Spontaneous echocardiographic contrast is a manifestation of SLUDGE syndrome in the cavities of the heart. The factors that contribute to the emergence of this phenomenon are atrial fibrillation, mitral stenosis, mitral valve prosthesis, left atrial dilatation, decreased left ventricular ejection fraction, hypercoagulable blood conditions, inflammatory diseases, dyslipidemia. Spontaneous echo contrast is a prothrombogenic condition and increases the risk of thromboembolic events, including cerebrovascular complications. This article presents an analytical review of literary sources on this phenomenon for the purpose of its study and determination of treatment tactics in each clinical case.