CARDIOESOPHAGEAL REFLEX - A MECHANISM FOR LINKED ANGINA IN PATIENTS WITH ANGIOGRAPHICALLY PROVEN CORONARY-ARTERY DISEASE

Objectives. The purpose of this study was to investigate the presence of a cardioesophageal reflex in patients with coronary artery disease that may explain the mechanism of ''linked angina.'' Background. It ha s been previously shown that esophageal acid stimulation can reduce co ronary blood flow in patients with syndrome X, suggesting the presence of a cardioesophageal reflex in humans. Methods. We studied the effec t of esophageal acid stimulation on coronary blood flow in 14 patients with angiographically documented significant coronary artery disease and in 18 heart transplant recipients, Hydrochloric acid (0.1 mol/lite r) and 0.9% saline solution were infused in random, double-blind manne r (60 ml over 5 min) through a fine-bore tube positioned in the patien t's distal esophagus, and coronary blood how measurements were obtaine d after each infusion by use of a 3.6F intracoronary Doppler catheter positioned in the proximal left anterior descending coronary artery. R esults. Coronary blood how was reduced significantly by esophageal aci d stimulation in the coronary artery disease group (before acid 70.4 /- 14.3 ml/min, after acid stimulation 46.4 +/- 19.1 ml/min [mean +/- SD], p < 0.01), However, there was no significant difference in corona ry blood flow during saline infusion (73.5 +/- 15.3 vs, 72.5 +/- 14 ml /min), Coronary blood flow in the heart transplant group was not affec ted by acid or saline infusion. Conclusions. Esophageal acid stimulati on can cause anginal attacks and significantly reduce coronary blood f low in patients with coronary artery disease, The lack of any signific ant effect in heart transplant recipients with heart denervation sugge sts a neural reflex.