Long QT3 is characterized by a defect in which of the following?

1. KCNQ1-encoded slow component of the delayed rectifier potassium current (IKs)
   
2. KCNH2-encoded rapid component of the delayed rectifier potassium current (IKr)
   
3. SCN5A-encoded sodium channel
   
4. None of the above

Brugada syndrome is associated with a mutation in which of the following?

1. Voltage-gated sodium channel
   
2. L-type calcium channel
   
3. SCN5A-encoded sodium channel
   
4. Potassium channel

Which of the following is not an indication for an implantable cardioverter-defibrillator (ICD) in a patient with long QT syndrome?

1. Aborted cardiac arrest (regardless of genotype)
   
2. Episode of ventricular tachycardia (VT) despite being on optimal medical therapy
   
3. Symptomatic with a QTc of greater than 550 ms
   
4. Symptomatic long QT2, diagnosed with cancer with a life expectancy of 6 months

A 40-year-old male is being evaluated for symptoms of syncope. He has had three episodes of witnessed syncope. His electrocardiogram (ECG) shows normal sinus rhythm with an incomplete right bundle branch pattern and coved ST segment elevation in the right precordial leads. His father was diagnosed with Brugada syndrome at age 30. His father’s ECG was also characteristic for right bundle branch block pattern with coved ST elevation in the right precordial leads. What should his management at this time be?

1. Reassurance and ask to come back for a follow-up in 1 year
   
2. Beta-blocker therapy
   
3. Implantable-defibrillator therapy
   
4. Genetic testing

A 20-year-old female is being evaluated for syncope. She gives a history of passing out with exercise. Her maternal aunt, who is aged 35 years, also has a history of syncope. Her aunt’s symptoms started soon after she delivered her first baby. She also had an aborted cardiac arrest and had an ICD placed. Her cousin, who is aged 25 years, also has a history of syncope. She passes out whenever she hears the doorbell or telephone ring. Her history and physical exam are otherwise unremarkable. What is the best therapy at this time?

1. Implantable defibrillator
   
2. Beta-blocker therapy
   
3. Mexiletine
   
4. Reassurance and follow-up in 1 year