QT Prolongation After Minor Head Trauma in a Pediatric Patient.

We report a case of QTc prolongation associated with mild concussion in a pediatric patient. An 11-year-old male presented to the emergency department after sustaining a head injury during football practice. He complained of headache and blurry vision. Physical examination was within normal apart from an irregular heart rhythm. Electrocardiogram (ECG) showed normal sinus rhythm with QTc (Bazett formula) 460 ms. The patient was diagnosed with concussion and referred for cardiology follow-up of the QTc. ECG the next day showed QTc 462 ms (heart rate 105 bpm) supine and 494 ms after suddenly standing up (heart rate 120 bpm). Family history was negative for sudden cardiac events. Exercise stress testing 1 week later showed a baseline QTc 462 ms and 488 ms at 4 min into recovery. Holter monitoring showed evidence of increased parasympathetic activity manifested by marked sinus arrhythmia. Repeated ECG, exercise stress testing, and Holter monitoring 3 months later showed normalized QTc values. His concussion symptoms were resolved at the time of repeat testing. Mild head trauma/concussion could be associated with prolonged QTc and abnormal cardiac repolarization. While these changes seem to be self-limiting, they remain a possible substrate for malignant arrhythmias. Recognition of these changes would lead to appropriate reassurance and/or precautions in the acute setting, especially in at-risk populations such as long QT syndrome patients.