A 32-year-old woman with established nonobstructive hypertrophic cardiomyopathy (HCM) presents after an episode of palpitations associated with dizziness and chest pain. She had a single episode with palpitations and shortness of breath while at rest. She came to the emergency department and was found to have atrial fibrillation (AF) with a heart rate of 190 bpm. Sinus rhythm returns after 36 hours and initiation of a beta-blocker. No subsequent events have occurred.
She denies recent changes to her medications. She has no prior history of cerebrovascular accidents or transient ischemic attacks. She has no known vascular disease. She does not have congestive heart failure, diabetes mellitus, or hypertension. Her hypertension is managed with moderate-dose angiotensin-receptor blocker. She has a sister with AF (onset in her 50s). She is a lifelong nonsmoker, does not drink alcohol or caffeine, and does not use illicit drugs.
135/82 mm Hg
Skin (as necessary):
Head and Neck:
Jugular venous pressure 6 cm H2O, normal carotid impulses
Chest and Lungs:
Clear lung fields
Regular rate and rhythm, normal S1 and S2, no murmurs at rest or with Valsalva maneuver
Extremities (pulse, edema, etc.):
Peripheral pulses 2+ throughout
Extremities warm, well perfused, no edema
Neurologic (as necessary):
Which one of the following statements is true?
The correct answer is: C. The patient is at high risk for complications related to atrial fibrillation and anticoagulation is recommended.
Answer choice A is an incorrect choice because the AF was controlled after a beta-blocker and has not returned.
Answer choice C is the correct choice. Patients with HCM are at high risk for complications related to AF, specifically thromboembolism, and anticoagulation is recommended.
Answer choices B and D are incorrect choices because the risk of thromboembolism related to HCM and AF is independent of CHADS2VASC score and anticoagulation is recommended.
Therapy for AF in HCM includes prevention of thromboembolic stroke and controlling symptoms. Although there are no randomized controlled trials, the risk of systemic embolization is high in patients with HCM and AF. A meta-analysis of studies evaluating stroke in AF and HCM that included 33 studies and 7,381 patients revealed an overall AF prevalence of thromboembolism in patients with HCM and AF of 27.09% and incidence of 3.75% per 100 patients per year (95% confidence interval 2.88-4.61%), I-square 37.9% (p = 0.1). The stroke risk is independent of CHA2DS2-VASc score, with a significant number of strokes observed in patients with a score of 0. Publications have shown direct oral anticoagulants to be at least as effective as warfarin, with additional advantages reported such as improved patient satisfaction and long-term outcomes.
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