WBR0995
| Author | [[PageAuthor::Mohamed Moubarak, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 3 |
| Main Category | MainCategory::Emergency Room |
| Sub Category | SubCategory::Cardiovascular |
| Prompt | [[Prompt::A 56 year-old female comes to ED complaining of sudden onset of dizziness and palpitation, and light headedness. These symptoms have been occurring frequently for the past 2 days, last for few minutes, and resolve spontaneously. She has a history of hypertension, and ischemic heart disease. Her current medications are daily aspirin, Metoprolol, and hydrochlorothiazide. On examination, her heart rate is 110 bpm and shows irregular irregularity, blood pressure is 130/80 mmHg, temperature is 37 C (98.6 F), and respiratory rate is 18/min. Her EKG shows atrial fibrillation, and her ventricular rate was controlled by IV diltiazem drip. Which of the following should be used to keep her sinus rhythm?]] |
| Answer A | AnswerA::Verapamil |
| Answer A Explanation | [[AnswerAExp::Incorrect
Calcium channel blockers as verapamil and diltiazem have not been shown to prevent recurrence of atrial fibrillation in patients with of paroxysmal atrial fibrillation.]] |
| Answer B | AnswerB::Diltiazem |
| Answer B Explanation | [[AnswerBExp::Incorrect
Calcium channel blockers as verapamil and diltiazem have not been shown to prevent recurrence of atrial fibrillation in patients with of paroxysmal atrial fibrillation.]] |
| Answer C | AnswerC::Amiodarone |
| Answer C Explanation | [[AnswerCExp::Correct
Amiodarone is the preferred class I anti arrhythmic drug for the maintenance of sinus rhythm.]] |
| Answer D | AnswerD::Ibutilide |
| Answer D Explanation | [[AnswerDExp::Incorrect
Ibutilide is class III anti arrhythmic that is used for the acute termination of atrial fibrillation and not for long term use.]] |
| Answer E | AnswerE::Digoxin |
| Answer E Explanation | [[AnswerEExp::Incorrect
Although digoxin is used as rate control medication, Amiodarone is the preferred class I anti arrhythmic drug for the maintenance of sinus rhythm.]] |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::The patient in this case is the classic presentation of paroxysmal atrial fibrillation, which present with recurrent episodes of palpitation which resolve spontaneously. Intravenous rate control medications should be administered in ED such as beta blockers, calcium channel blockers (diltiazem), or digoxin. Amiodarone is the preferred class I anti arrhythmic drug for the maintenance of sinus rhythm.
(Related to WBR0994) |
| Approved | Approved::No |
| Keyword | [[WBRKeyword::paroxysmal atrial fibrillation]] |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |