Resynchronization or dyssynchronization--successful treatment with biventricular stimulation of a child with obstructive hypertrophic cardiomyopathy without dyssynchrony.

We present a case of a 10-year-old boy with hypertrophic cardiomyopathy, intraventricular pressure gradient of 104 mmHg, and indications for prophylactic ICD implantation. Based on intraoperative pressure measurements, the child was implanted with biventricular ICD. During 2.5 months of observation, the patient's functional status improved significantly, as shown by subjective and objective parameters and, moreover, the pressure gradient fell to 12 mmHg. Significant electrical and mechanical cardiac dyssynchrony appeared parallel to clinical improvement.