ECG examination belongs to basic procedures in the care of patients with heart failure. The Euroheart Survey study followed the data and therapy of hospitalized patients with chronic heart failure (CHF) with participation of 116 hospitals from 25 European countries and surveyed documentation of 45 993 patients dismissed from internal wards. A new atrial fibrillation or supraventricular tachycardia affected 25.3 % of patients, chronic fibrillation was encountered in 23 %. Bradyarrhythmia occurred in 10.8 % and pacemaker was applied in 8.5 % of patients. Ventricular arrhythmias were present in 8.4 %, implantable cardiovertor-defibrillator in 1.5 %. Syncope was reported in 15 % and the arrhythmic death was described in 1.83 %. The patients with heart failure suffer from a high incidence of ventricular arrhythmias. About 40 - 50 % of death events in patients with CHF are estimated to be associated with a sudden death or arrhythmia. Large clinical studies investigate the occurrence of and influence upon the sudden death as indices of therapy. The disorders of rhythm as well defects of ventricular conduction may be the risk factors of survival in patients with CHF. The Italian registry of heart failure includes examinations of 5 517 patients. A complete blockade of the left bundle branch block (LBBB) was present in 25.2 % patients, whereas a complete blockade of the right bundle branch block (RBBB) occurred in 6.1 %. The patients differed in the CHF cause: the group with LBBB suffered more frequently from dilatative cardiomyopathy, whereas IHD more present more frequently in patients without the blockade. The groups also differed in the severity of the disease. The patients with LBBB had a higher prevalence of heart weakness NYHA III and IV (32.8 % and 26.4 %, respectively, P < 0.001), lower systolic blood pressure, more frequent third heart sound (34.2 % versus 22.2 %, P < 0.001), cardiomegaly classified as a cardiothoracic index higher that 0.55 (63.2 % versus 55 %, P < 0.04). In the course of one-year observation 11.9% of patients died, death being evaluated as sudden in 46%. The one-year mortality in patients those with LBBB was 16.1 % in contrast to 10.5 % in those who had not suffered from the blockade. A sudden death affected 5.5 % of patients in the whole cohort, the frequency being again in LBBB (7.3 % vs. 4.9 %). The risk further increased with a simultaneous atrial fibrillation. After heart transplantation, ECG is also of importance for revealing an acute rejection. In the bilateral operation technique a direct alteration of the sinus node could be the cause of dysfunction. Various bradyarrhythmias developed in later periods of time. A modification of the operation technique has been used in the last 10 years. The application of bicaval method eliminated brachycardiac complications after heart transplantation. A cardiostimulator proved to be necessary in 5 to 15 % of patients when biatrial technique was used, whereas it was virtually not required with the bicaval technique. The blockade the left bundle branch block is an unfavorable prognostic factor in the same way as in CHF, whereas of the right bundle branch block is critical in the heart transplantation. It is supposed to be caused by surgical or thermal damage or it is also associated with different degree of the right ventricular dysfunction and a higher number of rejections. The blockade is also associated with worse one-year survival (74 % vs. 92 %, P < 0.03). Conclusion: ECG retains its position even in modern times not only in the diagnosis of conditions responsible for heart failure, in the diagnosis of disorder of rhythm and conduction, but it is also of prognostic value. It also retains its position in the same areas as in heart failure, i.e. in the diagnosis and prognosis in heart transplantation.

        Key words: ECG - Heart failure - Heart transplantation