A Holter monitor is a portable device that continuously records the heart’s electrical activity, typically over 24 to 72 hours. It is an important diagnostic tool for detecting intermittent arrhythmias that may not be captured during a standard ECG.

Holter monitoring is commonly used to investigate symptoms such as palpitations, dizziness, or unexplained fainting. It can also assist in assessing heart rate variability, identifying abnormal rhythms, and monitoring the effectiveness of treatment or medications. The data collected is analysed by a cardiologist to detect clinically relevant rhythm disturbances and guide further management.