Cardiac resynchronization therapy (CRT) is treatment to help your ventricles beat or pump in sync. The CRT device it there to coordinate the timing of the upper and lower chambers. I have this setup in me, a CRT-D w/ 3 leads. It has a defibrillator in case I go into cardiac arrest, it's supposed to shock the heart. New tech is available, get rid of the old pacemaker, the newer unit will help your heart pump more efficiently. Mine has bluetooth built in, I can monitor certain things, even battery life on my phone. Mine is doing a good job, especially with my low EF of 20.

Do you mean a Bi V wire?