Introduction
SCA is a condition where the mechanical action of the heart ceases. This condition leads to circulatory arrest and oxygen deficiency in organs. 
Objective
The aim of the study is an analysis of the relationship between the type of medical rescue actions taken and ROSC in children.
Material and method
The case-control study was based on the medical documentation of the Voivodeship Rescue Service in Katowice (VRS) of the years  2014-2015.  The results are presented by means of proportion and median. Non-parametric statistics (Pearson's chi-squared test and Mann-Whitney U test) were used to compare groups of patients. The value of statistical significance (p<0.05) was equal in all analyses. 
Results
There were 475 341 dispatches in the VRS in Katowice in the years 2014-2015. Among these interventions, 124 cases were related to SCA in patients under the age of 18 years (0.00026 %). SCA was more common in male (73 cases) than in female (51) patients (p<0.05). The patients were divided into three groups: individuals under the age of 1 year (31 cases), individuals aged between 1 and 8 years (58 cases), and individuals aged between 8 and 18 years (35 cases). The age median amounted to 5.75 years. The most common place of SCA incident was patient’s home (p<0.001). Non-hospital SCA was most frequent in the presence of a witness (p<0.001). Any type of medical rescue actions was taken in 92 cases (p<0.05). The most frequent action was chest compression (p<0.001). The first diagnosed heart rhythm types were asystole (65 cases) and ventricular fibrillation (16 cases). ROSC was successful in 41 cases (33.06%). The median of the time from dispatch to arrival in the highest priority code (C-1) was 6 min 19 sec, compared with 9 min 21 sec in the lower priority code (C-2; p<0.05). ROSC rate was higher in patients with ventricular fibrillation (VF) than in patients with non-shockable rhythm (VF: 62.5 % vs. asystole: 26.47%; p < 0.001). 
Conclusion
A successful resuscitation depends on the quality of medical rescue actions.

4 - Sudden cardiac arrest (SCA) in children: an analysis of medical rescue actions performed by the emergency medical teams of the Voivodeship Rescue Service in Katowice in the years 2014-2015