CRT-P devices features and algorithms

The goal of rate adaptive pacing is to provide an increase in heart rate via an increase in cardiac pacing in response to metabolic needs: this would include during periods of exercise, but also during disease states and emotional reactions. The dual sensor technology is a combination of an accelerometer and minute ventilation for efficient rate response to chronotropic incompetence. It has been designed to blend information from accelerometer and minute ventilation sensors for a more physiologic rate response.

Rest Rate is related to rate adaptive pacing. While rate adaptive pacing increases the pacing rate to address patient demands, the rest rate algorithm uses similar data to slow the pacing rate below the programmed basic rate. In this manner, it can reproduce circadian variations without the constraint of being set by a clock schedule. In addition, rest rate has the added benefits of potentially reducing percent pacing and therefore extending battery life, and may offer patients a more physiological pacing rate.

With the Sleep Apnea Monitoring (SAM) function, MicroPort pacemakers provide the physician with automatic screening of pacemaker patients for the risk of severe Sleep Apnea. SAM has been designed to detect, count and report abnormal breathing events during the night. These events are detected using the minute ventilation signal. This allows the calculation of respiratory disturbances over the last six months, representing sleep disordered breathing events at night.

The WARAD is designed to monitor the atrial activity in order to discriminate pathological atrial waves (Atrial Fibrillation, Atrial Flutter, Atrial Tachycardias) from sinus P waves. This atrial discriminator uses atrial prematurity to trigger mode switching. Refer also to the Fallback Mode Switch Tech Corner article for more details on the Fallback Mode Switch algorithm.

The FMS function is designed to diagnose atrial arrhythmias and manage their occurrence using the WARAD (Window of Atrial Rate Acceleration Detection): in the event of atrial arrhythmia, FMS switches from DDD(R), SafeR™(R) or Dplus(R) pacing mode to an inhibited dual- chamber pacing mode DDI(R) to avoid prolonged ventricular pacing at a high rate for the entire duration of the sustained atrial arrhythmia.

The Anti-PMT algorithm is intended to protect the patient from Pacemaker-Mediated Tachycardia (PMT) without reducing the atrial sensing capability of the device.