[The "flickering" phenomenon in the right atrium]

To specify characteristics and reasons of flickering in the right auricle (FRA) detected at two-dimensional ECG, 278 patients with innocent cardiac murmur (ICM) and 93 patients with congenital heart disease (CHD) underwent clinical and ECG examinations. FRA was found in 34.5% of ICM and 57.0% of CHD patients. Topographic-anatomical, ECG, intraoperative comparative investigations suggested that FRA may result from the eustachian valve movements and fenestration-filament structure of the endocardium at the opening of the inferior vena cava, interatrial septum, coronary sinus valve, base of the atrioventricular cusps. The movement of the eustachian valve was followed through the cardiac cycle. It is thought advisable that FRA characteristics should be taken into consideration for valid understanding of right atrial circulation in normal and CHD conditions.