[Supraventricular tachycardia in newborn infants and infants].

Four types of supraventricular tachycardia were identified in a retrospective study of 71 babies who presented under the age of 3 months. The arrhythmia originated in the atrium in the first two types (25% of cases, atrial tachycardia 10 cases, chaotic atrial tachycardia 7 cases). In the other types the arrhythmia originated at the atrioventricular node. Reciprocal rhythms were most common (62%) and those starting in the bundle of His the least common (5%). It is relatively easy to distinguish the different types which are important because treatment may vary. Overall 75% recover completely, 11% have sporadic recurrences and 10% have a chronic arrhythmia. The junctional varieties have the worst prognosis.