Sensors for rate‐adaptive pacing: How they work, strengths, and limitations

Abstract

Chronotropic incompetence is the inability of the sinus node to increase heart rate commensurate with increased metabolic demand. Cardiac pacing alone may be insufficient to address exercise intolerance, fatigue, dyspnea on exertion, and other symptoms of chronotropic incompetence. Rate‐responsive (adaptive) pacing employs sensors to detect physical or physiological indices and mimic the response of the normal sinus node. This review describes the development, strengths, and limitations of a variety of sensors that have been employed to address chronotropic incompetence. A mini‐tutorial on programming rate‐adaptive parameters is included along with emphasis that patients' lifestyles and underlying medical conditions require careful consideration. In addition, special sensor applications used to respond prophylactically to physiologic signals are detailed and an in‐depth discussion of sensors as a potential aid in heart failure management is provided.

Atrial pacing above the lower rate limit: What is the cause?

“…Most commonly, sensor-driven pacing is a result of accelerometer activation during exercise. 1 This typically does not lead to an abrupt change in the pacing rate, which was the case in this patient. Rate response pacing may also alter the AV interval (AVI) if "dynamic" AV delay is programmed.…”

“…The most common cause of atrial pacing above the LRL is sensor‐driven pacing. Most commonly, sensor‐driven pacing is a result of accelerometer activation during exercise 1 . This typically does not lead to an abrupt change in the pacing rate, which was the case in this patient.…”

Cardiac implantable devices during exercise: Normal function and troubleshooting

“…In patients requiring cardiac pacing due to sinus dysfunction or chronotropic incompetence, the "rate response" feature, mediated by activity, body temperature or myocardial impedance sensors should be programmed; 4,5 as well as an “upper rate limit”; and for the majority, “hysteresis of the atrioventricular (AV) interval” function is also turned on, in order to avoid unnecessary ventricular pacing 6‐8 and maintain most of the time an AAI functional mode of stimulation (Figure 1A). The maximum stimulation rate, as well as the slope, both acceleration and deceleration, are chosen empirically, according to age; then, they are tested by monitoring the performance of the device during exercise 9,10 …”

Advances in Cardiac Pacing: Arrhythmia Prediction, Prevention and Control Strategies

“…Technological advances in pacing have enabled rate responsive or adaptive pacing which successfully tackle chronotropic incompetence wherein the sino-atrial node is unable to increase the heart rate to meet the changing metabolic demands (Trohman et al, 2004(Trohman et al, , 2020. Most modern devices with adaptive pacing have sensors to detect physiological or physical indices of activity and simulate normal sino-atrial nodal response (Trohman et al, 2004(Trohman et al, , 2020).…”

“…Technological advances in pacing have enabled rate responsive or adaptive pacing which successfully tackle chronotropic incompetence wherein the sino-atrial node is unable to increase the heart rate to meet the changing metabolic demands (Trohman et al, 2004(Trohman et al, , 2020. Most modern devices with adaptive pacing have sensors to detect physiological or physical indices of activity and simulate normal sino-atrial nodal response (Trohman et al, 2004(Trohman et al, , 2020). Yet, despite the advances in cardiac arrhythmia treatment modalities, given the spatiotemporal and structural complexity of the human heart, designing algorithms to effectively control the heart rate and prevent fatal rhythms has been challenging.…”