ObjectiveTo approach the value of diagnosis with the 256-slice spiral CT in severe tetralogy of Fallot of infant.MethodsFrom January 2008 to December 2010,48 cases (severe tetralogy of Fallot of infant) were examined with 256-slice spiral CT preoperatively.All cases were then analyzed in workspace with maximum intensity projection(MIP),multiplanar reconstruction(MPR) and volume rendering (VR),while compared with transthoracic echocardiography (TTE) and surgical results.Results CT examination found that TTE misdiagnosis 4 cases of patent ductus arteriosus and 6 cases of aortic coarctation.Meanwhile,CT showed 6 aorta pulmonary collateral arteries in 5 cases.In 48 cases,surgical results confirmed 47 cases by 256-shce spiral CT,while 33 cases by TTE.The diagnosis accuracy rate of 256-slice spiral CT and TTE was 97.9％ (47/48) and 68.8％ (33/48) respectively.There was statistically significant difference of the two inspections in diagnostic accuracy (P ＜ 0.05).ConclusionThe inspection of 256-slice spiral CT can benefit the preoperative diagnosis and operation program in severe tetralogy of Fallot of infant.

Objective To study the correlation between radial artery graft patency and the degree of native coronary stenosis in coronary artery bypass grafting. Methods The clinical data of 290 patients who had underwent off-pump coronary artery bypass grafting were retrospectively analyzed. The left internal mammary artery, radial artery and saphenous veins were as grafts. The patients were divided into 3 groups according to the stenosis of right coronary artery before operation:group Ⅰ(right coronary artery stenosis 50%-75%, 85 cases), groupⅡ(right coronary artery stenosis 76%-89%, 95 cases) and group Ⅲ (right coronary artery stenosis 90%-100%, 110 cases). The patients were followed up for 2 to 5 years, and the graft patency was assessed using CT coronary angiography. Results There was no death and serious complications in 3 groups. Among the 3 groups, the total graft patency rate of left internal mammary artery grafts was 93.3% (270/290), the total graft patency rate of saphenous veins grafts was 70.2%(433/617), and the total graft patency rate of radial artery grafts was 69.7%(202/290). There was no statistical difference in the graft patency rate of radial artery grafts between group Ⅱ and group Ⅰ(P>0.05). The graft patency rate of radial artery grafts in group Ⅲwas significantly higher than that in groupⅡand group Ⅰ:85.5%(94/110) vs. 68.4%(65/95) and 50.6%(43/85), and there was statistical difference (P<0.05). The graft patency rate of radial artery grafts was significantly higher than the graft patency rate of saphenous veins grafts in group Ⅲ :85.5%(94/110) vs. 71.5%(168/235), and there was statistical difference (P<0.05). There were no statistical differences in the graft patency rates of left internal mammary artery grafts and saphenous veins grafts among 3 group (P>0.05). Conclusions The correlation between radial artery graft patency and the degree of native coronary stenosis is significant in coronary artery bypass grafting. Patients with severe proximal right coronary artery stenosis (≥90%) may have better patency rates at mid-term follow up after using radial artery grafts.

Objective To analyze the reasons and treatment methods of high transprothetic pressure gradient after aortic valve replacement. Methods The clinical data of 45 patients with high transprothetic pressure gradient after aortic valve replacement were retrospectively analyzed. The patients were followed up for average 24.6 (12 - 40) months. The postoperative effective orifice area (EOA) of artificial valve was measured by transthoracic color Doppler ultrasound. Compared with published referred EOA of different artificial valve, there were 2 kinds results:measured EOA=referred EOA and measured EOA0.85 cm2/m2 and EOAI<0.85 cm2/m2. The reasons of high transprothetic pressure gradient were analyzed according to the above different standard. Results In the 45 patients with high transprothetic pressure gradient after aortic valve replacement, prosthesis-patient mismatch (PPM) was in 33 cases, and prosthetic dysfunction was in 10 cases, among whom 5 cases were because of thrombus (3 cases improved after increasing the dosage of warfarin, 2 cases underwent re-aortic valve replacement), 3 cases were because of severe bioprosthetic calcification (underwent re-aortic valve replacement), and 2 cases were because of prosthetic ring pannus and influenced movement of the leaflets (underwent re-aortic valve replacement). High flow in the left ventricular outflow tract occurred in 2 cases. The patients had no obvious discomfort, and did not receive special treatment. Four cases died, among whom 2 cases were because of severe PPM, and the other 2 cases were because of noncardiac. Conclusions Many reasons can result to the high transprothetic pressure gradient, and the PMM is the most common reason. Choosing the right treatment plan can improve the survival rate of patients.

BACKGROUND:With the development of biomechanics,its research into cardiovascular diseases has become more and more extensive.By studying the mechanical properties of blood vessels,the pathogenesis of cardiovascular diseases such as atherosclerosis and restenosis can be effectively revealed and new ideas and methods can be developed for the treatment of cardiovascular diseases. OBJECTIVE:To review the research status of apoptosis of vascular smooth muscle cells induced by mechanical stress and search for potential target molecules and signaling pathways for clinical treatment,thereby improving the clinical treatment effect on cardiovascular diseases such as atherosclerosis and restenosis. METHODS:We searched the literature in CNKI,PubMed and ScienceDirect databases from January 1992 to May 2023.The search terms were"vascular smooth muscle cell,mechanical stress,shear stress,stretch stress,apoptosis"in Chinese and English.Finally,63 articles were included for review and analysis. RESULTS AND CONCLUSION:Physiological and pathological apoptosis of vascular smooth muscle cells is an adaptive remodeling in response to the changes in vascular mechanics.Vascular smooth muscle cells in different parts have different mechanical stimuli and their pathogenesis is also different.Low shear stress,physiological shear stress and high shear stress directly interact with surface molecules,receptors and proteins of vascular smooth muscle cells to regulate apoptosis-related signaling molecules and inhibit cell proliferation,thus regulating the apoptosis of vascular smooth muscle cells.In this part,the research on promoting proliferation is not summarized.Low stretch stress,physiological stretch stress and high stretch stress can all cause apoptosis of vascular smooth muscle cells,but it is still controversial.There are many mechanoreceptors(such as integrins and receptor tyrosine kinases)on the surface of vascular smooth muscle cells,which can transform mechanical signals into intracellular chemical signals(such as the Hippo pathway),activate the apoptosis signals of vascular smooth muscle cells and regulate the apoptosis of vascular smooth muscle cells.In short,different mechanical stimuli start a variety of signal pathways and regulate the apoptosis of vascular smooth muscle cells through various signal molecules.For example,shear stress affects Fas/FasL and Akt pathways mainly by stimulating prostaglandin secretion and transforming growth factors.Strech stress mainly regulates the YAP pathway and Notch pathway through Yes-related proteins.At different times or intensities,these molecules may play opposite two-way roles.For example,when mouse vascular smooth muscle cells are stretched at 10%physiological tension for 1 hour,cell proliferation increases.However,the proliferation of human vascular smooth muscle cells can decrease after 12 hours of stretching.Clinically,the key molecules of mechanical transduction can be disturbed by searching for key molecules that interfere with mechanical transduction at their critical time points of action.