Syncope is a sudden, transient loss of consciousness due to cerebral hypoperfusion, while pre-syncope refers to the sensation of near-fainting without actual LOC.
These conditions range from benign (vasovagal) to life-threatening (AAA rupture, PE, arrhythmia, SAH)—making accurate evaluation essential.
The chart you provided emphasizes the following priorities:
- Recognize red flags
- Perform immediate bedside tests
- Separate dangerous vs. benign causes
- Use targeted workup
- Apply appropriate emergency management
This article organizes those elements clearly for learners.
Red Flags in Syncope / Pre-Syncope
These symptoms mandate urgent evaluation:
Major Red Flags
- History of heart disease
- Chest pain, shortness of breath
- Palpitations
- Sudden syncope without prodrome
- Dark stools (possible GI bleed → anemia)
- Severe pain
- Pallor
- Focal neurologic deficit
- Toxic or environmental exposure
Immediate Bedside Actions (Step 1)
The chart highlights three immediate investigations:
✔ 1. EKG
Rules out arrhythmias, MI, conduction abnormalities.
✔ 2. Fingerstick Glucose
Detects hypoglycemia and sulfonylurea toxicity.
✔ 3. Urine Pregnancy Test (UPreg)
Essential for any female of reproductive age.
Causes of Syncope: Category Breakdown
Syncope causes from the chart are grouped into three clusters:
1. Bad & PainlessLet’s break them down.
A. BAD & PAINLESS Causes (Often Life-Threatening Without Pain)
1. Anemia (e.g., GI bleed)
Clues:
- Pallor
- Conjunctival pallor
- Dark stools (FOBT positive)
Workup:
- CBC
- Coagulation panel
- Type & Screen
Treatment:
- Identify bleeding source
- Consider transfusion
2. Cardiac Causes (Arrhythmias, Valvular Disease)
Clues:
- Sudden syncope
- Chest pain
- Palpitations
- SOB
- Murmur
- Young patient with FHx of sudden death (Brugada, WPW, long QT)
Workup:
- EKG
- Troponins
- Echocardiogram
- BMP
Treatment:
- Admit to telemetry
- Manage arrhythmia or structural disease
Cardiac syncope is a “must-not-miss” emergency.
3. Hypoglycemia
Clues:
- Diabetic patient
- Sulfonylurea use
Workup:
Serial fingersticksTreatment:
- D50 or food
- If sulfonylurea-related → octreotide + admission
B. BAD & PAINFUL Causes (Pain is a Key Clue to Severity)
These are true emergencies.
1. AAA Rupture
Clues:
- Abdominal or flank pain
- Pallor
- Elderly male
- Hypotension
Workup:
- Ultrasound
- Coags
- Type & Screen
Treatment:
Emergent surgery2. Aortic Dissection
Clues:
- Tearing chest pain radiating to back
- Unequal pulses
- Neuro deficits possible
Workup:
- CXR
- CT-A
Treatment:
- Target HR 60–70
- Target MAP 60–75
- Emergency surgery consult
3. Ectopic Pregnancy Rupture
Clues:
- Abdominal pain
- Female, reproductive age
- Vaginal bleeding
Workup:
- Urine pregnancy test
- Ultrasound
Treatment:
Emergency OB surgery4. Pulmonary Embolism (PE)
Clues:
- CP/SOB
- Sudden collapse
- Risk factors: OCPs, DVT hx, surgery, immobilization
Workup:
- D-dimer
- CT-A
Treatment:
- Anticoagulation
- Thrombolysis if unstable
5. Subarachnoid Hemorrhage (SAH)
Clues:
- Sudden syncope
- “Worst headache”
- No trauma
Workup:
- CT head
- LP if needed
Treatment:
Neurosurgery consultSAH can present as secondary syncope.
