Background Oesophageal sensory stimuli alter neurocardiac function through autonomic reflexes. Aim To evaluate in patients with idiopathic supraventricular cardiac dysrhythmias and gastro-oesophageal reflux disease (GERD) whether GE reflux alters neurocardiac function and the effect of acid suppression on cardiac symptoms. Methods Thirty-two patients (13 females and 19 males; age: 20–69 years) with dysrhythmias plus GERD, and nine patients (five females and four males; age: 43–58 years) with GERD only, underwent simultaneous 24-h pH-metry and ECG monitoring. Power spectrum analysis of heart rate variability (PSHRV) was obtained with both its low frequency (LF, sympathetic modulation) and high frequency (HF, vagal modulation) components. Hourly mean oesophageal pH and LF/HF ratio were correlated. A 3 months fulldosage PPI therapy (esomeprazole 40 mg/day) was prescribed. Results In 18 (56%) of the 32 patients with dysrhythmia and in none with GERD only, a significant (P