Limitation of infarct size by fixed coronary arterial stenosis maintained during reperfusion

BACKGROUND: The effect on infarct size of a pre-infarction high-grade, fixed coronary arterial stenosis maintained during reperfusion, was evaluated. METHODS: This experimental study was carried out in the research laboratory of a University Hospital. A canine occlusion-reperfusion model was used. Twenty-eight dogs underwent proximal left anterior descending (LAD) coronary artery occlusion (O). In Group 1 (n=6) the O lasted for 6 hours. In Group 2 (n=6) the O lasted for 2 hours followed by 4 hours of reperfusion (R). In Group 3 (n=3), LAD was stenosed for 30 minutes followed by O for 6 hours. In Group 4 (n=7) LAD was stenosed for 30 minutes followed by O for 2 hours and then 4 hours of R during which the artery was kept stenosed at the same degree (fixed) as the initial one. In Group 5 (n=6) the protocol was identical to Group 4 with the additional use of the intra-aortic balloon pump during R. RESULTS: The infarcted myocardium was almost the same in Groups 1 and 3 (80.0+/-10.6% vs 77.3+/-3.8%, respectively, p=NS), but less in Group 2 (59.0+/-19.9%, p=0.046 vs Group 1). There were no hemodynamic differences between Groups 4 and 5 and the infarcted myocardium was almost identical in both groups (37.7+/-18.8% and 38.7+/-19.1%, respectively, p=NS). The combined results of Groups 4 and 5, regarding the infarcted myocardium, was 38.1+/-18% (p=0.037 vs Group 2). CONCLUSIONS: In this acute coronary occlusion model, a pre-existing high-grade stenosis that maintained during reperfusion increased the amount of salvaged ischemic myocardium.     

Superior Performance of a Paraaortic Counterpulsation Device Compared to the Intraaortic Balloon Pump

The purpose of this study was to compare the hemodynamic effectiveness of a 30-ml stroke volume paraaortic counterpulsation device (PACD), presenting the advantages of ease of implantation and driving by a standard intraaortic balloon pump (IABP) console (Datascope 96, Datascope Corp., Montvale, NJ, USA) to that of a 40-ml IABP, in the setting of experimental heart failure. In an acute heart failure model, the IABP was placed in the descending aorta and the PACD in the ascending aorta of eight pigs. Both devices were driven by the same system, and hemodynamic measurements were obtained with and without mechanical assistance. The two pumps significantly reduced the systolic and end-diastolic aortic pressures, but the PACD reduced the latter more effectively (42.6 ± 18.1% vs 11.0 ± 9.9%, p = 0.0001). Both pumps provided significant aortic diastolic augmentation, but the counterpulsation wave of the PACD was significantly greater (augmentation of 44.8 ± 22.2% vs 37.6 ± 15.6%, p = 0.031). Both lowered the end-diastolic left ventricular pressure with a trend toward PACD superiority (24.2 ± 13.7% vs 19.7 ± 13.5%, p = 0.064). It is concluded that the PACD, even with smaller stroke volume, is more effective than the IABP. The simplicity of its implantation, together with the ability of the standard IABP consoles to control its function, make it a promising device for mechanical assistance of the failing heart.     

长春瑞滨联合顺铂治疗32例多柔比星耐药的晚期乳腺癌

目的：观察长春瑞滨(诺维本，NVB)联合顺铂(DDP)治疗多柔比星(ADM)耐药的晚期复发、转移乳腺癌的近期疗效和毒副反应。方法：用NP方案对曾用含多柔比星联合方案治疗大于2周期后进展或复发、转移的晚期乳腺癌32例，21～28天为1周期，完成2～4周期后评价疗效。结果：总有效率62．5％，主要限量毒性为消化道反应和骨髓抑制，其次为周围神经炎。结论：NVB加DDP治疗多柔比星耐药的晚期乳腺癌仍是可供选择的有效方案，毒副反应可耐受。     

内源性逆病毒癌基因V-erbB突变与白血病发生

目的：证明鸡原始红细胞增多症逆病毒癌基因V—erbB在人类白血病和骨髓增生异常综合征(MDS)急者基因组内的存在。方法：应用V—erbB PCR，V—erbB寡核苷酸(Oligo)原位杂交技术和PCR产物DNA测序，对84例MDS、可疑MDS和49例其他相关血液病进行检到。结果：2例患者骨殖细胞基因组内均存在V—erbB亚基因片段，同源性占99．5％，它们具有相同的限制性酶勿位点，因此可以在Southern印迹杂交条件下发生骨髓细胞C—erbB重排和重排／扩增。白前P1P2PCR产物有420bp，P1P3产物有650bp，而白血病(AL—M4)P1P2PCR产物仅390bp，P1P3PCR因P3无模板序列而无结果。提示从白前发展为白血病，可能发生V—erbB亚基因序列的缺失，即缺失突变。结论：大鼠和人白血病和食管癌等可能均起源于其基因组内存在V—erbB亚基因及其缺失突变。白血病发病中除了上述病因以外，骨髓细胞染色体不稳定性可能起协同作用。     

Real-time pelvic ultrasonography as an adjunct to digital examination

The authors suggest that diagnostic accuracy could be improved in 1% of cases by combining real-time ultrasound with digital examination of the pelvis or rectum. Differences of opinion between clinician and ultrasonologist regarding a possible pelvic mass can easily be settled. This technique can also be used to displace loops of bowel, help characterize congenital anomalies, and aid in the training of medical students and residents in obstetrics and gynecology.     

