Specific Conditions

Question 1

Name 3 diagnostic modalities for fetal arrhythmias

Answer 1

1. fetal echocardiography 2. fetal ECG (rarely done) 3. fetal magnetocardiography 4. fetal heart rate monitoring

Question 2

Fetal bradycardia may be associated with what important conditions?

Answer 2

1. LQTS 2. SSA/Ro or SSB/La antibody isoimmunization 3. noncompaction syndrome

Question 3

What is the combined fetal and neonatal mortality in the setting of complex CHD and fetal heart block

Answer 3

>80%. Glatz AC, Outcome of high-risk neonates with congenital complete heart block paced in the first 24 hours after birth. J Thorac Cardiovasc Surg 2008

Question 4

Which of the following has the best prognosis? Worst? a. nonisoimmune atrioventricular block b. isoimmune atrioventricular block c. left atrial isomerism and structural heart disease d. levo-transposition of the great arteries

Answer 4

Best: a. nonisoimmune atrioventricular block Worst: c. left atrial isomerism and structural heart disease

Question 5

In what percentage of pregnancies with SSA/ Ro or SSB/La autoantibodies will the fetus will develop atrioventricular block.

Answer 5

about 2%

Question 6

What is the risk of recurrence for atrio-ventricular block when a prior fetus has been affected?

Answer 6

about 20%

Question 7

Apart from fetal hydrops what is the most severe complication from isoimmune disease?

Answer 7

Prolongation of the QT interval. In one study 14/19 patients (with or without heart block) had QT prolongation > 500 ms. Zhao H. Fetal cardiac repolarization abnormalities. Am J Cardiol 2006

Question 8

Name 9 postnatal manifestations of isoimmune fetal heart block.

Answer 8

1. neonatal lupus rash 2. hepatic dysfunction 3. development of dilated cardiomyopathy 4. sinus bradycardia 5. a prolonged corrected QT interval, 6. cardiac malformations, such as patent ductus arteriosus or atrial septal defect, 7. endocardial fibroelastosis, 8. rupture of the cordae tendonae 9. systemic growth restriction among others

Question 9

Why is procainamide not used to treat fetal tachycardia?

Answer 9

Procainamide can cause maternal uterine contractions.

Question 10

Name three factors related to pregnancy that make arrhythmias more prevalent in this condition.

Answer 10

1. Stretch mediated EADs, DADs, slowing of conduction
2. Increase in adrenergic receptors by estradiol
3. higher resting heart rate

Question 11

True or False: DCCV should be avoided at all costs in a pregnant women due to high risk of injuring the fetus?

Answer 11

False. Urgent cardioversion for unstable rhythms should be performed regardless of stage of pregnancy. Elective cardioversion can be considered but can theoretically cause preterm labor in later stages. DCCV does not seem to negatively impact the fetus (too far away)

Question 12

Which one of the following beta-blockers should be avoided in pregnancy?

A. Timolol

B. Atenolol

C. Metoprolol

D. Nadolol

E. Propranolol

Answer 12

Answer: B (atenolol)

Atenolol is pregnancy class “D”. All of the other betablockers are class “C”

Question 13

What is the drug of choice for stable pre-excited Afib in pregnancy?

Answer 13

Procainamide (with or without pregnancy). DCCV might be a better option in pregnancy. Remeber than AV nodal blocking agents such as betablockers, verapamil, digoxin are all contraindicated in this scenario.

Question 14

What happens to cirulating blood volume in pregnancy and when does the effect peak?

Answer 14

Increases in effective circulating blood volume of 30% to 50%
are seen beginning at 8 weeks of gestation and peaking at ≈34
weeks.

Question 15

What condition might lead to new onset atrial fibrillation in pregnancy?

Answer 15

Given the increased risk of venous thromboembolism
during pregnancy, any pregnant woman with new-onset AF should have pulmonary embolism excluded as a cause.

Question 16

What is the preferred betablocker during pregancy in patients with LQTS?

Answer 16

Propranolol. Remeber atenolol is category D and metoprolol is felt to be less effective as a rx for LQTS

Question 17

According to a study by Mark link in October 2009 in heart rhythm, is precordial thump and effective means of terminating ventricular fibrillation?

Answer 17

In a pig model, a precordial strike from a very intensities over 180 applications did not result in termination of ventricular fibrillation

Question 18

According to research done by Mark Link using a pig model for comotio cortis how does a ball strike to the chest cause sudden death?

Answer 18

A critically timed impact to the chest with a baseball or lacrosse ball timed to the early part of the upstroke of the T-wave can result in ventricular fibrillation

Question 19

Poorly controlled epilepsy is associated with an increased risk of sudden death. Most commonly, sudden death episodes in epilepsy appear to be from bradyarrhythmias and apnea, however a subset might be due to ventricular tachyarrhythmias. By what mechanism might epilepsy cause ventricular tachyarrhythmias?

Answer 19

In a study in the August 2015 issue of circulation A & E, researchers found evidence of neuronal sodium channel expression in rat cardiomyocytes. These abnormally active sodium channels prolong the action potential in a manner similar to that seen in long QT III. Epilepsy may result in alteration in sodium channel expression in cardiac muscle . This could contribute to a risk of ventricular arrhythmias

Question 20

What is the risk of heart block following Device perimembranous VSD closure?

Answer 20

~1%. According to a large single center series of over 1000 patients. Most episodes occurred within 30 days but a few were as late as 1 year out. Only about half required permanent pacemaker as some recovered with corticosteroid therapy.