AUTONOMIC REGULATION IN ASTHMATICS WITH GASTROESOPHAGEAL REFLUX

Study objective: To study the role of autonomic regulation in asthmati cs with gastroesophageal reflux (GER). Design: Prospective study. Sett ing: Autonomic function laboratory of a 908-bed university hospital. P articipants: Fifteen nonsmoking asthmatics with GER (six men, nine wom en; average age, 36 years). Interventions: Subjects were connected to an ECG monitor. BP was measured by sphygmomanometer at set intervals. After a resting period, each subject had heart rate and BP monitored d uring an 80 degrees passive tilt, Valsalva maneuver, quiet and deep br eathing, handgrip, and an echo stress test of cortical arousal. Each a utonomic function test was analyzed and defined as normal, hypervagal, hyperadrenergic, or mixed (a combination of hypervagal and hyperadren ergic responses) as compared with 23 age-matched normal control subjec ts from our laboratory (14 men, 9 women; average age, 35 years) and pu blished normal control values. Each subject had an overall response sc ore that was determined by the results of the tilt, Valsalva maneuver, and deep breathing maneuvers. Results: All asthmatics with reflux had at least one autonomic function test display a hypervagal response. O verall response scores show that eight of 15 asthmatics with GER had a n overall hypervagal response, and seven had a mixed response. Of the seven asthmatics with GER who had a mixed response score, two had a hy pervagal predominant response. Conclusions: Asthmatics with GER have e vidence of autonomic dysfunction. Heightened vagal tone may be partial ly responsible for the heightened airway responsiveness to esophageal acidification in asthmatics with reflux.