We all know that children are a special population of humans (please don’t say “kids aren’t little adults”- it engenders fear of caring for kids instead of empowering providers for staying abreast of the issues that make caring for kids unique and special – ok… I’ll get off soapbox now), but it seems like “adult problems” are becoming more recognized in children now.  We have discussed issues like Pulmonary Embolism, Cholelithiasis, Acute Cholecystitis, and Renal Stones. Here is another item to add to that list of conditions seen commonly in adults, that may make you scratch your head if/when you encountered it with one of your pediatric patients – A-Fib in Kids:

A-Fib in Kids: Basics

• Atrial Fibrillation (A-Fib) is derived from several, small reentry circuits (unlike A-Flutter that has one reentry circuit). [Zachary, 2000]
  • It is unusual in children because the small atrial mass/size is less likely to support numerous reentry circuits.
  • When present, it leads to ineffective atrial contractions.

• A-Fib should be suspected with any irregular, narrow complex rhythm.
  • May be a rapid, normal, or even slow rate.
  • May also be associated with wide complexes if there is another concurrent conduction abnormality (ex, Wolf-Parkinson-White Syndrome).

• A-Fib in kids is most often associated with another condition: [Zachary, 2000]
  • Known congenital heart disease.
    • Most common association.
    • Particularly true in patients who have had surgical corrections / palliations.
  • Acquired heart disease
    • Atrial dilatation
    • Rheumatic heart disease
    • Cardiomyopathies
    • Myocarditis
  • Cardiac masses (act as local irritant)
    • Atrial myxoma
    • Rhabdomyoma
  • Metabolic / electrolyte abnormalities
  • Medication toxicities
    • Digoxin
    • Sympathomimetics (part of the reason we don’t recommend “cold” preparation medicines to young children)
    • Albuterol
  • Intoxicants
    • Alcohol (“holiday heart” in kids!) [Koul, 2005]
    • Cocaine and other stimulants.
  • Other systemic stressors
    • Sepsis
    • Pulmonary Embolism [Szwast, 2007]
    • Pheochromocytoma
    • Hyperthyroidism (although not as common as in adults)

Lone A-Fib in Kids

• While most often, children will have an associated underlying cardiac or systemic condition, this is not always the case. [El-Assaad, 2017; Ceresnak, 2013; Mills, 2013 ]
  • A-fib affecting previously healthy kids is referred to as “Lone Atrial Fibrillation.”
  • Prevalence found in one large study found to be 7.5 / 100,000 children. [El-Assaad, 2017]
  • Pathophysiology is likely multifactorial:
    • Atrial dilatation
    • Diastolic dysfunction
    • Genetic predisposition
      • May have a familial association.
      • Always good to ask about family history! [El-Assaad, 2017]

• Risk factors found to be: [El-Assaad, 2017]
  • Obesity (BMI >94th percentile)
  • Older children
    • Odds increased with age
    • Children 15-19 years of age with highest adjusted odds ratio
  • Male gender

• Recurrence rate of a-fib in these patients is 15% at one month, 21% at 6 months, and 23% at 12 months.
• Acute cerebrovascular stroke occurred in 2% within 1 year. [El-Assaad, 2017; Mills, 2013]
  • No consensus on use of heparin or long-term anticoagulation in these patients.

A-Fib in Kids: Management

• A-Fib that presents associated with signs of systemic instability, needs synchronized cadioversion.
• The management of stable patients with a-fib is lacking consensus, because of its rare nature. [El-Assaad, 2017]
  • Treat electrolyte derangements.
  • Consider potential for other associated causes.
  • Control rate.
  • Discuss with your friendly, neighborhood pediatric cardiologist (as her/his experience will likely determine ultimate management).
  • May need to consider Electrophysiology Study as some can have association with SVT. [El-Assaad, 2017; Ceresnak, 2013; Mills, 2013]

Moral of the Morsel

• A-fib is not just for old adults! While rare, children can develop it, even without other cardiac or systemic conditions.
• If unstable, you know what to do! Use the juice!!
• If stable, think about causes… and discuss with your pediatric cardiology friends.

References