situational syncope is a sudden and brief loss of consciousness , which can occur after urination , defecation , swallowing , or coughing.1 ) swallow syncope is a rare type of situational syncope caused by a hypersensitive vagotonic reflex in response to deglutition.2 ) this type of syncope may be induced by ingesting solid foods or cold beverages , independent of underlying esophageal or cardiac disease . in this report , we describe a case of a patient who did not have cardiac disorders and experienced swallow syncope induced by a cold beverage provocation test . a 39-year - old man was referred to the department of cardiology to evaluate recurrent syncope . the patient had the first syncopal episode during meals 5 months ago . at that time , he experienced dizziness and chest tightness , which was followed by a sudden loss of consciousness . subsequently , he has experienced four more episodes of syncope . he had a 2-year history of hypertension , which was treated with telmisartan , amlodipine , and carvedilol . additionally , he was diagnosed with diabetes mellitus 1 week before he visited our hospital . his blood pressure was 118/72 mm hg , and his heart rate was 70 beats per minute . he was alert , and the results of other physical examinations including a cardiac examination were normal . the results of most of the hematological and biochemical tests were normal , but the hemoglobin a1c level was 8.2% . an initial 12-lead electrocardiogram ( ecg ) and 24 hours ecg recording both showed a normal sinus rhythm . a treadmill exercise test showed that the patient had good exercise capacity , and no abnormal findings were obtained . subsequently , we performed the head - up tilt test . during this test , we made him drink a cold beverage ( chilsung cider ) . the patient felt sudden dizziness , and his ecg showed a transient complete atrioventricular ( av ) block with no ventricular escape beats for 6.2 seconds ( fig . 1 ) . the head - up tilt test was repeated the next day . during that test , the patient was given a cold beverage at 5 , 15 , and 16 minutes from the start of the test and immediately developed a complete av block without ventricular escape beats at time points of 4.92 , 5.2 , and 5.56 seconds . the patient was diagnosed with swallow syncope and was advised to avoid cold beverages , particularly cold carbonated drinks . after he was discharged , the patient did not suffer from any dizziness or syncope . however , if syncope recurs after controlling cold beverage intake , a permanent pacemaker will be implanted . syncope is defined as the transient loss of consciousness due to transient global cerebral hypoperfusion . the characteristics of syncope are rapid onset , short duration , and spontaneous complete recovery . syncope is a common clinical symptom and is divided into cardiovascular syncope , neurally mediated syncope , and syncope due to orthostatic hypotension . neurally mediated syncope ( also called neurocardiogenic syncope ) is the most common type of syncope , whereas swallow syncope is a rare type of neurally mediated syncope.3 ) since spens described a possible case of swallow syncope in 1793,4 ) approximately 60 similar cases have been reported.2 ) swallow syncope is associated with various conditions , including esophageal disorders , such as esophageal stricture , esophageal diverticulum , esophageal spasm , esophageal cancer , achalasia , and hiatal hernia,5 - 7 ) as well as cardiac diseases , including myocardial infarction , heart failure , and atrial fibrillation.8)9 ) in contrast , palmer10 ) reported cases of swallow syncope without involvement of esophageal or cardiac diseases . the vasovagal reflex between the heart and esophagus plays an important role in the occurrence of syncope . the afferent impulses from esophageal receptors reach the nucleus tractus solitaries in the brain stem . efferent signals from this tract reach an adjacent motor nucleus that gives rise to the efferent nerves of the parasympathetic system , which lead to the heart . these vagal fibers primarily innervate the sinoatrial ( sa ) node , atrial musculature , and av node , which generates various bradyarrhythmias.2)11 ) av block is the most common cause of swallow syncope . however , sinus bradycardia , sa block , and complete atrial and ventricular asystole have also been reported to cause swallow syncope.12 ) many kinds of foods such as cold beverages , alcoholic drinks , and solid food cause swallow syncope . therefore , carefully obtaining a patient history plays a critical role recognizing the relationship between the intake of foods and the occurrence of syncopal episodes . because swallow syncope is often combined with other disorders , it is important to evaluate the esophageal and cardiac structures of patients with swallow syncope . additionally , echocardiography may be helpful for evaluating cardiac abnormalities in such cases.12 ) in this case , we used a head - up tilt test to continuously monitor the patient 's cardiac rhythm and blood pressure using a finometer device ( ohmeda monitoring systems , englewood , co , usa ) , while provoking swallow syncope associated with ingestion of a cold beverage . a symptomatic transient complete av block was reproducibly induced at an early phase of the head - up tilt test whenever the patient drank a cold beverage . we did not perform a head - up tilt test without cold beverage provocation , because his syncopal episodes were always associated with swallowing cold beverages . we think that consuming a cold beverage played a major role in this patient 's syncopal episodes . therefore , orthostatic stress might not have contributed to the occurrence of his syncopal episodes . it is necessary to assess the factors that trigger and aggravate syncope before treatment , so the patient can avoid heart blocking medications such as digitalis , beta - blockers , and calcium antagonists . if the symptoms are related to ingesting specific beverages or foods , syncope could be prevented by avoiding them.2 ) swallow syncope can be treated using anticholinergic agents , but the effects are not necessarily reliable , and the side effects may be intolerable . surgical treatment , such as denervation of portions of the esophagus , might be effective in some cases . permanent pacemaker implantation is also effective in patients with recurrent syncope.13 ) in this report , we have confirmed the association between ingestion of a cold carbonated beverage and the occurrence of syncopal symptoms . since the patient started avoiding the consumption of cold beverages , he has not experienced loss of consciousness or shown other relevant symptoms . if syncopal episodes recur , permanent pacemaker implantation will be required .
swallow syncope ( also known as deglutition syncope ) is a relatively rare type of syncope that is treatable if diagnosed correctly . 
 we report a case of a 39-year - old man with recurrent swallow syncope . 
 the patient did not have structural heart disease . 
 he developed a complete atrioventricular block upon drinking a cold beverage ( chilsung cider ) while undergoing a repeated head - up tilt test . 
 the patient was advised to avoid cold beverages and has been symptom free for 5 months .