The effect of myocardial preservation technique on supraventricular tachycardia following aortic valve replacement

We studied 100 patients who underwent an isolated aortic valve replacement (AVR) between 1974 and 1991. The patients were divided into the following two groups and compared: group A, which consisted of 40 patients operated on before 1978 who underwent continuous left coronary perfusion with blood; and group B, which consisted of 60 patients operated on after 1979 in whom St. Thomas solution was used in combination with topical cardiac cooling. Moreover, we divided the group B patients into two subgroups: group Bl, who underwent AVR before 1986 during which we administered St. Thomas solution with ice slush every 30 min; and group B2, who had AVR after 1986 in which we used St. Thomas solution with a cold saline (4°C) solution and treated with a small amount of slushed ice every 15 min. The incidence of supraventricular tachycardias was 15% in group A, 50% in group BI, and 15% in group B2. The severity of preoperative New York Heart Association (NYHA) functional class, the type of valve lesions, cardiothoracic ratio, left ventricular function, aortic clamp time, bypass time, and use of drugs did not correlate with the incidence of supraventricular tachycardias in either group A or B. In group B2 patients, we paid a lot of attention to cooling the right atrium as well as the left ventricle by immersing the whole heart using a 4°C saline solution, which led to a remarkable reduction of the incidence of supraventricular tachycardia. This fact indicates that right atrial preservation is one of the most important factors for reducing the incidence of supraventricular tachycardia.     

Myocardial cooling and right ventricular function in patients with right coronary artery disease: antegrade vs. retrograde cardioplegia

Background: Protection of the right ventricular (RV) myocardium during ischaemia in cardiac surgery is difficult, especially in patients with severe right coronary artery (RCA) disease. Retrograde coronary sinus cardioplegia is thought to distribute uniformly, but doubts still remain as to its adequacy in RV preservation. This study evaluated distribution of antegrade vs. exclusively retrograde coronary sinus cold blood cardioplegia by assessing myocardial cooling and compared the effects on RV function. Methods: Fifty-eight patients scheduled for elective coronary artery surgery - 29 patients with significant RCA disease and another 29 with no significant RCA stenosis (controls) - were randomised to receive either antegrade or retrograde cold blood cardioplegia through either aortic root or conventional self-inflating coronary sinus catheter (RCA-ante, RCA-retro, C-ante and C-retro groups). RV function was assessed by fast-response thermodilution. Myocardial temperatures were measured in the anterior and posterior wall of the right and left ventricle. Results: Cooling of the posterior wall of the RV was effective only in the control patients given antegrade cardioplegia (14.7°C), whereas in the other groups the lowest myocardial temperatures there remained above 20°C (RO.001). In patients with obstructed RCA both antegrade and retrograde cold cardioplegia led to uneven cooling of the myocardium. After cardiopulmonary bypass the RV ejection fraction (RVEF), RV stroke work index (RVSWI) and cardiac index (CI) were significantly reduced in the RCA-retro group, and RVSWI and CI in the C-retro group, too. Regression analysis showed an inverse relationship between the temperatures of the posterior walls of the ventricles and changes in the RVEF and CI. Conclusions: Retrograde and antegrade cardioplegia alone were not effective in reducing the temperature of the posterior wall of the RV in the patients with obstructed RCA, in whom with retrograde cardioplegia RV haemodynamics were impaired for 1 hour following bypass. Neither retrograde nor antegrade cardioplegia alone can be relied on to protect the posterior wall of the RV in the patients with obstructed RCA.     

槲皮素磷酸酯钾对实验性心肌梗塞的影响

iv10～20mg/kg(木解)皮素磷酸酯钾使兔急性心肌梗塞范围明显缩小,ST段明显降低,并能对抗冠脉结扎后引起的血清CPK含量增加及心律失常,这些作用与普萘洛尔相似。但iv40mg/kg后作用不明显。     

PET in cardiology: current status and clinical expectations

Summary. The development of positron emission tomography (PET) in the clinical environment along with the synthesis of biologically active molecules and tracer kinetic principles has provided a diagnostic tool for in vivo tissue characterization in humans. Moreover, based on the growing knowledge of cellular function on the molecular level of diseases PET biological imaging has stimulated the synthesis of numerous metabolic compounds labelled with the four primary positron-emitting radioisotopes C-ll, F-18, N-13 and 0–15. While the concept of biological imaging has gained attraction for probing both the central nervous system and neoplastic tissues, current diagnostic benefit from PET is probably best defined in cardiovascular medicine.     

