Neural reflex arcs from the esophagus and heart have been shown in both animals and man. The purpose of this study was to further investigate these pathways in individuals undergoing cardiac catheterization. A total of 298 patients undergoing cardiac catheterization were asked to participate in the protocol. Thirty patients were able to complete the study. Esophageal manometry and pH were monitored throughout the cardiac procedure. Afterwards, esophageal provocation with ice water, hydrochloric acid, and balloon inflation was performed with observation of cardiac rate and rhythm. Twelve patients with normal coronary arteries developed diffuse esophageal spasm on either esophageal or cardiac provocation. In one patient with abnormal coronary arteries, coronary angioplasty precipitated diffuse esophageal spasm. Esophageal acid sensitivity was increased in patients with normal coronaries as compared to those that were abnormal. The esophageal pain threshold was significantly lower in patients undergoing angioplasty versus those undergoing coronary angiography alone. There was no significant change in esophageal pH during invasive cardiac maneuvers and manipulations. In conclusion, cardiac manipulation can induce esophageal motility abnormalities, but not gastroesophageal reflux. Coronary angioplasty is associated with esophageal hyperalgesia.