Provider Response to QTc Prolongation on Standard 12-Lead EKG: Do We Notice or Do We Care?

Drugs and electrolyte imbalances are widely recognized as common triggers of a prolonged QT interval. We conducted a chart review to assess provider response to prolonged QT reported on a standard 12-lead electrocardiogram (EKG).

We identified all Veterans Affairs Pittsburgh Healthcare System patients in a 6-month period with an EKG reporting a corrected QT (QTc) >500 ms. We excluded confounding or uninterpretable EKGs. Charts were reviewed to assess medications and electrolytes at the time of the EKG as well as the setting (inpatient vs outpatient) in which the EKG was obtained. Provider documentation of QTc and any corrective measures were sought.

After exclusions, 106 patients were included in this analysis (87 [82%] inpatient and 19 [18%] outpatient). Most were male (101, 95%) with a mean age of 63.5 ± 10.6 years. At the time of index EKG, most patients were receiving at least one (72, 68%), and frequently two or more (35, 33%), QTc prolonging medications. Providers documented QTc prolongation in 20 inpatients (19%). Drugs were adjusted or discontinued in only two inpatients (2%). There were 14 patients (14%) with potassium level <3.6 mmol/L and 10 of 69 (14%) patients had a magnesium level <1.7 mg/dL.

Patients with prolonged QTc on EKG were more likely to be inpatients than outpatients. Inpatients were more likely to be receiving multiple types and classes of QTc prolonging medications. In the vast majority of cases, providers did not address the prolonged QTc and only rarely initiated remedial actions.