Low pulse rates, or bradycardia, can be caused by multiple conditions in children. Normally, electrical signal in the heart control the rate of contraction. Disruption of these pathways can cause a low pulse rate. Recognition of the signs and symptoms of low pulse rate and early diagnosis and treatment can minimize the impact of this condition on your child.
Definition
Heart rates vary with age. Therefore, limits for defining low pulse rates will be different as your child grows. Newborns can have normal heart rates as high as 140 beats per minute, much higher than the normal heart rate of about 72 in older children and adults. A pulse rate less than 80 beats per minute defines bradycardia in children younger than 3 months, according to Children's Healthcare of Atlanta. In children older than 3 months, bradycardia is defined as a pulse rate less than 60. Short drops in pulse rate, less than five to 10 seconds, can be considered normal.
Symptoms
Bradycardia may produce no signs or symptoms in young healthy persons or in athletes. Very low pulse rates or bradycardia caused by pathologic conditions can cause dizziness, weakness, fatigue, shortness of breath and fainting. In children, symptoms may become evident during times of play or strenuous activity, according to the MayoClinic.com.
Causes
Low pulse rates in children can be caused by any disturbance that disrupts the normal electrical activity of the heart. Structural causes can be due to congenital defects or damage to the heart by injury or infection. Additionally, according to the MayoClinic.com, changes in circulating hormone levels or the levels of electrolytes needed by the heart can cause low pulse rates.
Diagnosis
Following identification of a low pulse rate, your child's doctor will order tests to attempt to identify the underlying cause of your child's bradycardia. The electrocardiogram, or EKG, is commonly used to identify the cause of low pulse rates. Electrocardiograms utilize sensors placed on the skin that can detect the electrical activity in the heart. A specific type of electrocardiogram often used is the Holter monitor. This portable electrocardiogram can measure pulse rate and the electrical activity in the heart over the course of a whole day. Other diagnostic measures include blood tests and echocardiograms.
Treatment
In most cases, treatment targets the underlying cause of your child's low pulse rate. Correction of altered hormone or electrolyte levels can often return the pulse rate to normal, according to the Mayo Clinic. Removal of medicines that may affect the heart or administration of certain antiarrhythmics may improve pulse rate. If these interventions fail, a pacemaker may be implanted. Pacemakers are electrical devices implanted under the skin with wires leading to the heart. The electrical signals produced by the pacemaker cause the heart to contract at a normal rate.
