Severe nonexertional (resting) chest pain may bedue to myocardial ischemia, esophageal dysfunction,psychiatric disorder, or any combination thereof andfrequently poses a difficult diagnostic challenge. Our aim was to investigate causes of chest painin patients with coronary artery disease. Forty-fivepatients with angiographically proven obstructivecoronary lesions and recurrent chest pain at rest were studied; 18 had refractory pain despite cardiactherapy (problem group), and 27 had documentedmyocardial ischemia (control group). Esophagealmanometry, edrophonium provocation, 24-hr pH studies,and psychiatric interview were performed in all patients. Theclinical evolution and the outcome of specific treatmentduring follow-up was used to establish the etiology ofchest pain. Esophageal dysfunction was identified in all problem patients and in 52% of controls,and the esophagus was incriminated as the source of painin 8 (44%) and 5 (18.5%), respectively. After a meanfollow-up of 49 months (range 24-76 months), the cause of chest pain in the problem groupwas identified as panic disorder in 9 patients (50%),gastroesophageal reflux in 6 (33%), esophagealdysmotility in 2 (11%), and gallstone disease in 1 (6%). Of the control patients, 18 (67%) had ischemicpain alone, while 9 had concurrent causes: panicdisorder in 5 (19%) and esophageal dysfunction in 4(15%). Esophageal dysfunction and psychiatricdisturbances are common in patients with coronary arterydisease presenting with resting chest pain, and maycontribute to patients' symptoms.