Cardiac resynchronization therapy in pediatrics: emerging technologies for emerging indications.

Cardiac resynchronization therapy (CRT) has become the standard of care for the treatment of heart failure in adults with decreased ventricular function and conduction delay who remain symptomatic despite optimal medical therapy. Indications for CRT in adults include medically refractory heart failure with a QRS duration of >or=120 msec and a left ventricular end-diastolic dimension of >or=55 mm with ejection fraction <or=35%. No such consensus guidelines exist in pediatrics; however, recent preliminary data indicate that CRT is effective therapy for symptomatic heart failure in children in both the acute postoperative setting as well as in the ambulatory setting. CRT is a viable therapeutic option in children with decreased ventricular function and ventricular conduction delay. It is preferable to high-dose inotropic therapy and should be given serious consideration for the treatment of refractory heart failure prior to proceeding with heart transplantation.