common QT‑prolonging Drugs

DrugClassRisk
AmiodaroneAntiarrhythmicHigh
HaloperidolAntipsychoticModerate
AzithromycinMacrolideModerate
CitalopramSSRIDose‑dependent
OndansetronAntiemeticModerate

QTc Risk Categories

Normal<440 (M) / <470 (F)
Borderline440‑470 (M) / 470‑480 (F)
Prolonged>470 (M) / >480 (F)