The EC-3H device records three independent ECG channels with high precision and detects pacemaker beats as well. The analysis program performs automatic QRS detection, classification, and rhythm analysis that can be interactively modified by the user. The analyzing program performs time and frequency based HRV, pacemaker, QT, AF and ST analysis of the 24 hours recordings. The transparency and the interpretation of the results are aided by the color coded graphs and tables. The decision criteria may be changed, the classified beats and event segments may be redefined. The quick and precise evaluation of the recordings is helped by the efficient decision making algorithms, the availability of a native language version and the option for the generation of simple summarizing reports make the system easy to use.