Does physiologic 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 intraesophageal acid infusion. To ascertain whether this reflex occurs during physiologic reflux and whether stimulation of this reflex might precipitate dysrhythmias, a prospective study was performed. Twenty consecutive 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 esophageal 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/min), and bradycardia (heart rate, < 50/min). Measurements were made for 60 sec before and after onset of esophageal acidification. No relationship was noted between physiologic episodes of gastroesophageal reflux and PVCs (p = 0.29), PACs (p = 0.12), tachycardia (p = 0.33), or bradycardia (p = 0.78). No statistically significant correlations were noted 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 intraesophageal pH < 2 also failed to show changes in pulse rate (p = 0.22). Physiologic gastroesophageal reflux does not induce changes in heart rate or rhythm in humans. It is possible that esophagocardiac reflexes noted during intraesophageal acid infusion are related to lower pH values or to other factors such as osmolarity, temperature, or site-specific receptors.