Table 2.

Calculation of risk score for QTc interval prolongation

Risk factors points	Points
Age ≥ 68 years	1
Female sex	1
Loop diuretic	1
Serum K+ ≤ 3.5 mEq/L	2
Admission QTc ≥ 450 ms	2
Acute myocardial infarction	2
≥ 2 QTc-prolonging drugs	3
Sepsis	3
Heart failure	3
One QTc-prolonging drug	3
Maximum risk score	21

A score of ≤ 6 predicts low risk, 7–10 medium risk, and ≥ 11 high risk of drug-associated QT prolongation. Modified from Tisdale et al [9]. in Circ Cardiovasc Qual Outcomes. 2013;6(4):479–487