Tachycardia Induced Cariomyopathy in Childhood

ABSTRACT

PURPOSE: Dilated cardiomyopathy in children is usually progressive and leads to death in several years. Chronic tachyarrhythmia has been shown to cause dilated cardiomyopathy in human and animals and this ventricular dysfuntion is usually reversible after control of the arrhythmia. The uncontrolled chronic tachycardia may be a curable cause of dilated cardiomyopathy in some patients. We describe six children who had persistent chronic tachycardia and ventricular dysfunction that improve significantly after control of the arrhythmia. METHODS: We retrosepctively reveiwed the medical records, electrocardiograms, Holter recordings, Echcardiographic reports of 6 children with the tachycardia induced ventricular dysfunction who have been managed at Sejong general hospital and Asan medical center from January 1992 to June 1995. RESULTS: 1) The causes of referral were dilated cardiomyopathy in 2 and tachyarrhythmia in 4. The age at diagnosis was 4 to 36 months old and follow-up period was 6 to 29 months. The symptoms of congestive heart failure were seen in 3 children. 2) The mechanisms of thachyarrhythmia causing cardiomyopathy were atrial ectopic tachycardia in 2, chaotic atrial rhythm in 3 and junctional ectopic tachycardia in 1. Atrial ectopic tachycardia has improved after combined treatment with amidarone and atenonl. One case of chaotic atrial rhythm has improved spontaneously and other 2 cases of chaotic arial rthythm have improved after treatment with digoxin or after combined therapy with amidarone and digoxin. Junctional ectopic tachycardia is partially controlled with mexiletine. 3) The shortening fractions of left ventricle at diagnosis were 14-21% and improved to over 30% in all after 2 to 9 months of follow-up. CONCLUSIONS: We have shown that control of persistent tachycardia resolved the left ventricular dysfunction. We suggest that patients with dilated cardiomyopathy be carefully screened for tachyarrhythmia as a curable cause of ventricular dysfunction and that left ventricular function be assessed in the asymptomatic patients with persistent tachycardia.