['The effect of preinjury beta blockade on heart rate during initial trauma resuscitation is unclear. We hypothesized that preinjury beta blockade does not affect the heart rate response to initial trauma resuscitation.', 'A case-control study of patients admitted to a level I trauma center was conducted. Medical records were reviewed for demographics, medications, injury information, and hemodynamic profiles. Logistic regression identified correlations between preinjury beta blockade and hemodynamics during initial trauma resuscitation and in-hospital mortality.', 'There were 76 deaths (cases) and 304 survivors (controls). Mean pre-resuscitation heart rate was 83 in patients on beta blocker and 89 in patients not on beta blocker (p=0.007). Mean post-resuscitation heart rate was 80 in patients on beta blocker and 85 in patients not on beta blocker (p=0.02). Tachycardia was present in 14.3% with preinjury beta blocker and 29.7% without (p=0.009). Bradycardia was present in 7.1% with preinjury beta blocker and 2.3% without (p=0.035). Of all patients who presented with an abnormal heart rate, 46% of patients on beta blocker attained a normal heart rate after resuscitation vs. 53% of patients not on beta blocker (p=not significant).'] Does preinjury beta blocker usage affect the heart rate response to initial trauma resuscitation?