Brief Loss of Consciousness

April’s Case: It is a busy day in your ED when a 51-year-old woman arrives by EMS. She felt faint while riding her racing bicycle and got off just before losing consciousness. EMS found her conscious, but pale, with a heart rate, 50 beats/min; blood pressure, 90/50 mm Hg; respiratory rate, 25 breaths/min; and oxygen saturation, 98% on room air. EMS provided 1 liter of normal saline without a change in her vital signs. In the ED, her BP is still 90/50 mm Hg. She tells you that just before she got off her bike, she experienced pain in her throat, but she denies chest pain, shortness of breath, or headache. She appears uncomfortable and complains of persisting throat pain and states she is afraid of dying. Her initial ECG shows a sinus bradycardia but is otherwise normal. Her past medical history is not significant. She takes no medications. She is an experienced marathon runner and has never had similar complaints. You wonder what could have caused the syncope and persistent bradycardia.

Share your diagnosis with us in the comments box below. The case conclusion will be published on April 7!

Last Updated on January 26, 2023

14 thoughts on “Brief Loss of Consciousness

  1. Patient may have experienced a right sided NSTEMI causing her to have throat pain, leading to the bradycardia, and a possible transient vfib/vtach arrhythmia that led to her loss of consciousness. Patient needs basic labs, cardiac enzymes, d-dimer and a CXR ordered. I would continue to IVF boluses to keep her BP elevated.

  2. Vasovagal stimulation in the neck region. Need to check for anything protruding into this area. Bradycardia is probably normal for this patient ad she is a marathon runner.

  3. First of all, when is it not a busy day in my ED.
    Bradycardia not unusual in a marathon runner. Hard to judge BP significance in this athletic woman, though it is toward the low side.
    Will assume hyperextended position of neck while on racing bicycle is at the bottom of her symptoms.
    Consider carotid artery dissection (even though no focal neuro sx) – would need to start with CTA of neck, or MRI; or hypersensitive carotid bulb – sx reproduced with mild carotid massage.

  4. A: rule out ACS, PE, dissecting carotid, thoracic aortic aneurism

    P: Cardiac enzymes, basic labs, chest xray, series ecgs and chest CT angiogram, consider carotid angiogram, closely monitor

  5. The working dx is : reflex syncope with bradycardia, which could be vasovagal, carotid baroreceptor sensitivity, carotid artery dissection, or myocardial infarction (even with normal ST segments) affecting the conduction system. The throat pain is concerning and could represent angina.
    The patient needs ASA, serial enzymes, EKG’s and maybe 0.4 mg atropine. Beta blockers and nitrates for now would be contraindicated.

  6. Inferior wall MI- likely Impending STEMI,
    pt showing bradycardia, throat pain, and feeling of Doom…
    likely ECG changes yet would be evident in serial further ECGs
    2 out of 3 criteria to be met for cardiac Hx
    rising trop, chest pain (cardiac sounding pain), ECG changes

Leave a Reply

Your email address will not be published. Required fields are marked *