C. OTHER Causes (More Common, Usually Less Dangerous)
1. Orthostatic Hypotension
Clues:
- Dry, dehydrated
- Orthostatic drop in BP
Workup:
Rule out anemiaTreatment:
Hydration2. Seizure
Clues:
- Incontinence
- Tongue lacerations
- Post-ictal confusion
- Known seizure disorder
Workup:
- BMP
- CT head
- LP if infection suspected
Treatment:
- Treat underlying cause
- Neurology consultation
3. Vasovagal Syncope
Clues:
- Classic prodrome: nausea, warmth, tunnel vision
- Triggered by pain, fear, standing
- Benign exam
Workup:
Diagnosis of exclusionTreatment:
- Reassurance
- Hydration
Pearls & Pitfalls (from the chart)
✔ Young patients with syncope
Beware:
- Wolff-Parkinson-White
- Brugada syndrome
- Long QT
- Family history of sudden death
✔ Elderly
Low threshold to admit for cardiac workup.
✔ Important reminders
- Cardiac syncope is the most lethal.
- Stroke/TIA are VERY rare causes of syncope.
- Add CPK if prolonged downtime → rule out rhabdomyolysis.
- Consider that “syncope” may actually be a seizure or arrhythmia.
Documentation Essentials
Well-structured documentation is key.
General
- History of CAD/MI
- Presence of CP/SOB/palpitations
- GI symptoms (dark stool, abdominal pain)
- Prodrome or sudden onset
HEENT
- Conjunctival pallor
- Signs of head trauma
- Tongue lacerations (seizure clue)
Abdominal
- Soft, non-distended
- No pulsatile mass
Rectal
- Brown stool
- FOBT result
Neuro
- Focal exam
- Return to baseline mental status
Quick Comparison Table
| Category | Disease | Key Clues | Workup | Treatment |
|---|---|---|---|---|
| Bad & Painless | Anemia | Pallor, dark stool | CBC, T&S | Transfusion |
| Cardiac | Sudden CP/SOB | EKG, echo | Admit | |
| Hypoglycemia | Diabetic | FSBG | D50 + octreotide | |
| Bad & Painful | AAA Rupture | Abdominal pain | US | Surgery |
| Aortic dissection | Tearing pain | CT-A | HR/MAP control | |
| Ectopic rupture | Abd pain, +UPreg | US | OB surgery | |
| PE | Sudden SOB | D-dimer, CT-A | Anticoagulation | |
| SAH | Worst HA | CT/LP | Neuro consult | |
| Other | Orthostatic | Dehydrated | Orthostatics | Hydrate |
| Seizure | Post-ictal | CT/BMP | Treat cause | |
| Vasovagal | Prodrome | Exclusion | Reassure |
FAQs About Syncope & Pre-Syncope
1. What is the most dangerous cause of syncope?
Cardiac arrhythmia or aortic dissection.
2. Does syncope always require imaging?
No—only if trauma, abnormal neuro exam, or concern for SAH.
3. How is PE-related syncope identified?
Sudden collapse + chest pain/SOB + risk factors.
4. Is seizure a type of syncope?
No—seizure is a separate neurologic event but often confused with syncope.
Related Articles
- Basics of Emergency Medicine – Initial Assessment & Approach
- Headache – Causes, Diagnosis & Treatment
- Head Injury – Emergency Diagnosis & Management
- Eye Complaints – Emergency Diagnosis & Management
- Altered Mental Status (AMS) – Evaluation & Management
- Intoxication – Emergency Evaluation & Management
- Dizziness & Lightheadedness – Causes, Diagnosis & Treatment
- Sore Throat – Causes, Centor Criteria & Treatment
- Cough – Causes, Diagnosis & Treatment
- Shortness of Breath – Causes, Diagnosis & Emergency Approach
- Asthma – Emergency Management, Diagnosis & Treatment
- Chest Pain – Causes, Diagnosis & Emergency Evaluation
- Vomiting – Causes, Diagnosis & Management
- Abdominal Pain – Upper, Lower, Flank & Diffuse Causes
- Fever – Causes, Evaluation & Emergency Management
- Back Pain – Red Flags, Evaluation & Management
- Ankle & Foot Injuries – Assessment & Emergency Management
- Rash – Dangerous Causes, Diagnosis & Treatment
- Syncope & Pre-Syncope – Causes, Diagnosis & Management
- Laceration – Evaluation, Repair & Wound Care
- Leg Pain – Causes, Assessment, DVT & Trauma
- Vaginal Bleeding – Pregnancy, Miscarriage & Ectopic Causes
- Weakness – Focal vs Generalized Causes & Evaluation
