A 48-year-old, previously healthy woman reports having suddenly lost consciousness four times in the past 6 months. In three instances, she was unconscious for only a few minutes. After the fourth episode 1 month ago, she was unconscious for 6 hours and had weakness in her right arm and difficulty speaking. On physical examination, she is afebrile, and her blood pressure is normal. No murmurs are auscultated. She has good carotid pulses with no bruits. Which of the following cardiac lesions is most likely to be present in this woman?
A 48-year-old, previously healthy woman reports having suddenly lost consciousness four times in the past 6 months. In three instances, she was unconscious for only a few minutes. After the fourth episode 1 month ago, she was unconscious for 6 hours and had weakness in her right arm and difficulty speaking. On physical examination, she is afebrile, and her blood pressure is normal. No murmurs are auscultated. She has good carotid pulses with no bruits. Which of the following cardiac lesions is most likely to be present in this woman?
💡 Explanation
**Core Concept:** Sudden loss of consciousness, transient ischemic attacks (TIAs), and post-TIA neurological deficits can be indicative of a cardioembolic stroke. Cardioembolic strokes occur when emboli (blood clots) travel to the brain from the heart.
**Why the Correct Answer is Right:** In this case, the patient presents with transient episodes of unconsciousness and subsequent neurological deficits. The onset and resolution of symptoms, as well as the absence of fever and murmurs, suggest a cardioembolic stroke. Cardiac lesions A, B, and D are all potential causes of stroke, but the correct answer focuses on the most likely one.
**Why Each Wrong Option is Incorrect:**
A. Atherosclerosis (option A) is a narrowing of the arteries due to plaque buildup and is not typically associated with sudden loss of consciousness and short episodes of neurological deficits.
B. Hemorrhagic stroke (option B) would present with hemorrhage and associated neurological deficits, not transient episodes of unconsciousness and focal neurological deficits.
C. Multiple sclerosis (option C) is a disease characterized by inflammation and demyelination of the central nervous system, which does not explain the sudden loss of consciousness and transient neurological deficits.
D. Migraine (option D) is characterized by recurrent headache attacks and does not typically present with transient episodes of neurological deficits.
**Clinical Pearl:** Cardioembolic strokes are often secondary to atrial fibrillation, a cardiac arrhythmia that can cause blood clot formation in the heart. Transient ischemic attacks (TIAs) and stroke can occur when these clots dislodge and travel to the brain. Early recognition and management of atrial fibrillation can prevent further strokes and improve patient outcomes.
**Correct Answer:** D. Atrial fibrillation (AFib)
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In summary, the correct answer, option D, atrial fibrillation, is the most likely cardiac lesion contributing to the patient's symptoms. Atrial fibrillation is an arrhythmia that can lead to blood clot formation in the heart. These clots can dislodge and travel to the brain, causing transient ischemic attacks (TIAs) or strokes. Early recognition and management of atrial fibrillation are crucial to prevent further strokes and improve patient outcomes.
✓ Correct Answer: C. Left atrial myxoma
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