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Syncope
Syncope is a brief loss of consciousness from reduced blood flow to the brain, with full, spontaneous recovery; the aim of the work-up is to find the dangerous cardiac syncope, which is revealed mainly by the history, examination, standing blood pressure and the ECG.
Why it matters in the exam
Questions ask you to classify the faint into one of three types: reflex (vasovagal after prolonged standing, pain or fear, or situational — on micturition, coughing or swallowing), orthostatic hypotension (a fall of 20 mmHg or more systolic or 10 or more diastolic within 3 minutes of standing), and cardiac — an arrhythmia or structural disease such as aortic stenosis or hypertrophic cardiomyopathy. Syncope on exertion, when lying down, or after palpitations raises suspicion of a cardiac cause.
Tests that are not needed in a routine work-up — head CT, EEG and carotid Doppler — are also asked, versus what does help: an echo when structural disease is suspected, prolonged rhythm monitoring (Holter or an implantable loop recorder) for recurrent unexplained faints, tilt testing, and carotid sinus massage over the age of 40. Treatment: explanation and counter-pressure manoeuvres for reflex syncope, stopping blood-pressure-lowering drugs for orthostatic hypotension, and treating the cause in cardiac syncope.
Another exam point is telling syncope from a seizure: lateral tongue biting, prolonged confusion afterwards and muscle pain point to a seizure, while brief jerks can occur in syncope too.
Key points
- Three types: reflex, orthostatic and cardiac.
- The basics: history, examination, standing blood pressure and ECG.
- High-risk features: exertion, lying down, palpitations, heart disease, family sudden death, abnormal ECG.
- Orthostatic: a fall of 20/10 mmHg within 3 minutes of standing.
- No routine head CT or EEG; echo and rhythm monitoring according to suspicion.
Summary table
| Type | Clues | Confirming test | Treatment |
|---|---|---|---|
| Reflex (vasovagal, situational) | Prolonged standing, heat, pain, fear, micturition or coughing; sweating and nausea beforehand | History; tilt test in unclear cases | Explanation, counter-pressure manoeuvres, fluids and salt |
| Orthostatic hypotension | Standing up quickly, antihypertensives, dehydration, autonomic neuropathy | Fall of 20/10 mmHg within 3 minutes of standing | Stop drugs, fluids, midodrine or fludrocortisone |
| Arrhythmia | Syncope lying down or on exertion, palpitations, abnormal ECG | Holter, implantable loop recorder, electrophysiology study | Pacemaker, ICD or ablation according to the cause |
| Structural disease | Exertional syncope, murmur, chest pain | Echocardiogram | Treat the cause (e.g. valve replacement) |
| Carotid sinus hypersensitivity | Age over 40, head turning, a tight collar | Massage: pause longer than 3 seconds or systolic fall of more than 50 | Pacemaker in the cardioinhibitory form |
Free exam questions
בן 71 , ברקע squamous cell carcinoma of the neck. פנה בשל אירוע של SYNCOPE בזמן גילוח , ללא נפילה או חבלת ראש . במיון יציב , אירועים דומים בעבר , פעם בזמן נהיגה ועוד פעם במהלך שחייה . עבר בירור קרדיאלי מקיף כולל אקו לב , הולטר אק " ג וצנתור לבבי , שהיו תקינים . מתמצא , בדיקה נוירולוגית תקינה , אק " ג סינוס , סדיר . מה מהבאים מסביר את מנגנון הסינקופה בחולה ? (the question as examined, in Hebrew)
- א. VASOVAGAL SYNCOPE
- ב. REFLEX MEDIATED SYNCOPE
- ג. ACUTE DYSRYTHMIA
- ד. SITUATIONAL SYNCOPE
בן 87, כחלק מבירור אירוע של עילפון (syncope) נבדק ל"ד בעת שינוי תנוחה: ל"ד בשכיבה 150/90, דופק 70 לדקה סדיר; ל"ד בעמידה כעבור 3 דקות 100/80, דופק 90 סדיר. איזו אבחנה נוספת יכולה להיות למטופל זה? (the question as examined, in Hebrew)
- א. Amyloidosis
- ב. טיפול תרופתי ב- prednisone
- ג. מצב לאחר כריתת טחול בילדות
- ד. הרעלת ויטמין D
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Sources
- ESC Guidelines for the diagnosis and management of syncope, 2018 — Initial evaluation, risk stratification and treatment
- Harrison's Principles of Internal Medicine, 21st edition (2022) — Syncope
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.