2019 Volume 65 Issue 11 Pages 741-746
We report the case of a patient who had sinus arrest caused by the trigeminocardiac reflex (TCR) during mouth-opening exercises. The patient was a 37-year-old woman. Bilateral masticatory muscle tendon-aponeurosis hyperplasia was diagnosed, and bilateral coronoidectomy and aponeurectomy of the masseter muscles were performed with the patient under general anesthesia. After the start of surgery, severe bradycardia occurred during forced mouth opening and dissection of the left masseter muscle. Postoperatively, the patient engaged in mouth-opening exercises, but severe bradycardia occurred when forced mouth opening was performed. The patient was discharged 20 days after operation as she was able to maintain adequate mouth opening. She continued to experience bradycardia and temporary loss of consciousness during mouth-opening exercise, and underwent further investigation in the department of cardiovascular medicine of another university hospital. Holter electrocardiography during at-home rehabilitation therapy revealed that sinus arrest lasting ≥ 3 sec (maximum 7 sec) occurred nine times during mouth-opening exercises. Electrocardiography during these exercises also showed that sinus arrest recurred when a mouth-opening device was used. Although TCR still occurs during maximal mouth opening, by carefully continuing mouth-opening exercises the patient has successfully maintained adequate mouth opening, and her course has otherwise been uneventful.