Usefulness of a Collateral Channel Dilator for Antegrade Treatment of Chronic Total Occlusion of a Coronary Artery

Objectives: The aim of this study was to clarify the effectiveness of a collateral channel dilator microcatheter in antegrade percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) of a coronary artery. Background: The Corsair microcatheter, which was originally developed as a collateral channel dilator, has been reported to be useful for retrograde CTO‐PCI. Methods: We compared the success rate of the Corsair microcatheter collateral channel dilator for antegrade CTO‐PCI with a previously available microcatheter. We analyzed the data from 27 patients (32 CTOs) using the FinecrossMG (Finecross group) and the data from 31 patients (34 CTOs) using the Corsair (Corsair group). Results: There were no significant differences in the clinical or lesion characteristics between the 2 groups. The success rate for crossing the CTO by the microcatheter was 62.5% in the Finecross group and 85.3% in the Corsair group (P < 0.05). After the Corsair crossed the CTO, a 2‐mm diameter balloon catheter crossed the lesion in all the cases, but it crossed the lesion in only 17 of 20 cases in the Finecross group (85.0%, P < 0.05). The number of balloon catheters used for predilation was significantly less in the Corsair group compared with the Finecross group (P < 0.05). Conclusions: The success rate for crossing of the microcatheters and the balloon catheters through the occlusion in antegrade CTO‐PCI was better with the Corsair than with the FinecrossMG. In addition, the use of the Corsair reduced the number of balloon catheters used for predilation in antegrade CTO‐PCI. (J Interven Cardiol 2012;25:533–539)     

Ventricular assist devices: pharmacological aspects of a mechanical therapy

Heart failure (HF) is a global epidemic that continues to cause significant morbidity and mortality despite advances in medical therapy. Ventricular assist device technology has emerged as a therapeutic option to bridge patients with end-stage HF to heart transplantation or as an alternative to transplantation in selected patients. In some patients, mechanical unloading induced by ventricular assist devices leads to improvement of myocardial function and a possibility of device removal. The implementation of this advanced technology requires multiple pharmacological interventions, both in the perioperative and long-term periods, in order to minimize potential complications and improve patient outcomes. We herein review the latest available evidence supporting the use of specific pharmacological interventions and current practices in the care of these patients: anticoagulation, bleeding management, pump thrombosis, infections, arrhythmias, right ventricular failure, hypertension, desensitization protocols, among others. Areas of uncertainty and ground for future research are also highlighted.     

Mechanical assistance by intra-aortic balloon pump counterpulsation during reperfusion increases coronary blood flow and mitigates the no-reflow phenomenon: an experimental study

The effects of the intra-aortic balloon pump (IABP) counterpulsation on the extent of myocardial infarction (MI), the no-reflow phenomenon (NRP), and coronary blood flow (CBF) during reperfusion in an ischemia-reperfusion experimental model have not been clarified. Eleven pigs underwent occlusion of the mid left anterior descending coronary artery for 1 h, followed by reperfusion for 2 h. CBF, distal to the occlusion site, was measured. In six experiments, IABP support began 10 min before, and continued throughout reperfusion (IABP Group). Five pigs without IABP support served as controls. At the end of each experiment, the myocardial area at risk (MAR) of infarction and the extent of MI and NRP were measured. Hemodynamic measurements at baseline and during coronary occlusion were similar in both groups. During reperfusion, systolic aortic blood pressure was significantly lower in the IABP Group than in controls. In the IABP Group, CBF reached a peak at 5 min of reperfusion, gradually decreased, but remained higher than at baseline, and significantly higher than in controls throughout the 2 h of reperfusion. In controls, CBF increased significantly above baseline immediately after the onset of reperfusion, then returned to baseline within 90 min. The extent of NRP (37 ± 25% vs. 68 ± 17%, P = 0.047) and MI (39 ± 23% vs. 67 ± 13%, P = 0.036), both expressed as percentage of MAR, was significantly less in the IABP group than in controls. After prolonged myocardial ischemia, IABP assistance started just 10 min before and throughout reperfusion increased CBF and limited infarct size and extent of NRP.