Resting Electrocardiogram (ECG)
This is usually done at the time of your initial consultation with your cardiologist. However, patients can be referred by their GP for a resting ECG alone.
This simple and painless test takes about 5 minutes to perform.
The test measures the electrical activity of the heart. In the normal heart, electrical impulses are spontaneously generated in a structure called the sinus node, which is the heart’s natural pacemaker. The impulses spread through the heart in specialised tissue (conduction tissue), and this electrical impulse causes all the heart cells to contract. It is the coordinated contraction of the heart cells that leads to the heart’s pumping activity.
The test is performed by placing a number of electrodes, which are connected to an ECG machine, on the chest and limbs. The patient lies comfortably on a couch while the ECG trace is recorded.
An ECG provides information about heart rate and rhythm, and can also provide information about the presence of coronary artery narrowings, whether a heart attack has previously occurred, or even whether the heart is thickened or enlarged.
It is important to note that an abnormal resting ECG is very helpful in diagnosing heart disease, but a normal resting ECG does not exclude heart disease, and this is why other testing, such as an exercise ECG (or exercise stress test) is often needed as well (see next section).