Spontaneous Microbubbles Associated With Prosthetic Mitral Valves As Assessed By Transesophageal Echocardiography and Its Clinical Importance

There is in sufficient information about the incidence, mechanism and clinical importance of spontaneous microbubbles (SMB) associated with prosthetic valves observed by echocardiography. The aim of our study was to investigate the incidence of SMs associated with prosthetic mitral valves and related clinical features and echocardiographic parameters. One-hundred and ninety-eight patients with prosthetic mitral valves (mean age 37.9 ± 13.3 years) evaluated by transesophageal echocardiography (TEE) were included in the study and age, gender, cardiac rhythm, prosthetic valve type, area and gradients, left atrial diameters and flow velocities, incidence of mitral valve thrombosis, paravalvular leakage, Jeft atrial spontaneous echocentrast (LA-SEC), and systemic arterial embolism (SAE) were compared between groups with and without SMB. The incidence of SMB, 50.5 % in the entire group, was 82.7 %, 38.3 % in the bileaflet and monoleaflet mechanical valve subgroups, respectively (p<0.05). But no SMB was observed in bioprosthetic valve subgroups. No significant difference existed in the age, rhythm, transvalvular gradients, mitral valve area, left atrial diameter, atrial forward and backward mean velocities, incidence of paravalvular mitral leakage, LA-SEC, and SAE between the groups with and without SMB (p>0.05). We conclude that SMB is significantly associated with the type of the prosthetic valve (bileaflet over monoleaflet and bioprosthetic valves) and is cansidered to be a clinically innocent echocardiographic finding.