Why Is He Fainting?

Mysterious fainting spells signal a deadly emergency for a middle-aged man.

By Tony DajerNov 16, 2006 6:00 AM


Sign up for our email newsletter for the latest science news

"Tell the patient he needs to return to the hospital. Right away."

"Why? He says he feels fine."

"Tell him there's something wrong with his heart," I said. "He has to come back."

Eight hours earlier, at 2 a.m., the patient had come to the emergency room. One of my favorite residents had presented the details of the case.

"Forty-eight-year-old Asian man, passed out watching television," she related in her precise Indian-British diction. "Felt a fullness in the head. The family says they saw him shake, turn blue, and come to a few minutes later. No medical history, really, except that he smokes one pack a day."

"He was watching TV? Doing nothing else?" I asked, dubious.

She was ready for me. "Yes. On his bed at home. I asked him twice."

No one just passes out in bed.

Fainting, known to doctors as syncope (SIN-kuh-pee), is what happens when a disruption occurs in the blood flow to the brain. In bipeds like us, the brain depends on a finely tuned vascular system. To adjust heart rate and blood pressure to changes in posture, the body employs two competing nervous systems, the sympathetic and the parasympathetic. The sympathetic is like the body's internal espresso machine: revving things up using adrenaline and the fight-or-flight reflex. The parasympathetic slows things down, delivering signals via the long, winding vagus (Latin for "wandering") nerve that runs from the base of the brain down through the esophagus and into the gut.

In young people, fainting rarely signals disease. If the right noxious stimulus—like the sight of blood—comes along, the sympathetic network might abruptly bump up the heart rate. To reestablish calm, the vagus nerve starts firing. Sometimes, especially if you are standing still, the body's calming response can prompt a faint, also known as vasovagal syncope. If this patient had fainted at rest, I needed to know if an unsettling event had somehow triggered too much of a parasympathetic response, causing vasovagal syncope. So I went to see the patient.

Via the translator, I asked, "Were you having a fight at home? Anything upset you?"

"No," came the reply.

"Have you been getting enough sleep? Are you working too hard?"


"And you were feeling perfectly well until you fainted?"

The translator went back and forth a few times with the whole family. "He says he felt his heart beating fast, then felt dizzy just before he fainted."

That would be the initial bump in heart rate that provokes the vagus to respond. Something was upsetting this man.

"Where do you work?"

"Clothing factory."

"Any problems today?"

A much longer exchange followed. "He says he did something very bad at work today. His boss yelled at him."

Bingo, the smoking gun. The resident looked impressed.

"It's all in the history," I said.

We checked the electrocardiogram. "Looks like a right bundle," she said, pointing out a pattern.

In a normal EKG, each spike is followed closely by a valley, reflecting electrical discharge across the heart. A right bundle branch block is when the spike and valley are accompanied by another, wider spike that indicates sluggish electrical conduction through the right ventricle.

"Normal variant," I assured her.

"What about this S-T segment?" she asked, pointing her finger at the line coming off the last spike. Instead of dropping down, it stayed up like a billowing sail.

"I don't know," I answered, "but you see funny things sometimes. Rule number one: In vasovagal syncope, history rules. Discharge him."

After the shift, one of our cardiologists called to tell me that he had reviewed the previous day's EKGs, and my patient's stood out. "Was he admitted?"

"No, why?" My own heartbeat surged.

"It's a Brugada's."

"Huh?" A long-ago lecture flashed through my head. The speaker had shown the slide of an EKG, saying, "This is Brugada syndrome. I have to tell you about it, but you'll never see it."

"There is a risk of sudden death," said the cardiologist.

I grabbed an article from my files. The patient's EKG was the spitting image of a patient with Brugada.

In the Philippines they call it bangungut, meaning "to rise and moan in sleep." In Thailand it is lai tai; in Japan, pokkuri; in the United States, sudden unexpected nocturnal death syndrome, or (this being the land of acronyms) SUNDS. In the 1940s, doctors had puzzled over a bizarre syndrome in Southeast Asia that woke healthy young men (and very few women) from sleep with night terrors, then killed them. At the end of the Vietnam War, with the refugee exodus from the area, case reports in the United States began to filter in. At first, many doctors speculated that it was a type of extreme stress reaction.

In 1992, the doctor brothers Josep and Pedro Brugada contradicted that notion in a paper on eight European patients who had suffered unexplained fainting spells. While being monitored in the hospital, all eight came within seconds of death. Their heart monitors recorded normal heartbeats suddenly degenerating into ventricular fibrillation, the chaotic rhythm that wipes out the heart's pumping action. Happily, all were resuscitated. Nothing in the patients' history matched other known causes of sudden cardiac death. The signature of the mystery syndrome was a distinctive shared EKG pattern: the spike-valley-spike of a right bundle branch block, with the final segment billowing out abnormally as my patient's did.

Brugada syndrome is mercifully rare. In Japan, under 1 percent of the population has the EKG pattern; in the United States, less than half a percent does. Of those with only the EKG findings, most will never have a problem. However, anyone who has fainted for no reason, or has relatives who died young, might be at risk for sudden death. Among the eight patients in the Brugadas' study, two had a relative who had died without warning.

In 1998 the hereditary defect was traced to a gene that codes for a protein component of sodium channels in heart cells. The job of a heart cell is to contract, like a miniature muscle, and to pass an electrical impulse to its neighbor. In response to the electrical impulse, doughnut-shaped proteins embedded in the neighboring cell membrane open, and charged ions like sodium move in and out of the cell, propagating the charge. In Brugada syndrome, the sodium ions enter too slowly because the channel is defective. The defect is most pronounced in cells on the surface of the heart, which is reflected by a puffed-out S-T segment on an EKG. No one knows why these problems don't emerge until the patients are over 30.

Something similar goes wrong in a typical heart attack. Most deaths from heart attacks stem from ventricular fibrillation caused by electric eddies and short circuits—in other words, disordered conduction. Prompt treatment with one of the new automated external defibrillators works very well because the electric charge reboots the heart and brings its contractions back into sync.

In a normal person who faints from a vagal overload, the sympathetic network kicks back in, and all is well. But in a person with Brugada, nighttime vagal activity can generate uneven electrical conduction in the heart. The result is fainting from chaotic, ineffectual heart rhythms like ventricular tachycardia, or even death from full-blown fibrillation.

After admitting the patient, the next question was whether to go straight for an implantable defibrillator—the only effective treatment—or insert a catheter into his heart and electrically test the likelihood of fibrillation.

The debate ended that night. At 1 a.m. the patient's monitor showed multiple runs of ventricular tachycardia, the near-chaotic rhythm that often precedes fibrillation. Without protest, he agreed to be transferred uptown for that defibrillator.

The next day the resident had that "have I got a follow-up for you" look.

"I heard," I said with a grin. "Rule number two: Beware of old docs who think they know all the rules."

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!


Already a subscriber?

Register or Log In

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Our List

Sign up for our weekly science updates.

To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2023 Kalmbach Media Co.