Which of the following is a key feature of digital Holter monitors?

Digital Holter monitors are specifically designed to continuously record heart activity over an extended period, usually 24 to 48 hours. This continuous monitoring is crucial for capturing transient cardiac events that may not occur during a standard, short-term electrocardiogram (ECG). By providing a continuous stream of data, clinicians can identify arrhythmias or other heart conditions that might happen infrequently or during certain activities throughout the day and night.

The other options do not accurately reflect the characteristics or intended use of digital Holter monitors. For instance, the notion that they can only be used once is misleading, as they are reusable devices designed to be utilized for various patients over time, although the individual electrodes and leads may be single-use. Additionally, the design of modern digital Holter monitors has significantly improved, making them more compact and user-friendly when compared to older models, thus challenging the idea that they are bulky and inconvenient. Lastly, the statement that they are primarily used for lung function tests is inaccurate because Holter monitors are specifically intended for cardiac monitoring, not respiratory assessments.