New Method of Atrial and Ventricular Capture Detection

Polarization as a result of the pacing stimulus has always been the main factor for complicating evoked response detection. Tri‐phasic pulse schemes have been developed and used for a long time to solve the polarization issue and are used in commercial products today to enable evoked T‐wave detection. For measurement of the evoked R wave in the ventricle and the evoked P wave in the atrium a further optimization step had to be taken. The results presented in this paper show that by individual optimization of the lead system in all cases the evoked P‐ or R wave could be detected. One aspect of the tri‐phasic pulse scheme is the dynamic behavior of the polarization to a change in amplitude or pulse width of the pacing pulse. The time to rebalance the electrode tissue interface and the non‐linear behavior of this system can lead to incorrect detections of evoked potentials. The response time of this phenomenon was investigated. A possibility to solve this problem is described with the introduction of a double pulse scheme where a test pulse is placed in front of the regular output pulse. Changes in this double pulse balanced system never lead to a loss of capture situation and the system is given time to re‐balance before it can be decided which of the two pulses was responsible for a depolarization of the myocardium.