[Doppler echocardiographic assessment of CarboMedics prosthesis in patients with mitral valve replacement].

OBJECTIVE: To evaluate the CarboMedics (CM) prosthesis function two years after mitral valve replacement, and to compare the effective orifice area (EOA) calculated by pressure half-time (PHT) method and continuity method (CON). METHODS: Forty nine patients who underwent isolated mitral valve replacement with a CM prosthesis were recruited in this study, which included 13 cases of 25 mm CM prosthesis and 36 cases of 27 mm CM prosthesis. Two years after the mitral valve replacement, transthoracic echocardiography (TTE) was performed, measuring left ventricular ejection fraction (LVEF), stroke volume mean gradient (SV), PHT, peak early mitral diastolic velocity (E velocity), mean gradient (MG), time-velocity integral of left ventricular outflow tract/time-velocity integral of mitral valve prosthesis (TVI(MVP)/TVI(LVOT)). The function of the prosthetic valve was considered normal when PHT < 130 ms, E velocity < 2.0 m/s and TVI(MVP)/TVI(LVOT) < 2.2. RESULTS: More than half (53.1%) of the patients had normal function of the prosthetic valve. No significant differences were found in PHT, MG, TVI(MVP)/TVI(LVOT), EOA or IEOA between the patients with 25 mm valve and the patients with 27 mm valve (P > 0.05). But the patients with 25 mm valve had higher E velocity than the patients with 27 mm valve (P < 0.05). The PHT method produced greater EOA than by the CON method (P < 0.05). CONCLUSION: The function of CM prosthesis is acceptable two years after the mitral valve replacement, with most patients having PHT < 130 ms, E velocity < 2.0 m/s and TVI(MVP)/TVI(LVOT) < 2.2. PHT method produces greater EOA than CON method.

[Study on levels of angiotensin converting enzyme and C-reactive protein in peripheral blood of mitral valve replacement preoperative patients with atrial fibrillation].

OBJECTIVE: To evaluate the levels of angiotensin converting enzyme and C-reactive protein in the peripheral blood of mitral valve replacement preoperative patients with atrial fibrillation (AF). METHODS: 24 atrial fibrillation patients, who were hospitalized for mitral valve replacement surgery, as study group (AF group) and 23 sinus rhythm patients as control group (SR group) were included in this study. The angiotensin converting enzyme and C-reactive protein in peripheral blood were quantified and compared in an attempt to find out whether the significant difference existed between the AF and SR groups. All patients undertook ultrasonic cardiography before operation. RESULTS: There was no significant difference in C-reactive protein between two groups (P > 0.05). The quantity of angiotensin converting enzyme in patients with AF was higher than that in patients with SR, which was statistically significant (P < 0.05). And also the left atrial dimension had a linear correlation with angiotensin converting enzyme. The obvious relation between angiotensin converting enzyme and left atrial dimension was seen in AF patients who need mitral valve replacement. CONCLUSIONS: This study demonstrates that the increase of the quantity of angiotensin converting enzyme in peripheral blood has relationship with atrial fibrillation of patients who need mitral valve replacement, and more research on the relations between AF and angiotensin converting enzyme would be needed.

[Tricuspid valve replacement and anticoagulation therapy: a report of 70 cases].

OBJECTIVE: To evaluate the operative indication, the choice of valve prostheses, and the method of anticoagulation therapy of tricuspid valve replacement (TVR). METHODS: From May 1998 to January 2008, 70 patients underwent TVR. There were 59 cases of rheumatic heart diseases. The operations included mitral and tricuspid valve replacement for 37 cases, triple valve replacement for 18 cases, isolated TVR for 13 cases, and tricuspid and aortic valve replacement for 2 cases. All the patients received oral anticoagulant therapy (warfarin) 2 d after the operations. RESULTS: There were 3 in-hospital deaths (4.3%) and 1 late death (0.4%). The follow-up rate was 88.1%, and the cumulative follow-up was 243.5 patient-years (pty). The anticoagulation-related event rate was 2.9% pty, and the mean INR value of 643 out-patient samples was 1.87 +/- 0.68. Post-operative heart function NYHA classification: 52 cases in class I to II, and 7 cases in class III. CONCLUSIONS: TVR should be indicated for severely damaged and deformed tricuspid valve of rheumatic heart diseases. Bileaflet mechanical valve is a suitable prosthesis for TVR. The optimal anticoagulation therapy intensity of TVR needs to be investigated.

[Impact of cardiopulmonary bypass on free amino acid spectrum in plasma for patients with prosthetic valve replacement during the perioperative period].

OBJECTIVE: To investigate the impact of cardiopulmonary bypass (CPB) on free amino acid spectrum in plasma for patients with prosthetic valve replacement. METHODS: The concentrations of the free amino acid in plasma for 22 patients with prosthetic valve replacement were measured with pre-column derivatization of high-performance liquid chromatography. RESULTS: Compared with the preoperative data, the concentrations of some free amino acid in plasma decreased after the operation of cardiopulmonary bypass (CPB), especially some of the glucogenic amino acid and branch chain amino acid decreased significantly (P<0.05). CONCLUSION: The operation of cardiopulmonary bypass (CPB) can decrease the concentrations of some free amino acid in plasma for patients with prosthetic valve replacement. It is essential to give these patients proper nutrition support during perioperative period.