WHY DO PEOPLE FAINT?

The term for fainting due to lack of blood flow to the brain is “Syncope”. There can be other causes of fainting as well. Such as seizures or psychogenic causes.

Frequently a physician is left with a patient having “fainting spells” and the evaluation begins.

The single most important step in the evaluation is NOT testing; it is the patient history:

  • History of the fainting, including eyewitness accounts where available.
  • A detailed description of the event, warning signs, when it started, how often is it occurring, known triggers, time of day and more.

“The importance of an eyewitness account.”

“Shortly after going into private practice I was waiting to go into a movie theatre and my husband ran up to me and said someone had fainted on the sidewalk outside the theatre. I left the popcorn at the concession stand and ran out to help. I identified myself as a physician and immediately began to proceed to help the person on the pavement. She was twitching some and she was making some snoring sounds with her mouth. She was not responsive to me. She was a young girl probably in her early twenties. She was breathing but it was loud and irregular.   She had a pulse but it was very irregular and extremely fast. I immediately put my hand on the “apical impulse of her heart” and felt a very fast and very irregular heartbeat. This went on for about 15 seconds and then stopped and her heart started beating regularly and she eventually came to. This was not the first time this had happened and her physicians were evaluating her for these spells. Unfortunately as is usually the case, her physicians had never witnessed a “spell”. She declined the ambulance that was summoned when 9-1-1 was called. It was not the first time an ambulance had been called for one of her spells and after many ER visits with no results she had learned to say no to the ER. I gave the person with her my business card and told him I would be happy to talk to her physician to give my observations. I did receive a call from her physician the next week. Keep in mind this was at a time when extended event monitors and cardiac electrophysiologist were still a thing of the future for the most part. I was able to give my history and the next week she was being treated for a condition called Long QT syndrome. As of my last contact with the patient she was doing very well and had no further episodes of syncope. In her case, if the fainting was not evaluated and treated, she would remain at high risk for sudden cardiac death.”

  • The patient’s medical history including
    • Past medical history
    • Surgical history
    • Current medications both prescription and over the counter, as well as medications taken as needed
    • Medication Allergies or adverse reactions
    • Family History
    • Social History: exercise, diet, caffeine use, tobacco use, alcohol use, recreational drug use, fluid intake.

The most common causes of fainting are:

  • A temporary drop in BP leading to decrease blood flow to the brain, which leads to LOC (loss of consciousness).
  • Psychogenic
  • Seizure

Causes of a drop in BP:

  • Acute blood loss:
    • GI bleeding as with stomach ulcer
    • Extreme injury resulting in blood loss
    • Heart Rhythm Abnormality such as an abnormally fast heart beat or abnormally slow heart beat
    • Heart Structure Abnormality

“Recently a patient came to see me because she had been passing out for 4 ½ years. One of her friends had given her my name. I met this middle-aged lady and her black eye immediately stood out. This was a result of her latest syncopal episode. 2 cardiologists and a neurologist had already evaluated her several years earlier. She had an extensive work up with heart monitors because an irregular heart rhythm was expected. She even had a heart monitor implanted to record any syncopal events. She did pass out but the heart rhythm at the time of the passing out did not explain the event. Eventually the monitor was removed. She began to pass out more and more until even going to work was a challenge because her syncope was occurring so often. In her history I found she had never had an echocardiogram, which shows the structure of the heart. After examining her and hearing a heart murmur I ordered an echocardiogram. It was discovered she has a structural abnormality of the heart that was causing her syncope. It is progressive and this is why her syncope was occurring and worsening. She had surgery for the condition and she has not passed out again.”

  • Medication
  • Dehydration
  • Heavy sweating
  • Pooling of blood in the legs
  • Neurally mediated syncope (NMS), the “common” faint. Other names include vasovagal syncope, vasodepressor syncope, reflex syncope and neurocardiogenic syncope (NCS)
  • Heart failure, heart attack

When to go to the ER:

  • First ever syncopal episode
  • If injury occurs
  • If you do not return to your usual baseline soon after the spell

Events of greater concern are:

  • Those occurring with exercise
  • Those associated with palpitations or irregularities of the heart
  • Those associated with family history of recurrent syncope or sudden death
  • Those resulting in extreme injury
  • Those occurring in the elderly

Great caution must be taken in regards to driving a motor vehicle after having a syncopal episode. A physician should be consulted after the first syncopal episode. Education for those who have recurrent episodes of syncope is critical. In some situations such as passing out when having blood drawn, the evaluation may only include a history, exam and EKG. The visit should also include counseling about what to do in the future to prevent recurrences. Many cases of syncope involve totally reversible and avoidable issues such as dehydration or getting overheated or simply standing too long in one place without moving.

Even when “benign” episodes of syncope such as neurally mediated syncope occur, the recurrence of these spells has a huge impact on quality of life.

Syncope is always serious because significant injuries can occur with the episodes. I frequently will tell my patients with “benign“ causes of syncope, “I am not concerned about the reason you are passing out but I am concerned about what you hit on the way down.” Education is key for people with recurrent syncopal episodes from a “benign” cause.

This information is meant to educate but it is not intended to take the place of a physician’s evaluation and treatment. If you have not seen a physician for your syncope, call your physician or your local hospital to find a physician who can evaluate you.