Causes Of Bradycardia In Newborns: Diagnosis And Treatment

Bradycardia in newborn is defined as slowdown of heart rate below 100 beats per minute. Newborn especially premature babies often suffer from bradycardia. This is frequently accompanied with interruption in breathing. In medical terminology such pauses are referred as apnoea. Such breaks in breathing mechanism may occur for few seconds in which case the baby has to gasp for air. Lack of oxygen during this period often turns the baby blue or pale.

The primary reason for bradycardia is hypoxia (deficiency of oxygen in the body). There are several other reasons that can cause bradycaria in newborn infants.

This includes hypothermia (low body temperature), hypovolemia (low level of blood and fluid volume), brain injury, infection etc.

Treatment consists of administration of medicines that stimulate breathing and normalize heart beats. Additonally mechanical ventilation may be necessary to maintain airway patency.

What Causes Bradycardia In Newborns?

Those infants and newborns who have bradycardia also have accompanied apnea in most of the cases. It is more common in premature neonates. However, prematurity is not the only reason. Bradycardia and breathing irregularity can also occur in other conditions such as infection, low blood sugar, insufficient oxygen in the body, etc.

In preterm the problem is found to be common because of two reasons. Firstly the nervous system in premature babies is not developed completely. The area in the brain which controls respiration is hence not fully functional. Thus the baby may have shallow or pauses in breathing. Secondly babies with low birth weight, especially those with less than 5.5 pounds have some amount of apnea. This may also cause associated bradycardia.

The above two causes for bradycardia are more common in premature babies but there are several other causes that are responsible in full term babies. For example:

  • Serious infection such as meningitis and pneumonia.
  • Low body temperature
  • Low blood sugar
  • Seizure
  • Obstruction in air passage.
  • Accumulation of fluid in brain.
  • Gastric reflux
  • Condition of gastrointestinal system called necrotizing enterocolitis.
  • Drug addiction by mother during pregnancy.
  • Bleeding inside the brain due to injury.
  • A hole in heart
  • Lung collapse
  • Increased intracranial pressure.

Diagnosis And Treatment Of Bradycardia In Infants

If the newborn has persistent less than 90 beat per minute of heart rate, he needs to be assessed and investigated. There is a need to rule out any cardiac or non cardiac cause for bradycardia. The doctor first takes careful medical history which consists of several aspects such as history of any drugs taken during pregnancy by the mother, any diseases suffered by the mother during pregnancy, details of labor period etc.

Once the details of history and examination are taken, treatment consists of administration of drugs that help to stimulate breathing and correct the heart rate. Besides medicines, stroking gently the back and feet will also stimulate breathing. Mechanical ventilation may be necessary to maintain correct heart respiratory and heart rate.