Changes in nitric oxide level and guanosine monophosphate activity after ischemic preconditioning in diabetes myocardium: in vivo rat hearts / 中华胸心血管外科杂志

Objective To study the changes of nitric oxide (NO),guanosine monophosphate(cGMP) and nitric oxide synthase (NOS) expression of diabetic rat heart after ischemic preconditioning (IPC),and to explore the possible mechanism of diabetes mellitus inhibiting myocardial protection of IPC.Methods Thirty diabetic SD rats and thirty non-diabetic SD rats were divided into 3 groups (n =10) randomly.Control group (Sham group,n =10),After surgery,no procedures were made; After 155 min,the experiment was ended.Ischemic preconditioning group ( IPC group,n =10),the rats were subjected three cycles of five minutes of ischemia followed by five minutes of reperfusion and then subjected to 30 minutes of ischemia followed by 90 minutes of reperfusion.Ischemia/reperfusion group( I/R group,n =10),after surgery,the rats were balanced for 35 minutes and then subjected to 30 minutes of ischemia followed by 90 minutes of reperfusion.At the end of the experiment,the hearts of each group were excided quickly,frozen in liquid nitrogen and stored at 80 ℃ until membrane and cytoplasm preparation.The changes of activities of the serum creatine kinase (CK),creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH) were detected.The activity of malonyldialdehyde (MDA),superoxide dismutase (SOD) in myocardium were dectected were assessed.In addition,the changes of content of myocardial cGMP and NO were assessed.Ultrathin sections 70 nm thick was made and transmission electron microscopy was used to detect the structure of the mitochondria with the Flameng scoring system.Results Myocardial enzyme leakage and mitochondria injury were significantly reduced compared IPC group and I/R group in non-diabetic rats,and cGMP,NO and NOS were also significantly increased (P ＜0.05 ).There did not show significant myocardial protective effect in diabetic rats,cGMP.NO and NOS showed also no significant increase in diabetic rats ( P ＞ 0.05 ).Conclusion Diabetes inhibited the protective effect of ischemic preconditioning on ischemic reperfused rat heart,which may be related with inhibiting of the expression of the NO-cGMP signaling pathway.

Early hemodynamic evaluation of aortic valve replacement with Hancock Ⅱ Ultra valve / 中华胸心血管外科杂志

Objective To study the aortic valve replacement with Hancock Ⅱ Ultra valve and its early hemodynamic results.Methods The 30 patients who received Hancock Ⅱ Ultra aortic valve replacement at our hospital were matched 1 ∶1 with 30 patients who received Hancock Ⅱ on variables known to affect hemodynamic measurements:size of valve,age,sex,and body surface area.Early postoperative transthoracic echocardiography was performed in all patients.Results 3 months postoperatively,Hancock Ⅱ Ultra valves had significantly lower transvalular gradients,velocity,left ventricle mass index and larger effective orifice area.Compared with Hancock Ⅱ valves,in ≤22 mm group,Hancock Ⅱ Ultra valves had significantly lower transvalular velocity[ (2.26 ± 0.05 ) vs ( 2.57 ± 0.06 ),t =2.07,P ＜ 0.05 ],lower transvalular mean gradients [(11.4 ±1.3) vs (13.1 ±1.5),t =2.09,P＜0.05],higher effective orifice area[ (0.79 ±0.13)vs(0.71 ±0.02),t =2.06,P＜0.05],lower left ventricle mass index[ (119.1 ± 11.1)vs(133.2 ±16.4),t =2.67,P ＜0.05] and bigger left ventricle outflow tract (20.4 ±0.3 vs 18.9 ±0.2,t =2.23,P＜0.05).Conclusion The Hancock Ⅱ Ultra valve has more favorable early postoperative hemodynamics than the Hancock Ⅱ,especially for the small aortic ring patients.

Treatment strategy of supraventricular tachycardia after coronary artery bypass graft / 中国医师进修杂志

Objective To summarize the treatment experience of supraventricular tachycardia (SVT) after coronary artery bypass graft (CABG). Methods The clinical data of 136 patients who had occurred SVT after CABG between January 2008 and December 2009 were analyzed retrospectively. Results Among 136 patients,no perioperative mortality,atrial fibrillation (AF) occurred in 110 cases (80.88%),paroxysmal supraventricular tachycardia (PSVT) occurred in18 cases ( 13.24% ), atrial flutter occurred in 8 cases (5.88%),112 of 136 cases occurred in 1-3 days after surgery,accounting for 82.35% ,24 cases occurred in 4-7 days after surgery,accounting for 17.65%. Given amiodarone in the treatment of 105 cases,100 cases reverted to sinus rhythm (cardioversion rate of 95.24% ),given esmolol in the treatment of 11 cases, 9 cases reverted to sinus rhythm( cardioversion rate of 81.82% ), synchronous direct current cardioversion in 20 cases, all transferred to sinus rhythm, all patients with improved symptoms. The remaining failed to transfer to sinus rhythm, had got normal ventricular rate, and symptoms improved significantly. Conclusions It is necessary to take effective measures to prevent SVT within 3 days after CABG. Amiodarone, esmolol and synchronous direct current cardioversion can be used effectively and safely to control SVT after CABG.

Measures for decreasing the early mortality after atrial septal defect and ventricular septal defect with unsuccessful interventional treatment / 中国医师进修杂志

Objective To probe the effective measures for decreasing the early mortality after unsuccessful interventional treatment for atrial septal defect(ASD)and ventricular septal defect(VSD).Methods A total of 16 patients who underwent surgical treatment of unsuccessful interventional treatment for ASD and VSD from January 2000 to December 2007 were included in this retrospective analysis.Surgical indication was the occluder abscission(7 cases),cardiac perforation(3 eases),the third degree atrioventricular conduction block(3 cases),valvular regurgitation(2 cases,1 case accompanied with the third degreeatrioventricular conduction block),residual shunt(1 case),unsuecesflful interventional treatment(1 case).An of 16 cases underwent surgical treatment including removal of the displaced occluder and/or the congenital heart disease repaired on cardiopulmonary bypass.After surgical treatment.all patients were transferred into ICU for further supervision and treatment.Results There Was no hospital mortality.Twelve ASD cases were performed after the interventional treatment,which included 5 cases with central ASD and 7 CaseS with inferior sinus venous ASD.Coincidental rate between operating exploration and preoperative diagnosis was 41.7%(5/12).Misdiagnostic rate between them was 58.3%(7/12).The diameter of ASD (31.0 ±1.0)mm by operating exploration after interventional therapy of ASD obviously increased compared with that(26.0±2.3)mm before preoperative diagnosis(P<0.05).The diameter of VSD(5.0±0.8)mm by operating exploration after intervenfional therapy of VSD obviously increased compared with that(4.0±0.3)mm before operative diagnosis(P>0.05).,The third degree atrioventricular conduction block(3 cases)restored sinus rhythm after operation.Procedure was successful in all patients.Conclusion It is necessary to monitor severe complications of unsuccessful interventional treatment for ASD and VSD to assure the successes of the operations.