To determine an infant’s vital signs, health-care providers check a pulse rate. A pulse tells how fast the heart is beating and if it is in a normal rhythm. Babies have the fastest pulse rate right after birth, and it will continue to slow as they grow into childhood. A normal pulse rate for an infant is much faster than that of an adult. Checking a pulse and knowing a normal rate is a quick way to determine one of a baby’s vital signs.
Pulse
A pulse measures the beat of a heart, which is each individual contraction of the muscle. Blood enters the heart on one side and it circulates through a series of four chambers while restoring oxygen. A contraction of the heart is when blood is pumped out into the rest of the body to oxygenate the tissues. Oxygenated blood is carried through the body by arteries. Some arteries run close to the surface of the skin and can be felt by placing two fingers over a specific site on the body. This process is feeling a pulse and it allows for measurement of heart beats. Conditions called arrhythmias may cause a pulse rate to run faster or slower than normal.
Normal Values
An infant’s pulse rate runs higher than that of a child or adult. To feel the pulse of an infant, place two fingers on the inside of the upper portion of the arm. This is the brachial pulse, which is the most common site of palpation for an infant. Pulses in an infant may also be felt at the top of the leg, next to the groin, which is called a femoral pulse. The average pulse rate for an infant is 140 beats per minute, which slows as a baby gets older. By 12 months of age, a baby has an average pulse rate of 115 beats per minute, says the Basic Clinical Skills website.
Bradycardia
A pulse rate that is lower than normal is known as bradycardia, which is a condition caused by a heart arrhythmia. Arrhythmias cause a disruption in the electrical system of the heart, causing abnormal pulse rates. A heart rate that is too slow may not adequately perfuse the tissues of the body with blood, which can affect brain function. The arrhythmia that causes bradycardia is typically the result of congenital heart disease and the infant is born with the condition. It may also occur when a baby is severely ill or has had a surgical procedure, advises kidshealth.org.
Tachycardia
A fast heart rate above normal in a baby is called tachycardia. Tachycardia can occur sporadically during situations such as crying, which may increase the heart rate. After calming, a brief episode of tachycardia related to activity should resolve quickly. Occasionally, a baby’s heart rate can be dangerously fast, with pulse rates over 280 beats per minute. This condition is called supraventricular tachycardia, or SVT. The rapid heart rate may occur in babies intermittently and is associated with pale skin, lethargy, and poor feeding. Prolonged episodes of SVT may need treatment with medication, but if a baby is born with the arrhythmia that causes this condition, it frequently resolves by 18 months, the University of Michigan says.
Treatments
Treatment of an abnormal pulse depends on the cause. According to Penn State Children’s Hospital, medications are used to treat an abnormally slow or fast pulse when symptoms appear that are a danger to a baby’s health. Medications can be used to regulate the heart rate of a baby in order to prevent dangerous effects of arrhythmia, such as less oxygen in the baby’s tissues. Other procedures may also be done to treat pulse irregularities, such as a small electric shock that normalizes the heart’s activity, or inserting a pacemaker to regulate a pulse.
