Objective To investigate the effect of cardioplegia solution of autologous blood treated with ultraviolet irradiation and oxygenation (UBIO) on myocardial mitochondrion in mongrel dogs underwent open heart surgery under cardiopulmonary bypass (CPB).Methods Twenty male mongrel dogs were randomly divided into a control group and a UBIO group, 10 dogs in each group.The UBIO group was infused with UBIO blood as the cardiac arresting solution via the ascending aorta, while the control group was given the same treatment except that the cardiac arresting solution was blood cardioplegia.Blood samples were taken from coronary venous sinus before cross-clamping and after aorta declamping to measure the levels of cardiac troponin I (cTnI) and creatinine kinase MB isozyme (CK-MB).For both groups, right atrial myocardial tissue samples were taken to detect the activity of myocardial mitochondrion superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) , and concentrations of malondialdehyde (MDA) when the right atrium was opened and closed.Results In both groups, the average levels of SOD and GSH-PX were decreased during CPB, and the decrease of SOD and GSH-PX were to a significantly larger extent in UBIO group (P ＜ 0.05).The concentrations of cTnI, CK-MB, and MDA in the control group were increased significantly higher than those in the UBIO group (P ＜ 0.05).Conclusion The attenuated lipid peroxidation of myocardial mitochondria plays an important role in myocardial protection by UBIO as cardioplegia solution in open heart surgery under CPB.

Objective To investigate the effects of levocarnitine used as an ingredient of cardioplegic solution on cardiomyocyte apoptosis in patients undergoing heart valve replacement under cardiopulmonary bypass (CPB) .Methods Twenty-four NYHA grade Ⅱ or Ⅲ patients of both sexes (16 males, 8 females) aged 27-67 yrs undergoing heart valve replacement under CPB were randomly allocated into 2 groups (n = 12): levocarnitine group and control group. In levocarnitine group levocarnitine 6 g was added to 1 000 ml of 4℃ St Thomas Ⅱ cardioplegic solution, while in control group equal volume of normal saline was added instead of levocarnitine. Cardioplegic solution 15 ml?kg-1 was injected to perfuse the heart every 30 min during aortic cross-clamping. The KC1 concentration of the cardioplegic solution was reduced by half for the last injection. During CPB the naso pharyngeal temperature was maintained at 25-27℃. Cardiac index (CI) and left ventricular ejection fraction (LVEF) were measured 1 day before and 7 days after operation using heart color ultrasonography. A small piece of myocardial tissue was obtained from right atrium for assessment of apoptosis using terminal deoxynueleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) . The expression of Bax and Bcl-2 in cardiomyocytes was determined by immuno-histochemistry, and Bcl-2/Bax ratio was calculated. Results The rate of restoration of spontaneous heart beat after aortic unclamping was significantly higher in levocarnitine group than in control group (86.6% vs 47.3%) (P

Objective To investigate the effect of L-carnitine (LCN) on heart function following myocardial contusion in mongrel dogs.Methods Twenty-four male mongrel dogs were randomly divided into myocardial contusion group,low dose LCN group (LCN1 group),and high dose LCN group (LCN2 group) with 8 dogs per group,according to the random number table.The model of myocardial contusion was established in all groups.LCN1 and LCN2 groups were respectively treated with 100 mg/kg and 200 mg/kg LCN for three consecutive days before the injury and afterward.Left ventricular systolic pressure (LVSP),left ventricular end diastolic pressure (LVEDP),left ventricular ± dp/dt were recorded 30 min before injury,and 30 min,1 h,2 h,4 h as well as 6 h after injury.Blood samples were withdrawn from femoral vein to detect the levels of creatine kinase isozyme (CK-MB),cardiac troponin I (cTnI),and malondialdehyde (MDA).Wall motion score index (WMSI) was observed using the ultrasound examination 1 day before and 5 hours after injury.Myocardial tissue was available at 6 hours after injury for the examination of content of adenosine triphosphate (ATP).Results LVSP and ± dp/dtmax appeared a downward trend after injury,while a gradual increase in LVEDP.And the changes were relatively smaller with LCN intervention,especially in LCN2 group.Levels of CK-MB,cTnI and MDA increased after injury,but the same time point showed lower levels in LCN groups (especially in LCN2 group) as compared to myocardial contusion group (P ＜ 0.05).WMSI increased 5 hours after the injury,but the increase was higher in myocardial contusion group (2.46 ±0.31) than that in LCN1 group (1.91 ± 0.23) and LCN2 group (1.85 ± 0.25) (P ＜ 0.05).There was no significant difference in WMSI between the two LCN groups (P ＞ 0.05).Level of ATP in myocardial contusion group was (11.3 ± 1.6) μg/g,which was improved after LCN intervention (P ＜ 0.05),and the improvement was much higherin LCN2 group than in LCN1 group[(21.3±3.9) ug/g vs (15.7±2.8)ug/g] (P＜0.05).Conclusion LCN can alleviate the adverse effect of myocardial contusion on cardiac function in mongrel dogs,which may be associated with the reduced energy imbalance induced by LCN.

