Initial Evaluation

This is a guide through the initial evaluation of patients with syncope. The syncope workup in the emergency department can be hard due to the fact that most patients present to the emergency department without symptoms. 

The program to the right is an interactive flowchart for the initial evaluation, risk management and treatment of patients with suspected syncope in the emergency setting. The flowchart is based on the comprehensive information below. Start by clicking on the “start” button.


Recognition/risk stratification of causes for transient loss of consciousness (T-LOC). In particular causes of T-LOC with a high risk for acute cardiac death or causes such as a first epileptic convulsion. 


Transient loss of consciousness

An acute apparent loss of consciousness with a duration of less than 5 minutes, with loss of postural control, and a spontaneous and complete recovery of consciousness.


T-LOC caused by cerebral hypoperfusion, due to systemic hypotension.

Flowchart 1

Initial Evaluation

Three questions are of interest:

  1. Is the patient ABC (airway, breathing, circulation) at presentation?
  2. Is the patient suffering from T-LOC?
    1. Was the patient unconscious?
      1. Amnesia during unconsciousness
      2. No respons to speech or touch during the unconsciousness
      3. Loss of motor control (falls, myoclonic jerks, lying still, incontinence)
    2. Quick onset and short duration of the unconsciousness
  3. Is there an obvious cause and/or is there a high risk of acute cardiac death
For T-LOC, the most important diagnostic tool is the medical history
Start history taking with open questions
What happened? What did you feel? How did you do afterwards?

Historical Clues

Highlighted in RED are risk factors for cardiac syncope

Highlighted in BLUE are risk factors for epilepsy

Circumstances prior to T-LOC

  • Posture: supine, sitting, standing

  • Activity: during exercise, after exercise, after standing up

  • Specific circumstances: micturition, defecation, coughing, swallowing, the sight of blood, (veni)puncture, fear

  • Predisposing factors: hot environment, fasting

  • Specific and rare triggers: a sounding alarm clockdivinglight flashes

Start of T-LOC

  • Pallor, sweating, abdominal discomfort, vomiting

  • Palpitations: regular or irregular? Fast or slow? (beware: young people can indicate a sinus tachycardia as “palpitations”, although this is innocent)
  • Absence of: pallor, nausea, sweating during multiple episodes of T-LOC
  • Epileptic aura, focal attack

During T-LOC (eye-witness)

  • Duration of T-LOC

  • Eyes during unconsciousness: open (syncope, epilepsy) or closed (psychogenic)
  • Snoring (syncope: during unconsciousness; epilepsy: during recovery)
  •  Cyanosis (risk for both cardiac syncope and epilepsy!)
  •  Total number of myoclonic jerks (syncope: <10; epilepsy: >20)
  • Lateral tongue bite

During the end of T-LOC

  • Pallor, sweating, nausea, abdominal discomfort, vomiting

  • Incontinence of urine or defecation
  • Prolonged confusion (i.e. dysfunctional imprinting; sleeping is not confusion) 
  • Myalgia
  • Rapid spontaneous and complete recovery

Medical background and history

  • History of cardiac disease

  • Familial acute death < 40 years old with an unknown cause

  • Many episodes of T-LOC/long duration of T-LOC (psychogenic)
  • Medication (anti-diabetic drugs, anti-hypertensive drugs, psychiatric medication), intoxications

Useful information of anamnesis

  • Palpitations, fever, loss of blood, dyspnea on exertion


Physical Examination: general physical examination

Points of interest:

  • Auscultation of the heart: are indications for structural heart disease present or an arrhythmia present?
  • Supine and standing blood pressure and pulse: After 5 minutes of supine rest the blood pressure and pulse must be measured at least twice. The patient then rises from supine to standing position. Within 3 minutes of standing the blood pressure and pulse must be measured again. One speaks of orthostatic hypotension if the systolic blood pressure drops with at least 20 mmHg, or the diastolic blood pressure drops with at least 10 mmHg within 3 minutes. If the blood pressure dropped it is wise to continue measuring while standing to see if it will drop further. One must also ask the patient if he/she experiences symptoms during standing.
  • Neurological examination: in particular attention for the lateral tongue bite
  • Trauma (capitis) due to a fall during T-LOC

ECG: pay particular attention to:

  • Bifascicular block
  • Intraventricular conduction delay (QRS > 0.12 sec)
  • Mobitz Type 1 second-degree AV block (Wenckebach)
  • Asymptomatic sinusbradycardia (< 50/min), Sino-arterial exit block or sinus pause > 3 sec in absence of negative chronotropic drugs
  • Non-sustained VT
  • Pre-excited QRS-complex (normal: QTc male 300-450 ms; female 300-460 ms)
  • Long or short QT-interval
  • Early repolarization
  • RBBB pattern with ST-elevation in V1-V3 (Brugada syndrome)
  • Negative T waves in right precordial leads, epsilon wave and late ventricular potentials are suggestive for Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)
  • ST-elevations and Q’s are suggestive for myocardial infarction

Laboratory only when indicated: 

Hb, electrolytes (sodium, potassium, calcium, magnesium), glucose, troponine, creatine kinase, pro – BNP, d – dimer, arterial blood gas analysis

Risk stratification

If no cause if found using the information provided above, one must determine whether the risk of a cardiovascular event or death is high.
Patients with T-LOC with the following characteristics have an increased risk for a cardiovascular event or death, and must be hospitalized or extensively evaluated.

  • Structural heart disease and coronary artery disease
  • Clinical signs that are suggestive for cardiac syncope
    • Syncope during exercise or while in supine position
    • Specific triggers, like a sounding alarm, or diving
    • Absence of prodromal symptoms (during multiple episodes of T-LOC)
    • Palpitations prior to syncope
    • Familial history of acute cardiac death or cardiac disease
  • ECG characteristics mentioned earlier

Flowchart 2


The policy is determined by the cause of the T-LOC, with the risk of acute cardiac death or the magnitude of the risk for the patients’ health.

  • Category RED (cardiac cause and first convulsion): Acute hospitalization and (rhythm) observation (cardiac) or imaging of the brain (convulsion)

  • Category ORANGE (orthostatic hypotension, very frequent reflex syncope, psychogenic pseudosyncope): policlinical evaluation preferably in a syncope unit

  • Category GREEN (isolated reflex syncope, recognized epilepsy): explain and potentially follow-up by GP or attending physician