Key Questions for Syncope Evaluation
A thorough clinical history is the cornerstone of syncope evaluation and should include specific questions about circumstances before, during, and after the event, as this can determine the cause in up to 50% of cases. 1, 2
Initial Diagnostic Questions
Confirming True Syncope
- Was loss of consciousness complete?
- Was it transient with rapid onset and short duration?
- Did the patient recover spontaneously and completely without sequelae?
- Did the patient lose postural tone? 1, 2
Circumstances Before the Attack
- Position: Was the patient supine, sitting, or standing?
- Activity: Was the patient at rest, changing posture, during/after exercise, during/after urination, defecation, coughing, or swallowing?
- Predisposing factors: Was the patient in a crowded/warm place, standing for prolonged periods, or in a post-prandial state?
- Precipitating events: Was there fear, intense pain, or neck movements? 1, 2
Onset of the Attack
- Were there prodromal symptoms like nausea, vomiting, abdominal discomfort, feeling cold, sweating, aura, neck/shoulder pain, blurred vision, or dizziness?
- Did the patient experience palpitations before losing consciousness? (suggests arrhythmic cause)
- Was there absence of prodrome? (consistent with cardiac arrhythmia) 1, 2
During the Attack (Eyewitness Account)
- How did the patient fall? (slumping or kneeling over)
- What was the skin color? (pallor, cyanosis, flushing)
- What was the duration of loss of consciousness?
- What was the breathing pattern? (snoring)
- Were there movements? (tonic, clonic, tonic-clonic, minimal myoclonus, automatism)
- How long did the movements last? 1, 2
End of the Attack
- Did the patient experience nausea, vomiting, sweating, feeling cold, confusion, or muscle aches?
- Was there injury, chest pain, palpitations, or urinary/fecal incontinence?
- Was there post-episode fatigue or weakness? (typical of neurocardiogenic syncope) 1, 2
Medical Background Questions
Cardiac History
- Is there a history of myocardial infarction or left ventricular dysfunction?
- Does the patient have repaired congenital heart disease?
- Is there known structural heart disease? 1, 2
Family History
- Is there a family history of sudden cardiac death?
- Are there congenital arrhythmogenic heart diseases in the family?
- Is there a family history of fainting? 1, 2
Medication History
- Has the patient recently started new medications, especially antiarrhythmics or antihypertensives?
- Is the patient taking phenothiazines or tricyclic drugs (especially in elderly)?
- What over-the-counter medications or supplements is the patient taking? 1, 2
Other Medical History
- Neurological history (Parkinsonism, epilepsy, narcolepsy)
- Metabolic disorders (diabetes)
- History of head trauma 1
Risk Stratification Questions
High-Risk Features (Suggesting Cardiac Etiology)
- Age >45 years
- Abnormal ECG
- History of cardiovascular disease
- Reduced ventricular function
- Brief or absent prodrome
- Syncope during exertion
- Syncope in supine position
- Family history of inheritable conditions or premature sudden cardiac death 1, 2
Practical Pitfalls to Avoid
- Don't dismiss cardiac causes when initial ECG is normal (intermittent arrhythmias may require extended monitoring)
- Don't rule out orthostatic hypotension with a single negative test (delayed orthostatic hypotension may take >3 minutes to develop)
- Don't focus on neurological causes before excluding cardiac etiologies (cardiac causes are more life-threatening)
- Don't order unnecessary laboratory tests without specific clinical indications 2
By systematically addressing these questions, clinicians can effectively diagnose the cause of syncope in most patients and determine appropriate management strategies to reduce morbidity and mortality.