A pacemaker may be recommended if your heart does not beat in a normal rhythm, commonly referred to as arrhythmia. Changes in the electrical impulses within the heart may be the cause of the arrhythmia. Specific reasons you may need a pacemaker include:
- Your heartbeat is not fast enough (Bradycardia)
- Your heartbeat is irregular
- The pathways that carry the electrical impulses through the heart are blocked
Symptoms of heart rhythm disturbances may include fatigue, dizziness, fainting, shortness of breath and heart palpitations.
A traditional pacemaker is a small electrical device that is placed just under the skin on your chest just below the collarbone. Pacemakers have conventionally been about the size of two silver dollars and are battery-powered, sending out electrical impulses to keep the heart beating in a normal rhythm.
The pacemaker is made up of a pulse generator, which produces the electrical signals and one or more electrodes (wires) that deliver the electric signals to the heart.
When it is in place, the pacemaker senses your heartbeat continuously. If it notices a departure from normal rhythm, it sends a signal out to stimulate the heart back to a normal rhythm.
Pacemakers can either be Single Chamber or Dual Chamber devices. With a single chamber pacemaker there is only one electrical lead wire that is typically placed in the right ventricle. With a dual chamber, there are two leads which are normally placed one in the right atrium and one in the right ventricle. The type of pacemaker right for you depends on what kind of arrhythmia you are experiencing.
New, smaller pacemakers have recently been developed in the Single Chamber category. The Micra ™ Transcatheter Pacing System is one example of this new type. It is 93% smaller than a traditional pacemaker; about the size of a large vitamin capsule.
Instead of the traditional implantation method of opening a pocket in the skin over the collarbone, this type of pacemaker is implanted directly in the heart through a catheter inserted in a vein in the upper leg.
This smaller pacemaker is moved into position against the heart wall of the right ventricle and secured. With this type of pacemaker, there is no visible sign of the pacemaker under the skin.
After placing the pacemaker, the physician performs tests to ensure it is functioning correctly and then removes the catheter tube from the body.
At this time, the mini pacemaker is only used in instances where the patient needs a single chamber pacemaker.