Table 3.

Risk factors for torsades de pointes^2,4,6

• QTc interval >500 ms • Increase in QTc interval >60 ms compared with pretreatment value • Advanced age • Female sex • Acute myocardial infarction • Heart failure with reduced ejection fraction • Hypokalemia • Hypomagnesemia • Hypocalcemia • Bradycardia • Treatment with diuretics • Concurrent administration of >1 QTc interval–prolonging drugs • Elevated plasma concentrations of QTc interval–prolonging drugs  ○ Inadequate dose adjustment of renally eliminated drug in patients with acute kidney injury or chronic kidney disease  ○ Rapid intravenous infusion of QTc interval–prolonging drug  ○ Drug interaction(s) • Possible genetic predisposition