Findings in the Dissection Lab
are implanted in a pocket of skin or subcutaneously over the pectoralis
major. The leads are inserted into the left subclavian vein and pass through
the left brachiocephalic vein and the superior vena cava, and into the
right atrium. The smaller pacemaker shown below had a single lead that
passed that passed through the tricuspid valve and was implanted into the
interventricular septum. If a second lead is implated it might be implanted
in the interatrial septum.
The larger pacemaker shown below is an older model and had two leads passing
into the heart. Newer pacemakers are programmed from outside the body and can
correct a wide range of arrhythmias.