Intracardiac rhabdomyomas producing symptoms in infancy: the role of radiofrequency catheter ablation.

BACKGROUND

Cardiac rhabdomyomas, although benign, may produce symptoms related to arrhythmia or mechanical obstruction. Surgical excision is the therapy of choice for symptomatic rhabdomyomas in infancy.

METHODS

Two infants with intracardiac rhabdomyomas producing symptoms underwent radiofrequency catheter ablation of the tumour. In patient 1 the diagnosis of multiple rhabdomyomas associated with recurrent supraventricular tachyarrhythmias and foetal hydrops was made in utero. After birth, several antiarrhythmic agents were administered, without successful suppression of the tachyarrhythmia. At seven months of age, the infant had one large residual tumour on the left atrial aspect of the anterior mitral valve leaflet with associated pre-excitation and re-entrant supraventricular tachyarrhythmia suggestive of a left-sided pathway. Catheter ablation of the accessory pathway was performed via a retrograde femoral arterial approach, targeting the earliest site of ventricular activation. Patient 2 presented as a neonate with multiple rhabdomyomas, one of which, measuring 15 mm × 15 mm, was producing severe mitral valve inflow obstruction resulting in symptoms of heart failure due to a large left-to-right shunt at atrial level and persistent pulmonary hypertension. Via the femoral vein, a 5F ablation catheter was advanced across the atrial septum, and the tumour directly ablated.

RESULTS

Echocardiography performed 24 hours later demonstrated alteration in tumour morphology, with the development of a large central echolucent area, followed by progressive tumour shrinkage in both infants. Patient 1 was discharged at 24 hours, and patient 2 at seven days post-ablation, without symptoms. Follow-up at four weeks confirmed further tumour shrinkage.

CONCLUSIONS

Transcatheter tumour ablation may be beneficial in selected infants and children.