In approximately 30 percent of patients with heart failure, an abnormality in the heart's electrical conducting system causes the two ventricles to beat slightly out of phase, or in an asynchronous fashion.  This asynchrony greatly reduces the efficiency of the ventricles.

To re-coordinate the action of the right and left ventricles, Lourdes Hospital performs cardiac resynchronization therapy (CRT-D) using a specialized pacemaker (ICD or implantable defibrillator).  The CRT-D device simultaneously stimulates the left and right ventricles and restores a coordinated or "synchronous," squeezing pattern, resulting in a more coordinated and effective heartbeat.  The defibrillator capacity of the device also can correct potentially life-threatening abnormal heart rhythms by generating an electrical pulse to zap the heart back to a normal rhythm.