In the last two years 27 patients (mean age: 63.2 +/- 6.9 years) received Telectronics META MV pacemaker generators at the SZOTE. In 6 cases the generators were connected to atrial pacemaker electrodes, and in 21 cases to ventricular electrodes. To assess the characteristics of the rate responsive function exercise stress test was performed by 17 of these subjects. The authors give an account on the rate adaptive functions of these type pacemakers. The generator is an SSIR one. The rate responsive factor--i.e. the numerical characteristics of the pulse rate acceleration suggested by the pacemaker itself--was similar for atrial and ventricular electrodes.