BACKGROUND: Animal experiments demonstrated that adding ultraviolet blood irradiation and oxygenation (UBIO) in cardioplegic solutions has myocardial protection during cardiopulmonary bypass (CPB).OBJECTIVE: To investigate the myocardial protective effect of UBIO as cardiac arresting solution in the process of CPB in old patients undergoing valve replacement.DESIGN, TIME AND SETTING: The randomized controlled trial of biochemistry level was performed at Department of Cardiac Surgery, Guizhou Provincial People's Hospital, from October 2006 to April 2008.PARTICIPANTS: A total of 46 old patients scheduled for heart valve replacement were randomly divided into test group and control group, with 23 patients in each group.METHODS: The test group was infuoed with the UBIO blood as a cardiac arresting solution via the ascending aorta. The UBIO blood accumulated from the subclavian vein (10 mL/kg) was heparinized and dealt with the ultraviolet irradiation (wave length 240-300 nm) and oxygenation. And then it was infused for the first antegrade coronary perfusion when the ascending aorta was cross-clamped, when the UBIO blood was produced, the equivalent quantitative saline was infused from another vein. The 4:1 cold oxygenated blood hyperhalemia cardioplegia was perfused and then maintained for 30 minutes. The control group was the same as the test group except that the cardiac arresting solution presented without the 4:1 cold oxygenated blood.MAIN OUTCOME MEASURES: Blood samples were withdrawn from coronary venous sinus before cross-clamping and at minutes 5 and 10 after aorta declamping, to measure the levels of superoxide dismutase (SOD) and the content of malondialdehyde (MDA). Before the beginning of CPB, and at hours 4, 24, and 48 after the end of CPB, venous blood was drawn to test the serum cardiac troponin I(cTnI) and creatine kinase isozyme (CK-MB).RESULTS: MDA levels of plasma were less in the test group than that of the control group after aorta declamping (P < 0.05),while the SOD activity was obvious greater than the control group (P < 0.05). At hours 4-48 after CPB, CK-MB and cTnl levels were lower in the test group than the control group (P< 0.05).CONCLUSION: Antegrade coronary first perfusion with UBIO during CPB has evident cardiac protective in old patients undergoing valve replacement by elevating SOD activity, decreasing MDA level, relieving myocardial reperfusion injury, as well as decreasing myocardial damage markers levels.

