In vitro study, normal cardiac prosthetic valve has functional regurgitation due to structural characteristics of prosthetic valve. To evaluate functional regurgitant characteristics of prosthetic valves, we examined patients who had clinically normal mitral prosthesis.

Transesophageal two-dimensional and color doppler echocardiography were performed to 25 patients who had the clinically normal mitral prosthesis.

Seven patients had the mitral bioprosthesis and 18 patients had the mitral mechanical prosthesis. Regurgitation was found in 4 patients(57%) with bioprosthetic valve, and the pattern of regurgitation was central in three patients and unilateral in one patient. But regurgitation was detected in 17 patients(94%) with mechanical prosthesis, and the pattern of regurgitation was bilateral in twelve patients, unilateral in four patients and central in one patient(p=0.0035). The length of regurgitant jets were 22.00±6.73(mm) in bioprosthetic valve and 28.65±7.33(mm) in mechanical valve. The regurgitant jets were detected in systolic period in most of patients. But in 4 patients who had tachycardia during TEE, regurgitation was detected in systolic and early diastolic period.

Regurgitation was found in clinically normal cardiac prosthetic valves by TEE. These findings may be useful to differentiate between normal and abnormal cardiac prosthesis.