ICD therapy has undergone remarkable transformation in 25 years since the device was approved for human use. Modern devices provide detailed information on frequency and morphology of electrocardiographic signals before, during and after therapy. The simplicity of the defibrillator implantation is now approaching the pacemaker, reducing the pulse generator and improving drain design and waveform shapes. Despite the improvement of diagnostic capabilities and reduction in size, the device's longevity is now> 6 years. Further advancement in drain technology and algorithms of arrhythmia discrimination should increase the efficiency and reliability of the therapy. Ultimately, the device has the ability to treat multiple problems in addition to life-threatening ventricular arrhythmia, atrial arrhythmia and CHF. In this study we retrospectively evaluated the patients whose device was built in the period from 1.1.2013-1.1.2019. year at the Department of Cardiology KB Merkur. The study included a total of 91 patients, 11 (12%) women, and 80 males (88%). The aim of this study was to compare the activation of ICD/CRT-D devices compared to the clinical parameters we chose as essential. The clinical parameters we chose have covered the etiology of the disease, the comorbidities that are essential and the medication therapy. Clinical parameters were in turn: ICM, NICM, AH, HLP, DM, ASK, statins, β-blockers, amiodarone, sakubitril/valsartan, spironolactone/eplerenone and ARB/ACI. These parameters were selected because of their expected effect on the activation of the device resulting from their either proarrhythmic or antiarrhythmic effect. We did not get a statistically significant value by processing data obtained for each variable. The results of this research should be taken with the reserve due to a small sample of patients, further involvement of patients with which the device will be installed in the following years in KB Merkur can't rule out a different outcome of the extended research.