Multifocal atrial tachycardia in 2 children.

The incidence of multifocal atrial tachycardia (MAT) is very low and accounts for less than 1% of supraventricular tachycardia in infants and children. In this report, the clinical characteristics, medical treatment and outcome of MAT in 2 children are described. The first patient presented with tachycardia and respiratory failure since the day after birth. First, he received amiodarone, propranolol, and digoxin and then amiodarone alone. The heart rhythm converted to sinus rhythm 2 weeks after hospitalization. Although nonsustained MAT was occasionally observed when the infant suffered from pulmonary infection, the frequency of recurrent MAT decreased as the infant grew up. The second patient was a 5-year-old girl. She had congenital heart disease with double outlets of right ventricle (DORV), patent ductus arteriosus, coarctation of aorta, and ventricular and atrial septal defects. She underwent total correction at the age of 4 years. MAT was noted 3 months after the operation with the presentation of congestive heart failure. The heart rate slowed down and returned to normal sinus rhythm within several hours after amiodarone use. The symptoms and signs of congestive heart failure also disappeared. The patient took amiodarone regularly, and no tachycardia was detected during the follow-up period. MAT is considered to be a relatively benign arrhythmia with likely good outcome if there is no severe underlying illness. It can be well controlled under appropriate drugs, and a long period of follow-up is suggested. If pharmacologic intervention is required, we suggest that amiodarone may be an excellent choice.