Biventricular Pacemaker or Cardiac Resynchronization Therapy (CRT)
Biventricular pacing is also known as cardiac resynchronization therapy,
as it can restore the normal heart electrical synchrony. When a bundle branch block is present, electricity
only flows down one side of the heart and slowly goes over to the other side (you can have a left or a right sided block).
This makes the heart less efficient, as the contraction of the muscle is out of synch. In patients with heart failure
and low ejection fraction (<35%), this special pacemaker helps improve symptoms and quality of life, and decreases
the chance of being hospitalized or dying from heart failiure.
A biventricular pacemaker is inserted just like other pacemakers, with one exception: a third
lead is used. With this pacemaker, there is a lead to the left ventricle and one to the right ventricle, as well
as a lead to the atrium, or top chamber. The left and right lead actively pace the ventricles at the same time.
With this pacemaker, it is almost always "on" and pacing, rather than just "as needed". This will maintain the synchrony
of the left and right ventricles, which can actually improve heart function (ejection fraction) over time.
