Ruling out a cardiac cause
The 2017 joint guideline defined syncope as a transient loss of consciousness. “By definition, you pass out, you’re not aware of where you are, and you cannot hear,” Dr. Deal said. If a patient reports they could hear people talking, they may have lost postural tone, but they did not have syncope, she added.
“Sometimes, we see teenagers who are said to pass out and are unresponsive for 5 minutes, 10 minutes, or 20 minutes. I’m usually relieved to hear that because that gets cardiac off the hook,” Dr. Deal said. “There is nothing cardiac that makes you pass out for 20 minutes, unless people are resuscitating you.” She added, “I’m not suggesting it’s not a significant problem that you need to get to the bottom of.”
Noncardiac etiologies can be neurologic, metabolic, drug-induced, or psychogenic. “This is where the detective work comes in.”
Keep clinical suspicion high for psychogenic syncope, Dr. Deal said. Psychogenic episodes stem from significant psychological stress, often something so profoundly bothersome that they cannot cope, such as sexual abuse.
A helpful tip for diagnosing the less worrisome vasovagal syncope is asking whether a patient was sitting to standing or standing a long time before an episode, Dr. Deal said. “A common complaint is that the family went to airport, got up early, didn’t eat, and ended up standing for a long time. Kids will say they don’t feel well, they fall down, and all hell breaks loose.” Other causes of vasovagal syncope include stress, pain, or a situational trigger, for example, when a person faints during a blood draw or immunization.
The 2017 guideline also set forth the evidence behind various medications used to lower the risk of syncope. However, Dr. Deal said, “If syncope only happens every 3 years when you go to an airport, it’s probably not worth daily therapy to prevent that.”
‘The world’s most boring test’
For the most part, lifestyle measures should work to address vasovagal syncope. A tilt table test can be useful to aid the differential diagnosis, but it’s recommended only when the etiology is unclear, Dr. Deal said. On the plus side, the tilt table test allows clinicians to reproduce symptoms in a controlled environment. On the downside, she added, “It’s the world’s most boring test. It’s a challenge for the cardiologist to stay awake. It’s very boring, until all hell breaks loose.”
“I find this helpful in the setting of kids with seizures and for kids with this atypical syncope where you just cannot convince the family that these 20-minute episodes of loss of consciousness are not near-death episodes.”
Dr. Deal had no relevant financial disclosures.
*This article was updated on 10/25/2017.