Transvenous Biventricular Pacing in Children. Cardiac resynchronization therapy improves short-term and long-term hemodynamics in adult patients with congestive heart failure and left bundle branch block. We describe the feasibility of transvenous biventricular pacemaker implantation in a 6-year-old child with heart failure and wide QRS complex after congenital heart surgery. Myocardial tissue Doppler imaging was used to demonstrate intraventricular dyssynchrony and resynchronization after cardiac resynchronization therapy. During 1-year follow-up, symptomatology and hemodynamic parameters improved.