ECG Workstation: Multi-Day ECG vs Holter

In routine clinical practice, Holter (aka 24-hour) ECG monitoring is widely used. Yet, what are the advantages of multi-day ECG monitoring over Holter monitoring? Let’s figure it out!

The Purpose

The need for long-term ECG monitoring is primarily due to the presence of rare (1-2 times per week or less) arrhythmic events or clinically significant symptoms (fainting or paroxysmal palpitations) in some patients. The Holter monitoring method won’t be able to capture these events. The longer the observation time, the more precise picture is formed. 

What are the differences? 

• Recorder. This refers to the device that the patient always carries during examination. The size of the recorder for multi-day ECG monitoring is close to a matchbox, and its weight is less than 30 grams. This allows wearing it for a long time without problems. Unlike the Holter recorder with its many wires, the long-term ECG monitoring recorder has only one cable and attaches to the front of the chest. 
• Data Transmission Method. In Holter monitoring, data is only transmitted after the study ends and the recorder is removed from the patient. With multi-day ECG telemonitoring, data transmission occurs parallel to the examination using wireless protocols. So the doctor can track the patient’s condition almost in real-time and give recommendations. 
• Number of Leads. Some attentive readers will ask: “What’s the significance of the number of leads in the recorder?” Simply put, leads are the number of “sticky pads” with wires connected to the recorder. The fewer there are, the easier it is to wear the device. However, it’s precisely the presence of 12 leads (as in standard ECG) that allows comparing these studies and, most importantly, more accurately detecting ischemia and determining the location of ventricular arrhythmias. This feature gives the method an advantage over loop ECG recorders (a device implanted under the skin for long-term ECG recording).

QT Interval

The QT interval on an electrocardiogram is as vital an indicator of human body function as pulse rate or respiratory rate. Unfortunately, we cannot measure it ourselves, even using “smart watches.” Its duration is inversely related to heart rate, which is why for convenience and comparison, a “corrected QT” is calculated. Both prolongation and shortening of this interval are dangerous, as they can become prerequisites for developing dangerous arrhythmias. It is the long-term ECG monitoring method that allows obtaining not only a detailed assessment of the interval duration throughout the observation period but also additional calculated parameters (QT dynamics).

References

Baquero, G. A., Banchs, J. E., Ahmed, S., Naccarelli, G. V., & Luck, J. C. (2015). Surface 12 lead electrocardiogram recordings using smart phone technology. Journal of electrocardiology, 48(1), 1-7.

Beers, L., van Adrichem, L. P., Himmelreich, J. C., Karregat, E. P., de Jong, J. S., Postema, P. G., … & Harskamp, R. E. (2021). Manual QT interval measurement with a smartphone-operated single-lead ECG versus 12-lead ECG: a within-patient diagnostic validation study in primary care. BMJ open, 11(11), e055072.

Hadzievski, L., Bojovic, B., Vukˇcevic, V., Beliˇcev, P., Pavlovic, S., Vasiljevic-Pokrajˇcic, Z., & Ostojic, M. (2004). A novel mobile transtelephonic system with synthesized 12-lead ECG. IEEE transactions on information technology in biomedicine, 8(4), 428-438.