From the Guidelines
Heart block in a 14-month-old child is most commonly caused by congenital heart defects, particularly those affecting the cardiac conduction system, with congenital complete heart block being a significant concern, as indicated by the task force on sudden cardiac death of the European Society of Cardiology 1. The causes of heart block in a child of this age can be multifaceted, including:
- Congenital heart defects, especially those involving the cardiac conduction system
- Surgical procedures to correct congenital heart defects that may inadvertently damage the conduction system
- Infectious causes such as myocarditis from viral infections or Lyme disease
- Certain medications given to the mother during pregnancy or to the child, including digoxin, beta-blockers, and calcium channel blockers
- Metabolic disorders like glycogen storage diseases or mitochondrial disorders that can affect cardiac conduction
- Inflammatory conditions such as Kawasaki disease
Evaluation and Treatment
Evaluation typically includes:
- ECG
- Echocardiogram
- Possibly genetic testing Treatment depends on the severity and cause, ranging from observation for mild cases to pacemaker implantation for complete heart block causing symptoms or bradycardia, with the most recent guidelines suggesting that pacing in children, adolescents, and patients with congenital heart disease may be classified into symptomatic sinus bradycardia, the bradycardia-tachycardia syndromes, and advanced second- or third-degree AV block, either congenital or postsurgical 1. The decision to implant a pacemaker in a child should be based on the correlation of symptoms with relative bradycardia, considering the age-dependent clinical significance of bradycardia and the technical challenges associated with device and transvenous lead implantation in very small patients or those with abnormalities of venous or intracardiac anatomy 1.
From the FDA Drug Label
Atropine also may lessen the degree of partial heart block when vagal activity is an etiologic factor The causes of heart block in a 14-month-old child may include vagal activity as an etiologic factor, as atropine may lessen the degree of partial heart block in such cases 2.
- Vagal activity is a possible cause of heart block in this age group.
From the Research
Causes of Heart Block in a 14-Month-Old Child
The causes of heart block in a child can be attributed to various factors. Some of the possible causes include:
- Autoimmune-related conditions, as mentioned in 3
- Congenital heart block, which can occur with or without structural heart abnormalities, as stated in 3
- Acquired and reversible causes, such as those resulting from myocarditis, infectious endocarditis, or electrolyte disturbances, as discussed in 4 and 5
- Infiltrative cardiac disease or non-ischemic cardiomyopathy, as noted in 5
- Drug side effects, which can also contribute to the development of heart block, as mentioned in 5
Specific Types of Heart Block
There are different types of heart block, including:
- First-degree atrioventricular block
- Second-degree atrioventricular block
- Third-degree atrioventricular block, also known as complete heart block, as described in 5 and 6 Each type of heart block has distinct characteristics and may require different management approaches, as discussed in 4 and 5
Importance of Evaluation and Management
A thorough evaluation is necessary to determine the underlying cause of heart block and to guide management decisions, as emphasized in 4 and 3. This may involve diagnostic testing, such as electrocardiography, and monitoring for progression of the condition. In some cases, treatment may be necessary to prevent complications or improve symptoms, as noted in 4 and 5