Multifocal atrial tachycardia in infancy

Abstract

Four infants with multifocal atrial tachycardia are presented. They all displayed the typical ECG-findings of this particular form of supraventricular tachycardia: at least 3 different P-waves; varying atrial rate over 100 beats per minute; an isoelectric baseline between P-waves and a permanent variation of PP-, PR- and RR-intervals. One baby had a truncus arteriosus communis, the other 3 were healthy except for their rhythm disorder. In 2 of our patients, the multifocal atrial tachycardia was already present at birth, in the other 2 infants it became apparent at age 2 and 4 months respectively. Two children were asymptomatic, the other 2 had a slightly enlarged heart and some evidence of pulmonary venous congestion on chest roentgenogram. All 4 patients received digoxin. The tachycardia disappeared in 2 cases under but without definite causal relation to that treatment. In the 2 other cases the tachycardia persists in spite of treatment. Multifocal atrial tachycardia is a rare form of rhythm disturbance in infancy; it is difficult to treat but frequently resolves spontaneously within the first year of life.