Heart Rate Monitoring in Implanted Pacemakers

Abstract

Increasing pacemaker memory allows integration of heart rate monitoring into the pacemaker. Two main methods can be distinguished. 1. Heart rate monitoring in histograms. 2. Heart rate monitoring in the time domain (heart rate holter). Method 1 is useful in antitachycardia and diagnostic pacemakers when short specific events must be detected (tachycadia, bradycardia). For the analysis of a rate adaptive pacemaker this method is less appropriate as it does not give any information about the dynamics of rate changes or its time relations. For this purpose Method 2 will give more information about the functioning of the pacemaker as it does not only store the heart rate but also the timing of the heart rate so that changes in heart rate can be correlated to the activity of the patient. An algorithm was developed to store the average heart rate over 7.8 minute periods in a pacemaker. On interrogation of the pacemaker the information will always reveal the heart rate over the 24 hours prior to interrogation. This monitor can also be temporarily programmed to store the average heart rate in 20 second intervals to monitor the response to an exercise test for a period of 1 hour. The time needed for a standard follow-up procedure of a rate adaptive pacemaker can be dramatically reduced to a value close to the follow-up time of a standard VVI pacemaker.

Pacemaker Stored Electrograms: Teaching Us What Is Really Going On in Our Patients

“…The first use of time-based diagnostics was to document the patient's heart rate. 4 Nowadays intrinsic, paced and sensor rates, sensing and pacing thresholds, and lead impedance data are available as time-based data. 5 Diagnostic histograms are used to provide information about sensed amplitudes, pacing rates, atrioventricular (AV) and ventriculoatrial (VA) intervals or mode switching episodes, and these data could be combined with detailed onset EGM recordings to provide a broader clinical perspective.…”

Pacemaker Memory Data Compared to Twenty‐Four‐Hour Holter Monitoring in Patients with VVI Pacemakers and Chronic Atrial Fibrillation

“…This method of data storage is much easier to achieve. A standard pacemaker is capable of storing all R‐R cycles of the heart rate counted over a period of many years 6–15 …”

“…However, the relatively short duration of this method is a disadvantage. Modern technology has introduced special heart rate monitoring algorithms into pacemaker devices, including some of the functions of traditional ambulatory Holter devices (pacemaker memory data [PMD]) 5–15 . Data regarding the mean and maximum heart rate as well as the number of episodes of rapid rate and the percentage of paced complexes may be stored in PMD and include a period of up to several months.…”