What are the dangerous signs on Holter monitoring?

Holter monitoring is an ambulatory ECG monitoring, usually with a digital recorder, attached to a belt. ECG is the recording of electrical activity of the heart. Two or three channels are usually recorded with an appropriate number of patch electrodes attached to the chest. Holter monitoring is usually done when a heart rhythm abnormality is suspected.
Dangerous signs to look for on a Holter tracing are life threatening fast and slow heart rhythms. Here is a long pause which could cause giddiness or transient loss of consciousness. In this case the natural pacemaker of the heart known as sinus node, has stopped functioning for some time. This occurs in a disease known as sick sinus syndrome (SSS).