To compare orthostatic changes in heart rate (HR), systolic and diastolic blood pressure (SBP, DBP) in athletes with acute sport-related concussion (SRC) vs. control athletes.

Evidence suggests SRC is associated with autonomic nervous system (ANS) dysfunction and symptom generation. There is limited data on how to evaluate ANS function following SRC.  This study investigated the use of orthostatic vital signs (VS) as a potential surrogate of ANS dysfunction following SRC.

Cohort study comparing 133 athletes (45.9% female) with acute SRC (<30 days post-injury) to 100 control athletes (54.0% female). Participants completed a single standard orthostatic VS evaluation including HR, SBP, and DBP in the supine position as well as immediately and 2-minutes after standing.  Linear regression compared supine-to-standing changes in HR, SBP, and DBP as a continuous variable (ΔHR, ΔSBP, ΔDBP) between groups and logistic regression compared patients with positive orthostatic VS changes (sustained HR increase ≥30 beats per minute (bpm), SBP decrease ≥20 mmHg, DBP decrease ≥10 mmHg at 2 minutes) between groups, accounting for age and sex. 

Significant between-group differences were present for delayed ΔHR (18.4±12.7 bpm vs. 13.2±11.0 bpm in SRC vs. control groups; p=0.002) and ΔSBP (-3.1±6.6 mmHg vs. -0.4±6.5 mmHg in SRC vs. control groups; p=0.001), with positive orthostatic HR changes present more frequently in SRC patients (18.0% vs. 7.0%; p=0.027). Odds of positive orthostatic HR findings were greatest in adolescents (13-17 years old; OR=2.79).