Pacemaker – have you heard of this device before? Here I will discuss what it is, how it is implanted and what precautions you need to take if you have one.
The human heart beats at a rate of 60 to 100 beats per minute at a regular pace. At times, the heart can slow down to a rate that is lower than the normal. When this happens, patients may experience symptoms such as dizziness, breathlessness or lightheadedness. Some patients may even collapse.
Patients in whom the heart rate is too slow or irregular often require pacemakers. Here we will take a look at what pacemakers are.
What is a Pacemaker?
A pacemaker (sometimes called an artificial pacemaker) is a small device that measures around 1.5 inches in length (see picture above) that sits in a small pocket underneath the skin near the heart. It is a metallic device to which is attached one or two wireless called leads. These leads are placed in the chambers of the heart and the pacemaker controls the rate and rhythm of the heartbeat.
In other words, an electronic pacemaker contains two main parts:
- Pulse generator – This is a small oval metallic device that generates electrical impulses that are transmitted to the heart.
- Leads or electrodes – These are flexible insulated wires that are attached to the pulse generator and are inserted into the heart chambers. Up to 3 wires may be attached to the pulse generator. Electricity from the pulse generator is transmitted through these wires into the heart and this in turn controls the rate at which the heartbeats.
When are Pacemakers Inserted?
Pacemakers are inserted when the heartbeat is either too slow or is irregular. The use of the pacemaker is to maintain a normal and a regular heart rhythm.
Before we discuss why pacemakers are inserted, it may be worthwhile reviewing how electricity is conducted through the heart.
Below are some of the common reasons why pacemakers will be inserted:
- A slow and irregular heart rhythm such as slow atrial fibrillation
- An irregular heart rhythm that results in episodes of collapse or near collapse
- An irregular, slow heart rhythm that follows a heart attack (such as heart block)
- Advanced heart failure accompanied by life-threatening irregular heart rhythms such as ventricular tachycardia (here the pacemaker is often a part of a treatment system called an implantable cardioverter defibrillator or ICD).
- Irregular or slow heart rhythms due to heart failure