Diltiazem therapy for symptoms associated with nutcracker esophagus. A randomized double-blind, cross-over prospective trial in 22 patients was designed to evaluate possible effect of an oral calcium channel blocker, diltiazem, on symptoms of chest pain and/or dysphagia in patients with nutcracker esophagus. We studied 22 consecutive patients referred to an esophageal diagnostic center for evaluation of noncardiac chest pain or dysphagia having high amplitude esophageal contractions, 14 of whom completed the study. Diltiazem (60-90 mg qid) was compared with placebo, each being administered for 8 wk. Patients were evaluated with esophageal motility pre- and posttreatment periods and with regular symptom assessment throughout each 8-wk treatment. Active diltiazem therapy resulted in significantly lower (p less than 0.05) mean distal esophageal peristaltic pressure (128 +/- 20 mm Hg; +/- SE) than placebo (158 +/- 16 mm Hg). Mean chest pains scores were significantly (p less than 0.05) lower with diltiazem therapy than with placebo. Only nine of the 14 patients fulfilled presently acceptable criteria for diagnosing nutcracker esophagus, and the diltiazem effect was similar, although not significant, because of the smaller sample. Conclusions: In this preliminary study involving 14 patients, the oral calcium channel blocker, diltiazem, appeared to improve noncardiac chest pain associated with strong esophageal contraction, the nutcracker esophagus. These improved symptoms were associated with significant decreases in contraction pressure. 