You said that the swallowing triggers a vagal reflex? What is the vagus nerve?
The vagus nerve is a nerve that generally slows the heart beat, reduces blood pressure and, in general, opposes the sympathetic nerves, the characteristic "fight or flight" reaction [aka stress response]. The vagus is important in the GI [gastrointestinal] tract to increase motility [movement]. Ordinarily, when you swallow a message is sent to the brain, [which then sends] a swallowing message to the esophagus saying to increase esophageal motility. For some reason, this message from the brain is also going to the heart and telling it to slow. And why that cross wiring happens, I don't know.
What is happening in the heart when it receives this slowing message from the brain?
The electrical signal doesn't make it [from the heart's top chambers] to the bottom [ones]; it's called heart block…. Heart block occurs because the vagus sends its impulse to the AV node [the atrioventricular node, a specialized section of tissue that relays electrical signals through the heart], causing it to block conduction from the top chamber to the bottom chambers. … Or, the vagal impulse can stop the normal pacemaker in the heart called the sinus node.
Why would this reflex be triggered by certain foods and not others?
It may take greater distension [expansion] of the esophagus [to stimulate the response, which may occur] with bulk food rather than liquids.
How common is the condition? Do women get it more than men?
It's uncommon but not unheard of. There have been many isolated reports. … It can [also] occur with coughing—it is probably a similarly induced vagal mechanism. … It's so infrequent that I don't know if there is a preference [for women or men].
For several years, doctors could not get the correct diagnosis for this woman. How do you explain that?
All you need to do is to record an electrocardiogram while she's swallowing and you'll get the answer. [Referring to the electrocardiogram results published in The Lancet, Zipes pointed to a large gap between spikes on the top line of the diagram. This gap indicates a pause in the heartbeat lasting 2.129 seconds. The line below represents the woman's heart rhythm after cardiologists gave her an artificial pacemaker to maintain a steady beat].
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7 Comments
Add CommentI can't wait for this condition to appear on an episode of 'House'.
Reply | Report Abuse | Link to thisHouse would need to combine swallow syncope with the mercury story earlier!
Reply | Report Abuse | Link to thisSo that thing about Mama Cass choking on a ham sandwich...True!
Reply | Report Abuse | Link to thisNo kidding! I'd like to see what different diagnoses they come up with before House makes them feel silly for not realizing it's a swallow syncope!
Reply | Report Abuse | Link to thisAnd they said smoking causes heart attacks. LMAO!!! Anything apparently CAN!
Reply | Report Abuse | Link to thisI am surprised no one has mentioned the Bush pretzel incident:
Reply | Report Abuse | Link to thishttp://edition.cnn.com/2002/ALLPOLITICS/01/13/bush.fainting/
For the sake of possibly helping someone else, here is a brief story of my own experience with swallow syncope.
Reply | Report Abuse | Link to thisI have had the condition for about 20 years and it was never diagnosed until recently. Actually I diagnosed it myself in frustration that doctors did not recognize it. I had many eating situations ending up in syncope (fainting). A neurologist accurately felt it was a vaso vagal response. I had a barium swallow and all looked well. So, I just felt it was something I had to live with. Up until 10 years ago I fainted many times while eating scaring everyone around me. I got to the point where I could tell when it was going to happen and if I got some water to swallow quickly I could prevent it. Then on Dec. 17, 2011 I was home alone, reading in my husband's comfortable chair. I had a bit to eat while sitting there and did not have water handy. However, I did not get that feeling of being about to faint. I noticed something was not right, everything became very quiet, like the clock stopped ticking in the room. I felt my life force draining out through my feet and worried that my husband would come home and find me dead in his chair. I couldn't remember breathing so I took several big breaths and then tried to get out of the chair. I am a very strong woman, but I could not get up. Finally on the 3rd try I did get up but my legs were folded and barely working. By this time I was nauseated and, clinging to furniture I made my way into the kitchen where I vomited violently several times. I had no idea what was happening--a stroke, food poisoning? I was hungry for dinner that night and slept well. The next night I was awake all night figuring it out. In the morning I researched on the computer and figured out that I had experienced a total AV block. After seeing my family doctor I was referred to a cardiologist, who was not familar with swallow syncope (it is quite rare). She put me on a heart monitor. Within 3 days, while eating a sandwich my heart paused for 8 seconds. We figured that on 12/17/2011 my heart paused for 15-30 seconds with maybe a few flutters in between. I almost experienced 'sudden death'. On January 27 I had a pacemaker implanted. I then had an endoscopy and my throat is normal, a little narrow near the stomach, but normal. I still have swallowing problems, but the pacemaker seems to ensure that my heart will not pause (stop) again from this vaso vagal response. I think this condition is more common than what is suspected. My endoscopist said Mama Cass died from this.