逆行灌注心脏不停跳心肌保护的实验研究

目的：探讨逆行灌注心脏不停跳心肌保护的效果。方法：中国大白兔32只随机分为4组，每组8只，A组（对照组），B组（心脏不停跳组，血温34℃），C组（温血心脏麻痹液组，血温34℃），D组（冷血心脏麻痹液组，血温4℃）。采用离体兔心左室做功模型，经冠状静脉窦逆行灌注稀释血液或血停搏液60min。比较观察心功能、冠脉排出液心肌酶谱、心肌组织乳酸、心肌细胞内游离钙浓度、心肌细胞膜ATP酶活性、心肌细胞膜脂质过氧化产物丙二醛含量的变化。结果：B组心功能恢复、心肌细胞膜ATP酶活性显著优于C组和D组，C组优于D组；B组心肌酶漏出、乳酸生成量、心肌细胞内游离钙浓度、心肌细胞膜丙二醛（MDA）含量低于C组和D组，C组低于D组。结论：常温氧合血逆灌心脏不停跳良好的心肌保护效果与其减轻自由基损伤，较好地保持细胞内外Ca^2 平衡，减轻细胞内钙超载，保护细胞膜酶功能有关。     

Post-ischemic release of nucleosides and oxypurines in isolated rat hearts. Possible involvement of ventricular fibrillation

Summary In isolated perfused rat hearts global ischemia for 2, 5, and 15 min was produced. Depending on the duration of the ischemia, postischemic reperfusion led to the release of adenosine and its catabolites, and to more or less severe ventricular tachyarrhythmias. When ventricular fibrillation occurred, a highly significant increase in the purine release was observed compared with non-fibrillating hearts. Prevention of fibrillation by antiarrhythmic drugs decreased the purine release in a highly significant way. After only 2 min of ischemia, reperfusion did not lead to ventricular fibrillation. Electrical induction of fibrillation during the reperfusion in these hearts provoked the release of very high amounts of the purine compounds. A similar effect of electrically-induced fibrillation was also obtained in hearts without a previous ischemic period. The findings suggest that ventricular fibrillation is able to induce the release of purine derivatives from the heart.     

变异型心绞痛的发作诱因和合并症

本文报告3例饮酒诱发变异型心绞痛者,2例发展为急性心肌梗塞,1例合并Ⅲ度房室传导阻滞.另3例无诱因的典型变异型心绞痛发作皆无合并症.上述结果提示:饮酒是变异型心绞痛发作的最常见诱因,与无诱因者相比,予后更为严重.因此,有冠状动脉痉挛倾向者如变异型心绞痛,不稳定型心绞痛,卧位或夜间发作的心绞痛等,应避免饮酒.     

经尿道电气化切除术治疗良性前列腺增生症(附1532例报告)

目的 :总结和评价经尿道前列腺电气化切除术 (TUVP)治疗良性前列腺增生症 (BPH)的疗效。方法 :采用铲式气化切割环 ,经尿道气化切除前列腺 1 5 32例。结果 :最大尿流率 (Qmax)由手术前 (7.7± 3.8)ml/s到术后 (1 7.9± 3.2 )ml/s;国际前列腺症状评分由术前 (2 9.5± 3.6 )分到术后 (9.1± 2 .9)分 ;生活质量评分由术前 (5 .5± 0 .3)分到术后 (1 .9± 0 .3)分 ;术中前列腺包膜穿孔 2例 ;术后尿失禁 2例 ,前尿道狭窄 1 7例 ,后尿道狭窄 7例 ;无电切综合征及死亡病例。结论 :TUVP治疗BPH创伤小、出血少、疗效好、术后康复快