Case

Hi, I’m calling from the ER and sorry to bother you on a weekend. I have this 14-year old female who has been previously healthy and passed out while she was running in her first high-school cross-country race this morning. When she came in by paramedics who were at the race, she looked a bit pale and sweaty but she did just run the race. I gave her some fluids and she seems to be feeling better. Her vital signs are stable but her heart rate was a bit up at 95 bpm when she first came in. I’m thinking about sending her home after her fluids are up but I’m sure you heard about that young kid in the town over that died while running track a few months ago. They say it was related to his heart so I just wanted to make sure I checked with you before sending her home. Anything else I should do?

What am I thinking?

I am continually amazed by what young people are capable of when they put they make up their minds and push their bodies beyond natural limits. Of all the physical activities that we encounter in young people, cross country running seems to result in frequent episodes of syncope during competitive meets. The concept of syncope during physical activity is concerning and rightfully so as a harbinger of serious cardiac disease. However, history taking often finds that the athlete syncope patient may not be passing out in midactivity, but often postactivity when the dedicated and driven young-person crosses that finish line. In the eternal struggle of mind over the body, the mind often wins the battle but the body eventually and inevitably wins the war.

History and physical

As has been mentioned previously in this book, a thorough and detailed history is paramount to the clinical evaluation of patients suffering syncope. In many ways, it can be compared to a crime scene investigation in which details are gathered from all eyewitnesses to put together a reenactment of the event in question. Given the importance of such history-taking, it is imperative that the appropriate time be taken (and allotted) for such an evaluation. Part of the evaluation often involves asking questions repeatedly to get a clear answer as patients and parents will often report the main event skipping over multiple details that can help tease out the differential diagnosis.

First, an understanding of the circumstances of the event can be helpful. Was this a typical day or a special event (i.e., sports practice, race day, etc.)? Where was everyone located and who witnessed the event? What was the environmental climate during the event (i.e., hot day outside vs. indoors)? Excessive heat combined with strenuous physical activity can lead to heatstroke. What was the general feeling of the patient before the event: history of previous illness? Appropriate nutrition and hydration that day and days prior? Overall feeling of health?

A critical question to ask is to enquire when the event took place. Did this occur while participating in physical activity or was it afterward? In the case of a runner, was it during the actual run or minutes afterward in recovery? It is not uncommon for complaints of “syncope with exercise” to reach the pediatric cardiologist only to determine through a more detailed history that the event occurred after the race while drinking water. It is also not uncommon to hear stories of coaches or relatives encouraging young athletes to keep walking despite the feeling of dizziness and lightheadedness that eventually results in collapse.

Next, focus on the details of the event. What was the patient feeling and how were they acting according to eyewitnesses, minutes to seconds before the event? Those who experience a vagal-related syncope often experience symptoms of lightheadedness, dizziness, and/or tunnel-vision without mention of unusual heartbeats or chest pain. How did the patient collapse: were they able to put their hands out to “catch” their fall or did they collapse without doing so, leading to injuries? Patients who were able to catch themselves as they fell usually have scratches and bruises on their extremities. How did the patient look when they were passed out? Usually, young people who have undergone a neurocardiogenic event during physical activity appear quite pale.

Next, focus on recovery. How long after the initial event did it take for the patient to regain consciousness? Was there a true loss of consciousness or loss of vision/hearing? Did anyone feel for a pulse or initiate resuscitative efforts? In the case of the neurocardiogenic athlete, the loss of consciousness is quite brief with the almost immediate regaining of consciousness once blood flow has been restored to the brain—usually seconds after the head falls to the ground. Ask the young athlete how they felt for the rest of the day? The neurocardiogenic syncope victim is often quite exhausted from their “fight or flight” adrenaline response.

Family history is also important to rule out a genetically inherited disease. Questions should include any family member that suffered an unexplained death such as an unexplained car accident or drowning. Questions should be asked about family members with unexplained seizures or deaths while playing sports-either in practice or in game. Ask about deaths presumed to be due to heart attack before the age of 50 years, which may be in fact a sign of arrhythmic death.

In the adolescent, a proper social history can be lifesaving. This should involve interviewing the adolescent with parents or family out of the room and a chaperone present. Always ensure confidentiality with the patient making sure to let them know that the only event in which confidentiality may be broken is if you felt their life was in danger. Ask politely for their honesty and reassure that the questions asked are related to their health and for no additional purposes. Discuss home life, school life, and relationships. Review medication use, both prescribed and not prescribed as well as drugs of abuse. Victims of physical or sexual abuse may present with feigned syncope as a way of seeking help. Take the opportunity to ask about the potential for harm to themselves or others and ensure their feeling of safety at home. Ask if there is anything else the patient would like to share or ask while their family is out of the room. Finally, thank the adolescent for their honesty and express that they can always reach out if they have additional concerns.

Physical examination is often normal without evidence of cardiac disease manifesting as a pathologic murmur or rhythm change on auscultation. In the patient with a recent neurocardiogenic event (within hours), the patient may appear pale and fatigued. Abnormal body temperature is concerning for heatstroke. There may be bruises or scratches on the hands, forearms, or knees secondary to an attempt to catch themselves while falling.

Diagnostic testing

With a benign medical history and a story consistent with VVS or neurocardiogenic syncope, there are no specific tests that would be required except possibly an electrocardiogram. Often an electrocardiogram is ordered to rule out any obvious potential arrhythmic conditions. Patients are often seen in emergency rooms or urgent cares and it is not unusual to see an elevated specific gravity on urinalysis suggesting dehydration. There may be some slight electrolyte changes on serum chemistry panel as well.

Action plan

With the appropriate medical history details and normal physical, most patients who suffer syncope around the time of exercise and not during exercise are likely experiencing a form of neurocardiogenic syncope. If an ECG is performed it is most likely to present as normal. The primary method of treatment for neurocardiogenic syncope is to encourage hydration and intake of salt. The daily recommended amount of noncaffeinated beverages is 64 oz per day at baseline. With the addition of physical activities and loss by perspiration, this could mean additional ounces of fluid. This often requires a conscious effort to drink this amount of fluid. Urine should appear clear or straw colored but never dark yellow. Adding salt to the diet in the form of pickles, pretzels, or table salt to food will help. For those who tolerate it, salt tablets can be taken to help supplement and can be helpful for athletic competition. Although various pharmacological agents have been described (e.g., midodrine, fludrocortisone), water and salt alone are often enough to treat neurocardiogenic syncope. Exercise has also been shown to be helpful for these patients. Patients may return to activity and are encouraged to maintain adequate nutrition and hydration. Other possible factors that promote neurocardiogenic syncope are hypoglycemia (enquire if they missed a meal and were very hungry when they passed out), lack of sleep, concurrent illness (especially with fever or vomiting), and significant physical pain (abdominal colic, menstrual cramps, migraines, etc). For more difficult or recurrent cases, a pediatric cardiology evaluation may be indicated.