Final answer:
A Holter monitor usually has either 3 or 5 leads, which are used to continuously record the heart’s electrical activity for diagnostic purposes over a 24-hour period. These devices are less comprehensive than a standard 12-lead ECG, which uses 10 electrodes, but are designed for ambulatory use and patient convenience.
Step-by-step explanation:
A Holter monitor is a type of portable electrocardiogram (ECG) device used for continuous monitoring of heart electrical activity over a prolonged period, typically 24 hours. The number of leads a Holter monitor has can vary, providing different levels of information.
While a standard ECG can use 3, 5, or 12 leads, for a Holter monitor, it typically uses fewer than a standard 12-lead ECG. Therefore, the most common configurations for Holter monitors are 3 or 5 leads. These leads are carefully placed on the patient’s body to continuously record the heart’s electrical activity as they go about their daily routine.
The term 'lead' in this context usually refers to the representation of the voltage difference between electrodes placed on the skin. Each lead provides a unique perspective on the heart’s electrical activity, which is crucial for diagnosing various heart conditions. The 12-lead ECG, used for more comprehensive testing, employs 10 electrodes with six positioned on the chest and four on the limbs. However, this level of detail is typically not required for the Holter monitor's purposes. The ambulatory nature of Holter monitors makes them less cumbersome and more practical for patients to wear while engaging in their regular activities.