Fainting & Arrhythmia

with Sanjay S. Deshpande, M.D., Cardiac Electrophysiologist, Columbia St. Mary’s

Posted: Feb. 1, 2004

Back in the Victorian era, it was considered feminine and appropriate for women to faint. The fashion, needless to say, did not apply to men, who were expected to be strong and, well, manly.

The latest word on fainting, according to Dr. Sanjay S. Deshpande of Columbia St. Mary’s, a cardiac electrophysiologist and clinical associate professor of medicine, is that manly is the best scenario for everyone.

“Our consciousness is dependent on a steady supply of blood from the heart to our brains,” he said. “So a loss of consciousness is due to a drop below a critical level in that supply.”

When someone faints, there are three possible causes:

1. Their heart rate has dropped, known as bradycardia.
2. Their heart is beating so fast it is not effectively pumping blood, called a tachycardia.
3. Blood pressure drops, irrespective of the heart rate, making it impossible to maintain blood flow to the brain, known as hypotension.

Sanjay S. Deshpande, M.D., Cardiac Electrophysiologist, Columbia St. Mary's "Fainting, in the setting of cardiac disease, is as ominous as having had a cardiac arrest from a long-term survival perspective."

The heart, a muscular, four-chambered pump driven by microvolts of electricity, has a natural pacemaker in the right upper chamber. The pacemaker regulates the heart rate, which varies depending on the level of activity. At rest, it’s slower; when activity rates rise, the heart beats faster and harder.

Arrhythmia
An arrhythmia, a disturbance in heart rate or rhythm, can cause fainting – or worse. Most of the deaths associated with a sudden heart attack are caused, not by a blockage, as is commonly thought, but by an arrhythmia.

The main difference between that and a faint is that the heart is able to quickly restart itself, averting disaster.

“Fainting is usually due to a cardiovascular problem, not a neurological problem,” he said.

It’s also not the sort of thing a doctor can figure out during a routine examination.

“An electrophysiologist is like a detective. Fainting is like a hit-and-run crime, because the person has not fainted in front of you,” he said. “So you have to put certain pieces of information together to try and solve it, because there’s a very good possibility that fainting will happen again.”

As part of the investigation, Dr. Deshpande wants to know the circumstances of the faint, and to collect eyewitness accounts of how his patient looked immediately before, during and after the incident and whether the patient has a history of cardiac disease. He then performs a physical examination and runs some tests to check for hidden cardiac disease.

The reason for the drill, he said, is that it could be a life-saver.

“Fainting, in the setting of cardiac disease, is as ominous as having had a cardiac arrest from a long-term survival perspective,” he said. “So in reality the usual cause of fainting in somebody who has cardiac disease is an arrhythmia that would have been life-threatening except it stopped on its own.”

Diagnosis
Regardless of a patient’s age and apparent circumstances, Dr. Deshpande performs the same initial evaluation. And if that doesn’t turn up a conclusive answer, he doesn’t try to guess.

“There’s too much at stake,” he said. “There are many possible causes and every one of those causes has a different treatment.”

The next step, he said, is trying to recreate the circumstances of the faint in a controlled environment. Called “provocative testing,” or a tilt-table test, it helps him make a determination in about 7 out of 10 cases. During the half-hour tilt test, patients lie on the table, which is tilted in order to keep the patient in an upright standing position without moving. If this is negative, the electrophysiology study part involves heart catheterization to test the heart’s electrical system for arrhythmias.

It used to be that patients for whom the tilt-table test didn’t yield the hoped-for result would just have to wait until the next fainting episode. Instead, now Dr. Deshpande is able to implant a small recording device beneath the patient’s skin. The small camera is like a “black box,” recording and erasing the electrodardiogram every 22 minutes. If a fainting episode occurs, the camera records and stores the event.

Whether the second fainting spell happens a year or three years from the initial episode, the returning patient – and the doctor - won’t have to go through the frustration of trying to figure out what happened. Dr. Deshpande removes the “black box,” plays the recording, and is able to make a conclusive diagnosis.

For some patients with hypotension, or low blood pressure, the solution might be as simple as increasing salt intake. For bradycardias and tachycardias, drug therapy or other catheter or device interventions, such as a pacemaker, may be recommended.

In any case, Dr. Deshpande urges people not to ignore a fainting episode, with one possible exception.

“What I would consider an ‘okay’ faint is a ‘situational faint’ such as somebody who just donated blood on a hot day and passes out. That’s a one-time occurrence in an otherwise healthy person who has no family history of fainting.”

In all other circumstances, he said, the wisest thing to do after a fainting spell is to have yourself checked by a doctor.

“It truly may be a manifestation of a serious underlying problem,” he said.

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