Ischemic postconditioning: brief ischemia during reperfusion converts persistent ventricular fibrillation into regular rhythm

Objectives: Brief episodes of myocardial ischemia-reperfusion employed during reperfusion after a prolonged ischemic insult may attenuate the total ischemia-reperfusion injury. This phenomenon has been termed ischemic postconditioning. In the present study, we studied the possible effect of postconditioning on persistent reperfusion-induced ventricular fibrillation (VF) in the isolated rat heart model. Methods: Isolated Langendorff-perfused rat hearts (n=46) were subjected to 30 min of regional ischemia and reperfusion. The hearts with persistent VF (n=11) present after 15 min of reperfusion were then randomly assigned into one of the two groups: (1) control hearts (n=6), in which perfusion was continued without intervention; (2) postconditioned hearts (n=5) subjected to 2 min of global ischemia followed by reperfusion. Left ventricular pressures, heart rate, coronary flow, and electrogram were monitored throughout the experiment. Results: Conversion of VF into regular rhythm was observed in all hearts subjected to postconditioning. Regular beating was maintained by all postconditioned hearts during the subsequent reperfusion. None of the hearts in the control group had normal rhythm at the end of the experiment. At the end of reperfusion, the left ventricular developed pressure was lower in beating postconditioned hearts compared to the hearts that did not develop persistent VF. Conclusions: Ischemic postconditioning possesses strong antiarrhythmic effect against persistent reperfusion-induced tachyarrhythmias. Postconditioning may be an interesting, novel adjunct strategy to protect the heart.     

重度充血性心力衰竭患者心率和每搏输出量的凌晨分离现象研究

目的 研究重度充血性心力衰竭患者血流动力学的昼夜节律改变.方法 选择2005年12月至2006年6月在南京中医药大学无锡附属医院心内科住院的重度充血性心力衰竭患者120例为心衰组,同期门诊体检的无心血管疾病者20名为对照组,采用生物阻抗法每小时1次动态监测心率(HR)和每搏输出量(SV).结果 心衰组与对照组HR、SV均存在昼夜节律,但分布规律存在差异,心衰组HR明显快于对照组(P＜0.5),而SV明显低于对照组(P＜0.05);对照组HR与SV呈正相关(P＜0.01),而心衰组HR与SV总体上也呈正相关(P＜0.01),但在凌晨100～400之间,两组HR与SV分布曲线明显不同,心衰组HR与SV分布曲线出现分离现象,HR下降而SV上升,呈负相关(P＜0.01),而同时段的对照组HR与SV则仍呈正相关(P＜0.01).结论 重度充血性心力衰竭患者HR和SV分布的昼夜节律受损,在凌晨100～400之间,HR与SV分布趋势存在分离现象.     

The use of telescoping guide catheters for coronary sinus cannulation and sub-selecting tributaries in left ventricular lead placement

Introduction Failure to enter the coronary sinus (CS) with a guiding catheter and entering its tributaries remains challenging in left ventricle (LV) pacing lead implants for cardiac resynchronization therapy (CRT). A dual telescoping catheter system (8F outer/6F inner) is designed to provide the ability to adjust the catheter curve size, shape and/or reach to the patients’ anatomy avoiding the need for catheter change. Methods Five different designs for CS cannulation were randomly tested in 64 patients scheduled for CRT device implant. Results In 33 consecutive patients three adaptable telescoping guiding catheter systems were tested per patient, the adaptable catheters had higher overall cannulation success rates (68, 63 and 62%) compared to the fixed shape catheter (46%) and an greater cannulation success rate when the CS location was not known (70, 53 and 72% vs 33% for the fixed shape). In a second group of 31 CRT patients the two telescoping catheters had similar high levels of success (71–80%), with or without using the inner catheter. Conclusions The telescopic system is adaptable to a wide range of anatomical variations in patients and can result in a higher CS cannulation success rate due to its adjustability in the RA in search for the CS ostium. On top of this the inner catheter allows for sub-selecting the CS tributaries.     

Integrated home monitoring predicts lead failure in a pacemaker dependent 4-year-old girl.

A 4-year-old girl with post-surgical complete atrioventricular block received an epicardial dual chamber pacemaker system. During further growth intermittent exit block occurred, first misinterpreted as neurological seizures. The epicardial lead was replaced using a transvenous approach, and a pacemaker with an integrated home monitoring facility was implanted. After her discharge, a rise in the pacing threshold automatically initiated an event message. On the basis of this information, the patient was called in and imminent dislodgement of the ventricular lead was diagnosed by x-ray. The lead was repositioned and was found stable over 1-year follow-up.     

