A 35-year-old woman comes to the office for a routine physical examination. She is in good health and has no significant medical history. The patient does not use tobacco or alcohol. She takes no medications or supplements. Her paternal aunt had an unexpected death at age 32. Physical examination, including cardiac examination, is unremarkable. ECG shows normal sinus rhythm with a corrected QT interval of 505 msec. Serum electrolytes are normal. Echocardiogram shows normal heart structure and function.
The patient is advised about lifestyle modification and medication safety. Which of the following is the best initial management for this patient?

Question

A 35-year-old woman comes to the office for a routine physical examination.  She is in good health and has no significant medical history.  The patient does not use tobacco or alcohol.  She takes no medications or supplements.  Her paternal aunt had an unexpected death at age 32.  Physical examination, including cardiac examination, is unremarkable.  ECG shows normal sinus rhythm with a corrected QT interval of 505 msec.  Serum electrolytes are normal.  Echocardiogram shows normal heart structure and function.
The patient is advised about lifestyle modification and medication safety.  Which of the following is the best initial management for this patient?

Quizplus · Accepted Answer

11ec193a_9772_71f4_853d_5d8ba295b6f3_MD0002_00 This patient's presentation - prolonged corrected QT interval (QTc) and family history of sudden death - is suggestive of congenital long QT syndrome (LQTS). A normal QTc interval is 370-440 msec. A QTc >450 msec in male patients and >470 msec in female patients is considered a prolonged QT interval. Patients with congenital LQTS may be asymptomatic or have palpitations, presyncope/syncope, seizures, or cardiac arrest. LQTS is associated with an increased risk of ventricular arrhythmias, such as torsades de pointes, which may terminate spontaneously or degenerate into ventricular fibrillation. QT interval Management includes avoidance of conditions (eg, strenuous exercise, electrolyte abnormalities such as hypokalemia or hypomagnesemia) and medications (eg, antipsychotics, fluoroquinolones) that may prolong the QT interval. Current guidelines also recommend that all patients with congenital LQTS (symptomatic or asymptomatic) be treated with beta blockers (eg, propanolol, nadolol) to decrease the risk of symptomatic arrhythmias and sudden cardiac death (Choice E). (Choice A) Diltiazem is commonly used to treat supraventricular tachycardias. It has no role in the management of patients with LQTS. (Choice B) Disopyramide is a class Ia antiarrhythmic agent that can cause further prolongation of the QT interval. (Choice C) An implantable cardioverter-defibrillator (ICD) is recommended for patients with LQTS who have syncope (especially if recurrent) or ventricular tachycardia (eg, torsade de pointes) on beta blocker therapy. ICDs may be considered in patients with a strong family history of sudden cardiac death. However, a beta blocker should be used as initial treatment for this patient, particularly given the risks associated with ICD placement (infection, lead fracture). ICDs are also used as secondary prevention in patients with an aborted cardiac arrest. Educational objective: Beta blockers are recommended for patients with congenital long QT syndrome to reduce the risk of symptomatic arrhythmias and sudden cardiac death. An implantable cardioverter-defibrillator is recommended for patients with syncope (especially if recurrent) or ventricular tachycardia (eg, torsade de pointes) on beta blocker therapy or for those with aborted cardiac arrest. __________ References: Congenital long QT syndrome: considerations for primary care physicians. (http://www.ncbi.nlm.nih.gov/pubmed/18756841)

A 35-Year-Old Woman Comes to the Office for a Routine