Medical Mystery: Sandwich-Induced Fainting

When British physician Dr. Russell Cherry saw a 26-year-old woman at his office in January, he expected the visit to be a routine consultation. But that was before he found out that sandwiches were making her pass out.

The woman complained that she had been experiencing intermittent and unexplained blackouts for the last 10 years. The episodes had sent her to the hospital twice.

An extensive battery of medical tests had revealed nothing out of the ordinary. But Cherry said the fact that her fainting spells appeared to be associated with certain foods offered a tantalizing clue to her condition.

"She made it very clear to me that when she had food she felt funny almost every time, and she had been feeling this way for many years," he said. "I could tell that it was something organic; it sounded real. I could tell that it was not something that she was making up."

Cherry, with the assistance of Dr. Christopher Boos, a cardiologist at University Hospital Birmingham in the United Kingdom, learned that the woman had a rare condition known as swallow syncope, in which her heart would temporarily stop because of a nerve reaction triggered by the swallowing.

Sandwiches and carbonated beverages were the primary culprits in her unusual condition. While for most people the biggest threat posed by these foods would be the possibility of heartburn, for this patient the stakes were much higher.

The last time she passed out, she was eating a sandwich while driving. Moreover, her condition also caused her to avoid eating in general. With the woman standing at nearly 5 feet, 4 inches and weighing little more than 102 pounds, doctors initially suspected that she suffered from an eating disorder, although subsequent tests revealed that this was not the case.

"The patient was becoming increasingly frustrated and was desperate to get to the bottom of these potentially disabling symptoms," Boos said.

The Sandwich Test

Because certain foods appeared to trigger her episodes, the doctors asked the patient to go home and return with some sandwiches. The test that followed rivaled any seen on medical mystery dramas.

"We offered her a sandwich," Boos wrote in the study. Upon eating the sandwich, the woman experienced yet another episode. And while this one did not cause her to lose consciousness, it did cause her heart to pause for two seconds.

The simple test helped confirm the condition that eluded blood screenings, hormone tests and chest radiography.

"It was actually a relief to both us and the patient, as it meant that there might be potential solution to this problem," Boos said.

Dr. Douglas Zipes, professor of cardiology at the Indiana University School of Medicine and editor in chief of the journal HeartRhythm, said that while the condition is exceedingly uncommon, it is not unheard of.

"There are a number of reports in the literature going back many years," he said, adding that syncope has also been associated with other actions, such as urination (micturition syncope) and coughing (cough syncope, which doctors casually term "cough drops").

"I had a similar case several years ago, treated with a pacemaker with no big deal," Zipes said.

Such was the treatment for the woman, who received a pacemaker in February. According to the case report, she has not fainted since the procedure. And unlike before, she can now enjoy whatever she pleases for lunch.

"When last seen, in June 2008, she could eat sandwiches with impunity," Boos wrote in the report.

An Underdiagnosed Problem?

While this patient's story has a fortunate ending, Boos noted that the rare condition may seem even more rare because the condition is never properly identified in many of those who experience it.

"The true incidence is unknown, but it is very uncommon, perhaps less than one in 10,000, as the condition is underdiagnosed," he said.

But Zipes said that anyone who experiences "lightheaded spells with coughing, swallowing [or] urinating" should see a doctor for a complete evaluation.