Cases of Swallow Syncope Induced by the Activation of Mechanorecepters in the Lower Esophagus
A 59-year-old man was admitted to hospital for the evaluation of syncope. The patient had been in good health except for when hypertension was detected 20 years earlier, and he had subsequently been treated for 3 years. Since he was about 30 years old, he had experienced many episodes of syncope when drinking a carbonated beverage (eg., a soda pop) and beer. About 4 years ago, syncope occurred while drinking cold water when he was taking a bath. Eating sticky foods such as a sweet potato, or even fast running caused syncope. The physical examination and routine laboratory results were normal except for a slightly increased serum creatinine level (132.6 µmol/L). Electrocardiography and chest X-ray findings were not specific. The left ventricular ejection ventricular hypertrophy was detected. A brain CT was normal. A carotid massage did not evoke any abnormal rhythms. Holter monitoring showed a sinus arrest with a maximum 7.2 seconds pause while drinking beer and a carbonated beverage (). An esophagogastroscopy, performed to search for an abnormality in the esophagus and stomach, showed only superficial gastritis at the fundus. Gastric distension by air could not induce syncope or an abnormal rhythm. An esophageal manometry showed no specific esophageal motility disorder except for transient low pressure in the lower portion of the esophagus. The patient was treated with a permanent pacemaker. After backing up the permanent pacemaker, esophageal balloon inflation by a Sengstaken-Blakemore tube with the pressure of 40 mmHg at the lower esophagus induced marked sinus bradycardia (). However, no response was observed at the middle and upper esophagus.