|CURRENT Diagnosis & Treatment: Pediatrics| Chapter 19.
Cardiovascular Diseases Disorders of Atrioventricular
ConductionShelley D. Miyamoto, MD, Henry M. Sondheimer, MD,
Thomas E. Fagan, MD, Kathryn K. Collins, MD Sections: Syncope
(Fainting). Excerpt:"The atrioventricular node is the electrical
connection between the atrium and the venticles.
Atrioventricular blocks involve a slowing or disruption of this
connection and are described according to the degree of this
slowing or disruption.The primary finding in infants and
children with complete atrioventricular block is a significantly
low heart rate for age. The diagnosis is often made prenatally
when fetal bradycardia is documented. An ultrasound is then
conducted as well as a fetal echocardiogram of the heart. With
the fetal echocardiogram, atrial and ventricular contractions
can be distinguished and the atrial rate is documented as being
higher than the ventricular rate with no relationship to each
other. If the heart rates are sufficiently low, then ther