Acute effects of norepinephrine infusion on electrocardiographic parameters: A prospective study focusing on the...

Norepinephrine is widely used as a first-line vasopressor in acute hypotension and septic shock. Its acute effects on electrocardiographic (ECG) parameters, particularly the frontal QRS-T angle, remain unclear.

To evaluate the short-term impact of therapeutic-dose norepinephrine infusion on ECG parameters, with a focus on the frontal QRS-T angle, in the emergency department.

This prospective observational study included 135 adult patients clinically indicated for norepinephrine in the emergency department of a tertiary training and research hospital. ECG recordings were obtained at baseline and at the first and second hours after norepinephrine initiation. Parameters assessed included heart rate, P-wave duration, PR interval, QRS duration, QT, QTcB, P axis, QRS axis, T axis, and frontal QRS-T angle. Temporal changes were analyzed using the Friedman test.

The median age of the patients was 77 (68-84) years, and 52% were male. When ECG parameters were compared over time, no statistically significant change was detected in any parameter, including heart rate, P-wave duration, PR interval, QRS duration, QT, QTcB, and frontal QRS-T angle (p > 0.05 for all). The frontal QRS-T angle was recorded as 91° (31-159) at baseline, 86° (28.5-152) at the first hour, and 76° (30-150) at the second hour (p = 0.273). Similarly, no significant change in ECG parameters was observed in the sepsis subgroup.

Short-term therapeutic-dose norepinephrine infusion in the emergency department did not significantly affect ECG parameters, including the frontal QRS-T angle. These findings suggest that norepinephrine does not acutely alter ventricular repolarization heterogeneity.