小儿先天性心脏病数据库系统的建立及应用

目的为初步建立国内小儿先天性心脏病(先心病)的诊断及治疗标准,提高数据统计效率,探索构建先天性心脏病数据库系统(congenital heart disease database project,CHDDP)。方法采用Egrid.NeT建立CHDDP,将2006年度2051例次先心病手术(含188例普胸手术)进行统计分析,对比国际知名先天性心脏病数据库系统,结合我国实际情况,对小儿先天性心脏病及常见胸部疾病进行归纳整理。结果CHDDP大大提高了小儿先天性心脏病临床工作效率,同时也可高效地对数据进行统计分析。目前CHDDP已在国内数家先心病治疗单位开始推广,获得一定好评。结论建立CHDDP有助于对国内小儿先心病诊断治疗标准进行统一,加强多中心协作,对于推动我国小儿先心病治疗水平的提高具有重要意义。     

改良Norwood手术临床应用

目的总结改良Norwood手术的临床应用经验。方法2004年7月和2005年3月分别为1例7月龄单心室伴左心室流出道梗阻女婴,采用主肺动脉和主动脉弓下缘直接吻合、主动脉肺动脉人工血管分流完成改良Norwood手术;1例出生13 d左心发育不良综合征新生儿,采用主肺动脉和主动脉弓下缘直接吻合、右心室肺动脉人工血管分流完成改良Norwood手术。结果例1术后平稳,动脉压为85～100/25～40mmHg（1 mm Hg=0．133kPa）,动脉血氧饱和度为0．75～0．85,术后第3d撤离辅助呼吸,第11 d出院。例2术后平稳,动脉压为65～80／40～60mmHg,动脉血氧饱和度为0．67～0．89,术后第12 d撤离辅助呼吸,第28 d出院。结论改良Norwood手术的先进方法和技术,值得在我国推广应用。     

卵圆孔未闭动物模型的建立

目的 探讨采用正常中华小型猪制作卵圆孔未闭动物模型的可行性。方法 中华小型猪11只，选取1只行预实验，10只用于正式实验。全身麻醉下，经股静脉送入Rups-100穿刺针系统，在透视引导下穿刺房间隔卵圆窝，然后对穿刺点行球囊扩张术。预实验动物术后1d处死，正式实验组动物术后21d处死。心脏取材，行病理检查。结果 11只猪均成功行房间隔穿刺和球囊扩张术，并经心房造影证实建立卵圆孔未闭模型。正式实验组动物除1只术中出现心包积液外，其余术中及术后均无并发症。预实验动物于处死后肉眼观房间隔卵圆窝有-0．7cm×0．8cm缺损，光学显微镜下见红细胞聚集。正式实验组动物于处死后观察，7只可见房间隔卵圆窝愈合，3只分别残留0．1cm×0．2cm、0．2cm×0．2cm、0．1cm×0．3cm缺损。正式实验组动物无论卵圆窝是否愈合，光学显微镜下在穿刺点周围均可见不同程度的局灶性心内膜增生和缺失、淋巴细胞聚集、心肌细胞肿胀、坏死和间质纤维化。结论 采用房间隔穿刺和球囊扩张的方法，用中华小型猪建立卵圆孔未闭模型是可行的。     

Complications Related to Dapsone Use for Pneumocystis Jirovecii Pneumonia Prophylaxis in Solid Organ Transplant Recipients

Dapsone, used for prevention of Pneumocystis jirovecii infections, has been reported to cause hemolytic anemia and methemoglobinemia; its tolerability in solid organ transplant recipients is not well described. We investigated dapsone-related adverse events in patients undergoing solid organ transplantation from 1999 to 2004. Transplant providers identified patients for the investigators who then reviewed the patients' hospital and outpatient records. Sixteen solid organ transplant recipients fit case definitions for dapsone-related hemolytic anemia (n = 11) or methemoglobinemia (n = 5). Median time from event to dapsone discontinuation was 15 days; all patients improved after drug discontinuation. G6PD enzyme activity was normal in all patients whose test results were available. Dapsone may be associated with hemolytic anemia or methemoglobinemia, even with normal G6PD levels. These events are often not promptly recognized, and drug discontinuation is delayed. Dapsone-related hemolytic anemia or methemoglobinemia should be considered in solid organ transplant recipients with unexplained anemia or hypoxia.     

Effects of Hostility on Alcohol Stress-Response-Dampening

The purpose of this study was to compare the stress-response-dampening (SRD) effect of alcohol in hostile and nonhostile men based on a combined score of four subscales of the Cook-Medley Hostility Scale . Subjects were 72 male social drinkers. Subjects' cardiac interbeat-interval, and systolic and diastolic blood pressure reactivity to a situational stressor were measured following the consumption of either alcohol, no alcohol, or an active placebo beverage. Results demonstrated that hostile men evinced lower heart rate and systolic blood pressure (SBP) reactivity to the stressor when given alcohol, compared with intoxicated nonhostile subjects, and lower reactivity relative to all other groups, with the exception of SBP in the nonhostile controls. These results allow for speculation that hostile men may be more likely than controls to experience possible SRD effects of alcohol and thus, perhaps, be predisposed to increased alcohol consumption when under stress.     

Cardiovascular malformations and organic solvent exposure during pregnancy in Finland

In order to investigate the possible association between cardiovascular malformations and maternal exposure to organic solvents during the first trimester of pregnancy, 569 cases and 1,052 controls were retrospectively studied. The cases represented all infants with diagnosed cardiovascular malformations born in Finland in 1982-1984, and the controls were randomly selected from all normal births in the country during the same period. All mothers were interviewed approximately 3 months after delivery by a midwife using a structured questionnaire. Exposures to organic solvents at work during the first trimester of pregnancy were slightly more prevalent among the mothers of affected infants (10.4%) than among those of controls (7.8%). Logistic regression analysis of exposure to organic solvents showed an adjusted relative odds ratio of 1.3 (95% confidence interval, 0.8-2.2). In the analysis of ventricular septal defect, exposure to organic solvents showed an adjusted relative odds ratio of 1.5 (95% confidence interval, 1.0-3.7).