The effects of in vivo local expression of recombined human tissue-type plasminogen activator (t-PA) gene on the thrombosis and neointima formation of vein grafts were explored. Jugular vein-to-artery bypass grafting was performed on 72 New Zealand white rabbits. The rabbits were divided into 3 groups according to the different processing methods: transfected t-PA gene group (n = 24), vector group (n = 24) and blank control group (n = 24). Samples of vein grafts were harvested at different time points after surgery. The expression of t-PA gene in vein graft was detected by RT-PCR and the synthesis of t-PA protein by Western-Blot assay. The t-PA activity was measured by chromogenic substrate assay. The Cr51 labeled platelets accumulation in vein grafts was counted. The histopathological changes were compared in intima hyperplasia index among the three groups after operation. The results showed that at the 2nd, 5th, 14th and 28th day after operation, RT-PCR and Western-blot confirmed the expression of t-PA mRNA and protein at the site of gene transfer. The t-PA activity detected on the 2nd, 5th, 14th and 28th day in experimental group was 370.63 +/- 59.44, 344.13 +/- 48.47, 252.87 +/- 51.80 and 161.75 +/- 68.94 U/g respectively, and disappeared on the 60th day and undetected in the control groups. The number of platelets accumulated in the vein grafts in gene group, vector group and blank control group was (85.04 +/- 21.58) 10(6), (225.87 +/- 85.13) 10(6) and (211.7 +/- 78.02) 10(6) respectively. The number of platelets accumulated in gene group was significantly fewer than that in the control groups. Morphometric analysis revealed that intimal hyperplasia was markedly reduced in the t-PA gene group as compared with that in the control groups. It was suggested that the local expression of t-PA gene in vein graft significantly inhibited the accumulation of platelets, thrombosis and concomitant intimal hyperplasia, by which stenosis of bypass graft could be prevented effectively.

Objective To investigate the association between the apolipoprotein E (apoE) gene polymorphism and the dose for warfarin individual maintenance. Methods The genotypes of 249 patients with warfarin treatment in maintenance doses were determined by PCR/DHPLC assay. The doses for warfarin maintenance were compared among patients with different genotypes. Results In the total of 249 patients, the frequencies of 2/ε2, ε2/ε3, ε2/ε4, ε3/ε3, ε3/ε4, ε4/ε4 genotype were 1.20%, 15.66%, 1.80%, 72.29%, 9.24%, 0.80%, respectively; the allele frequencies of ε2, ε3, ε4 were 9.44%, 84.74%, 5.82%, respectively. The warfarin dose of group ε2 (ε2/ε2, ε2/ε3) was (3.24±1.36) mg/d, slightly higher than that of group ε3 (ε3/ε3, 2.91±1.14 mg/d) or group ε4 [ε4/ε4, ε3/ε4, (2.98±1.05) mg/d], but the difference of the warfarin doses among the 3 groups did not reach statistical significance (F=1.848,P＞0.05). Conclusion ApoE polymorphism may be not a major genetic factor that influences the individual dose for warfarin maintenance.

Tetralogy of Fallot with unilateral absence of pulmonary artery is a rare congenital malformation. There is a lack of unified treatment strategy with controversy exist, and surgeons are confused in the process of clinical decision-making. This review discusses the clinical classification and treatment of Tetralogy of Fallot with unilateral absence of pulmonary artery, with the aim of providing reference for the clinical decision-making for cardiovascular surgeons.

Objective To evaluate the effect of nicorandil on early prognosis in patients undergoing cardiac valve replacement with cardiopulmonary bypass (CPB).Methods Forty American Society of Anesthesiologists physical status Ⅱ or Ⅳ patients,aged 18-64 yr,with New York Heart Association grade Ⅱ or Ⅲ,scheduled for elective cardiac valve replacement with CPB,were divided into 2 groups (n =20 each) using a random number table method:control group and nicorandil group.Nicorandil was intravenously infused at 10-60 μg · kg-1 · h-1 (3-15 ml/h) after anesthesia induction until the end of surgery in nicorandil group.Before anesthesia induction (To) and at 6,12,24,48 and 72 h after surgery (T1-5),and when the patients were discharged from hospital (T6),venous blood samples were obtained for determination of the concentrations of serum cardiac troponin I (cTnI) and brain natriuretic peptide.The events of myocardial ischemia or development of arrhythmia before and after surgery,development of defibrillation during restoration of heart beat,spontaneous heart beat,drug administration during restoration of heart beat,heart rhythm after restoration of heart beat,and the requirement for cardiovascular drugs during and after surgery were recorded.The mechanical ventilation time,duration of intensive care unit stay,and length of postoperative hospital stay were also recorded.Results Compared with control group,the concentrations of serum cTnI at T2,3 and brain natriuretic peptide at T2-6 were significantly decreased,the consumption of intraoperative norepinephrine and postoperative dobutamine was reduced,and the ventilation time and duration of intensive care unit stay were shortened (P＜0.05),and no significant change was found in the rate of defibrillation,restoration of spontaneous heart beat,requirement for drugs during restoration,heart rhythm after restoration or duration of postoperative hospital stay in nicorandil group (P ＞ 0.05).Conclusion Continuously infusing nicorandil during surgery can reduce myocardial injury and improve early prognosis in patients undergoing cardiac valve replacement with CPB.

