DOES PHYSIOLOGICAL GASTROESOPHAGEAL REFLUX AFFECT HEART-RATE OR RHYTHM

An acid-induced, cholinergic esophagocardiac reflex has been observed in humans. Decrements of heart rate can be induced by direct intraesop hageal acid infusion. To ascertain whether this reflex occurs during p hysiologic reflux and whether stimulation of this reflex might precipi tate dysrhythmias, a prospective study was performed. Twenty consecuti ve patients referred for 24-h ambulatory intraesophageal pH monitoring underwent simultaneous 24-h cardiac holter monitoring. Analyses were performed only on gastroesophageal reflux episodes which resulted in e sophageal acidification to pH <4 for 60 sec or more. Evaluable cardiac holter variables included premature ventricular contractions (PVCs), premature atrial contractions (PACs), tachycardia (heart rate, >110/mi n), and bradycardia (heart rate, <50/min). Measurements were made for 60 sec before and after onset of esophageal acidification. No relation ship was noted between physiologic episodes of gastroesophageal reflux and PVCs (p = 0.29), PACs (p = 0.12), tachycardia (p = 0.33), or brad ycardia (p = 0.78). No statistically significant correlations were not ed between total 24-h acid exposure (minutes/24h) and mean heart rate (p = 0.07), number of PVCs (p = 0.41), and number of PACs (p = 0.39). Analyses of reflux episodes lasting more than 5 min with intraesophage al pH <2 also failed to show changes in pulse rate (p = 0.22). Physiol ogic gastroesophageal reflux does not induce changes in heart rate or rhythm in humans. It is possible that esophagocardiac reflexes noted d uring intraesophageal acid infusion arc related to lower pH values or to other factors such as osmolarity, temperature, or site-specific rec eptors.