Standard rest electrocardiogram, Holter monitoring, and continuous electrocardiographic monitoring (including effort stress test). Normal electrocardiogram and alterations in the main cardiovascular diseases. Supraventricular and ventricular arrhythmias: pathophysiology, electrocardiographic pattern and clinical presentation. Disturbances of cardiac excitation and conduction (sinus node dysfunction, atrioventricular block, bundle branch blocks): electrocardiographic pattern and their clinical implications. Cardiac pacing: classification of the devices, their functions, implantation procedures, paced electrocardiogram