EVALUATION OF A DUAL SENSOR RATE-RESPONSIVE PACING SYSTEM BASED ON A NEW CONCEPT

The minute ventilation is known to be one of the most physiological in dicators of exercise. A curvilinear relationship between VE and the no rmal sinus rhythm (NSR) has been demonstrated in healthy patients. The aim of this study is to show that a pacemaker based on a VE sensor ca n reproduce such a relationship. Eighty-one patients received a Talent DR 213 (ELA Medical, Montrouge, France) pacemaker with a third-genera tion rate responsive algorithm. At 1-month follow-up, the patients und erwent a treadmill exercise test, after which three groups were-define d: group 1 had 6 patients who were 100% paced throughout the exercise test; group 2 had 10 patients who maintained NSR throughout the test; and group 3 had 12 patients who had cardiopulmonary recording during t he exercise test. In group 2 patients, the simulation function compute d the simulated rate (sim-rate), which was compared to the sensor-driv en rate (SDR). In group a:patients, sim-rate was compared to the NSR. In group 3 patients, cardiac and metabolic reserves were compared to d etermine the appropriateness of the rate response to exercise (HRR% vs MR%). The results showed that the mean correlation coefficient betwee n sim-rate and SDR was 0.983 +/- 0.005 (P < 0.001); the mean correlati on coefficient between NSR and SDR was 0.92 +/- 0.07 (P < 0.001); and a linear relationship was found between HRR% and MR%, with a mean slop e of 1.1 +/- 0.2 that was significantly equal to the theoretical value of 1 (P = NS). In conclusion, combining an activity-driven sensor wit h a physiological sensor allows the preservation of a;physiological ra te response during exercise.