Cardiology MCQ 21.4.15

CARDIOLOGY MCQ & REVIEW

Q. All of the following statements about atrial flutter – fibrillation in WPW syndrome are correct except

A. Atrial fibrillation can precipitate ventricular fibrillation in patients with accessory pathways

B. The incidence of atrial flutter and/or fibrillation appears to be higher in patients with A-V bypass tracts than in the normal population

C. Prevalence of atrial fibrillation is same in patients with manifest preexcitation and those with concealed preexcitation

D. Atrial flutter-fibrillation may be the presenting arrhythmia in 5% to 10% of patients with A-V bypass tracts

Explanation:

-In patients with WPW syndrome atrial flutter and fibrillation are less common presenting arrhythmias, but they are potentially more life threatening, because they can result in extremely rapid ventricular rates that precipitate ventricular tachycardia and/or fibrillation

-Atrial flutter-fibrillation may be the presenting arrhythmia in 5% to 10% of patients with A-V bypass tracts and occurs even more commonly when orthodromic or antidromic tachycardia also is present

-As many as 50% of patients with symptomatic arrhythmias will have atrial fibrillation of variable duration at some time.

-The incidence of atrial flutter and/or fibrillation appears to be higher in patients with A-V bypass tracts than in the normal population

-Atrial fibrillation appears to be five times more common when overt preexcitation (i.e., WPW) is present than in patients with concealed bypass tracts at similar locations and similar rates of tachycardias

-Patients with atrial fibrillation have a higher incidence of inducible atrial fibrillation than those without the arrhythmia

1. Klein GJ, Bashore TM, Sellers TD, et al. Ventricular fibrillation in the Wolff-Parkinson-White syndrome. N Engl J Med 1979;301:1080–1085.
2. Cosio FG, Benson DW Jr, Anderson RW, et al. Onset of atrial fibrillation during antidromic tachycardia: association with sudden cardiac arrest and ventricular fibrillation in a patient with Wolff-Parkinson-White syndrome. Am J Cardiol 1982;50:353–359.
Answer: C
Keywords: Cardiology review, Cardiology, Multiple choice questions, medical students, Electrophysiology, Atrial fibrillation, WPW syndrome

 

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