The effects of L-carnitine, as an ingredient of cardioplegia solution, on cardiac function and cardiomyocyte apoptosis in patients undergoing heart valve replacement operation were investigated. Twenty-three cases undergoing heart valve replacement with cardiopulmonary bypass (CPB)were randomly allocated into two groups: L-carnitine group (n= 12, 12 g/L L-carnitine was put in the ST. Thomas cardioplegia) and control group (n= 11, identical to the L-carnitine group except that normal saline was administered instead of L-carnitine). Serum cardial troponin I (cTnI) levels,the left ventricular ejection fraction (LVEF), and cardiac index (CI) were measured perioperatively. A bit of myocardial tissue obtained from right atria was taken before CPB and by the end of intracardiac procedure to undergo electron microscopy examination and estimate apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). From the end of CPB to 3 days after operation, the serum levels of cTnI in the L-carnitine group was significantly lower than that in the control group (P＜0.05). Heart color ultrasonogram showed that the CI index and LVEF at 7th day postoperatively in the L-carnitine group were significantly higher than in the control group (P＜0.05). Compared to the control group, L-carnitine significantly alleviated the morphologic changes of cardiac muscle cells (electron microscopy examination) and decreased the amounts of apoptotic cardiac muscle cells (TUNEL). Furthermore, the dosage of vasoactive drugs used after operation was significantly less in the L-carnitine group (P＜0.01). It was concluded that L-carnitine cardioplegia solution could improve cardiac function in patients undergoing heart valve replacement operation and alleviate CPB-mediated apoptosis of cardiac muscle cells.

The effects of in vivo local expression of recombined human tissue-type plasminogen activator (t-PA) gene on the thrombosis and neointima formation of vein grafts were explored. Jugular vein-to-artery bypass grafting was performed on 72 New Zealand white rabbits. The rabbits were divided into 3 groups according to the different processing methods: transfected t-PA gene group (n =24), vector group (n=24) and blank control group (n=24). Samples of vein grafts were harvested at different time points after surgery. The expression of t-PA gene in vein graft was detected by RT-PCR and the synthesis of t-PA protein by Western-Blot assay. The t-PA activity was measured by chromogenic substrate assay. The Cr51 labeled platelets accumulation in vein grafts was counted. The histopathological changes were compared in intima hyperplasia index among the three groups after operation. The results showed that at the 2nd , 5th , 14th and 28th day after operation,RT-PCR and Western-blot confirmed the expression of t-PA mRNA and protein at the site of gene transfer. The t-PA activity detected on the 2nd, 5th, 14th and 28th day in experimental group was 370. 63±59.44, 344. 13±48.47, 252. 87±51.80 and 161. 75±68.94 U/g respectively, and disappeared on the 60th day and undetected in the control groups. The number of platelets accumulated in the vein grafts in gene group, vector group and blank control group was (85.04 ± 21.58) 106,(225. 87±85.13) 106 and (211. 57±78.02) 106 respectively. The number of platelets accumulated vealed that intimal hyperplasia was markedly reduced in the t-PA gene group as compared with that in the control groups. It was suggested that the local expression of t-PA gene in vein graft significantly inhibited the accumulation of platelets, thrombosis and concomitant intimal hyperplasia, by which stenosis of bypass graft could be prevented effectively.