We read with interest the two articles on unexplained chest pain and its potential relation to esophageal dysfunction [1, 2] and the accompanying editorial [3]. We believe that one possible cause of unexplained chest pain that may be overlooked is vocal cord dysfunction. We recently reported a case of unexplained chest pain attributed to vocal cord dysfunction [4]. The patient was a 41-year-old woman who was referred to our institution for further evaluation of "chest tightness" that presented as unstable angina. Her symptoms consisted of chest tightness, pain radiating to her neck and left arm, and shortness of breath occasionally accompanied by voice changes. An extensive cardiac evaluation showed normal echocardiographic and cardiac catheterization results. A presumptive diagnosis of asthma was made after these normal results were obtained, and the patient was treated with inhaled steroids and ß₂-agonists without success. She was subsequently referred to the National Jewish Center for Immunology and Respiratory Medicine for further evaluation.

The patient underwent a methacholine challenge test that yielded a positive result of 2.368 mg/mL; this bronchoprovocative test resulted in the recurrence of her symptom complex. Rhinolaryngoscopy done immediately thereafter showed paradoxical motion of the vocal cords with posterior chinking of the cords, a finding that is characteristic of vocal cord dysfunction. The vocal cords were visualized continually for several minutes. As the patient's symptoms resolved, her vocal cords returned to normal. She received speech training and psychosocial intervention that resolved her symptoms. The patient currently requires no further medication. To our knowledge, this is the first report of vocal cord dysfunction presenting as unstable angina.

The sensory innervation of the supraglottic larynx is caused through the internal branch of the superior laryngeal nerve, whereas the recurrent laryngeal nerve is responsible for glottic and subglottic sensations. We hypothesize that sensitization of vocal cord nociceptors could result in features of angina and vocal cord dysfunction. More information on vocal cord nociceptors is required for us to understand the pathophysiology of this disorder.