Syncope in the ED: Drop It Like It’s Hot

-Case-

A 64-year-old man presents to the ED after collapsing while walking his dog. He reports brief lightheadedness before passing out and waking up on the sidewalk a minute or two later. He denies seizure-like activity, incontinence, or confusion afterward. His vitals are normal and ECG shows sinus rhythm; labs are unremarkable. He insists he feels fine now. What next?

-Evaluation-

Syncope is a transient loss of consciousness due to temporary global cerebral hypoperfusion, characterized by rapid onset, short duration, and spontaneous recovery. It’s common in the ED and its cause can range from mild and benign to life-threatening.

Broadly, syncope can be broken into 3 major categories:

• Neurocardiogenic (or vasovagal): often triggered by pain, fear, bearing down, or standing too long; generally benign
• Orthostatic hypotension: think volume depletion, certain medications (e.g. diuretics, antihypertensives), and autonomic dysfunction
• Cardiac causes: the ones you can’t miss! Arrhythmias (brady or tachy), structural abnormalities (AS, HOCM), PE, aortic dissection, etc.

General key clues from the history:

• Syncope during exertion = red flag (think HOCM, AS)
• Sudden onset with no prodrome = worry about cardiac causes!
• Palpitations beforehand = consider arrhythmias
• Seizure-like activity, prolonged confusion = more likely a seizure
• Recurrent falls in elderly = possible orthostasis!

Workup:

• ECG: look for arrhythmias, prolonged QT, Brugada, WPW, etc.
• Fingerstick glucose crucial!
• Orthostatic vitals (though utility is debated)
• Labs: often normal, but consider CBC, troponin, BNP (if CHF suspected)
• Cardiac monitoring in ED for concerning presentations
• POCUS for cardiac function or aortic pathology in the right context
• Imaging like CT head is not routine unless focal neuro signs, trauma, or suspicion for seizure!

Risk stratification:
Several tools exist (like the Canadian Syncope Risk Score), but clinical gestalt is key! Patients with abnormal ECGs, hypotension, or concerning cardiac history need more aggressive workup or admission.

-Management-

• Treat the underlying cause if identified
• Admit high-risk patients: cardiac cause suspected, abnormal ECG, family history of sudden death, exertional syncope, severe structural disease
• Discharge low-risk patients with clear benign etiology and arrange outpatient follow-up

-Fast Facts-

• Syncope is a diagnosis of exclusion
• Cardiac syncope has the highest mortality and must be ruled out
• Not all falls are mechanical in the elderly – ask about prodromal symptoms
• Beware the “normal” ECG – some arrhythmias are intermittent
• ‘DEAD QB‘ is a helpful mnemonic of more “scary” things to keep in mind when evaluating the ECGs of syncope patients:

In the ED, your job is to rule out the dangerous and identify the benign. When it comes to syncope, it’s all about what you can’t miss!

Want to learn more? Listen to our in-depth podcast episode on this topic!

Cheers,

Tamir Zitelny, MD

-References-

1. Sandhu RK, Sheldon R. Syncope in the Emergency Department. BMJ. 2024;385:e076622. doi:10.1136/bmj-2023-076622
2. McCarthy F, Bray JE, Smith K, et al. Risk stratification of syncope patients in the emergency department: A systematic review. Acad Emerg Med. 2019;26(9):1105-1118. doi:10.1111/acem.13794
3. Costantino G, Sun BC, Barbic F, et al. Syncope clinical management in the emergency department: a consensus from the STePS group. Intern Emerg Med. 2022;17(1):1-9. doi:10.1007/s11739-021-02815-7
4. Probst MA, Gibson T, Weiss RE, et al. Risk stratification of older adults who present to the emergency department with syncope: The FAINT score. Ann Emerg Med. 2020;75(2):147-158. doi:10.1016/j.annemergmed.2019.04.020
5. Mendu ML, McAvay G, Lampert R, Stoehr J, Tinetti ME. Yield of diagnostic tests in evaluating syncopal episodes in older patients. Arch Intern Med. 2009;169(14):1299-1305. doi:10.1001/archinternmed.2009.229