The Holter is a recording device that comes in two different forms: a small portable tape recorder (like a walkman), or a small digital device the shape of a pager. You wear the device on a belt round your waist. Four or six ECG leads from the device are taped to your chest. The device records the electrical activity of your heart for 24 to 48 hours, or for up to 7 days if a digital one is used. The doctor can then analyse the electrical activity and rhythm of your heart to find out if you have any arrhythmias (for example, the arrhythmias typical of LQTS and CPVT), or some of the other features characteristic of LQTS.
Figure 7: Holter
The Holter monitor is attached by 4 or 6 electrical leads to your body. It monitors your heart’s electrical activity over a period of time.