Mean arterial pressure and heart rate in the Vasopressin and Septic Shock Trial. Comparison of (a) mean arterial pressure (MAP) and (b) heart rate in the norepinephrine group (grey circles) and in the vasopressin group (black squares) of the Vasopressin and Septic Shock Trial. Values are mean ± standard deviation (SD). Heart rate was significantly lower in the vasopressin group than in the norepinephrine group over the first 4 days (P < 0.001). There were no statistically significant differences between the norepinephrine and vasopressin groups in MAP.