WBR0841

Author	Neeraja Danda M.B.B.S
Exam Type	USMLE Step 2 CK
Main Category	Internal medicine
Sub Category	Cardiovascular, Endocrine
Prompt	A 35 year old female presents to her physician’s office complaining of a racing heart for the last 3 days. She also complains of heat intolerance and loss of weight, irregular menstrual cycles for the last 6 months. On physical exam, her blood pressure is 110/70, pulse rate 170 irregularly irregular, and respiratory rate 20/ min. An electrocardiogram is performed which shows absent P waves, narrow QRS complexes and irregular R-R intervals. What is the most appropriate next step in the management of this patient?
Answer A	Thyroxine
Answer A Explanation	Incorrect Thyroxine is the treatment of choice for hypothyroidism not hyperthyroidism.
Answer B	Beta blocker
Answer B Explanation	Rate controlling drug like beta blocker is used to treat atrial fibrillation in hemodynamically stable patient.
Answer C	Cardioversion
Answer C Explanation	Incorrect Cardioversion is the treatment of choice in unstable patients with atrial fibrillation.
Answer D	Warfarin
Answer D Explanation	Incorrect Warfarin can be used for anticoagulation once the rate control is achieved.
Answer E	Holter monitoring
Answer E Explanation	Incorrect If the electrocardiogram was normal then holter monitoring may be opted to know the episodes of atrial fibrillation in 24 hours.
Right Answer	B
Explanation	Irregularly irregular 170 pulse rate and the electrocardiogram findings suggest atrial fibrillation in this patient. Hyperthyroidism may be suspected as an underlying cause based on her history of heat intolerance, irregular menstrual cycles and weight loss. The patient has experienced tachycardia for 3 days so the treatment of choice will be a rate controlling drug such as a beta blocker. Educational Objective: Atrial fibrillation in hemodynamically stable patient is managed with rate controlling medication such as beta blockers. References:Page 72 Master the boards step 3 2009, Page 554 Master the boards step 2 CK second edition Educational Objective: References:
Approved	Yes
Keyword	Beta blocker, Atrial fibrillation
Linked Question
Order in Linked Questions