ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Impairment of coronary flow, or low coronary reflow, is an important feature of ischemia-reperfusion injury. It is known to be associated with a significant diminution of basal and stimulated release of nitric oxide. The degree of recovery of low coronary reflow and of basal and stimulated release of nitric oxide diminishes with age and is influenced by the type of cardioplegic solution used. Underlying mechanisms include L-arginine (the physiologic substrate of nitric oxide) deficiency, G protein alteration, and nitric oxide inhibition by free radicals. Under normal conditions, basal release of nitric oxide is known to play a crucial role in the maintenance of basal coronary flow and appears to be essential for sustaining mechanical activity. Methods of preservation targeting reperfusion, ischemia, and preischemia have been evaluated. Pharmacologic modulation, crystalloid solution at 4°C, and induction of heat-shock proteins (an intrinsic protective mechanism) reverse the postischemic dysfunction of nitric oxide release.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Transmyocardial laser revascularization is currently being tested in randomized clinical trials as an alternative technique for relieving angina in patients with ischemic myocardium. In this technique, an 800-W carbon dioxide laser is used to create channels in the myocardium that open directly into the left ventricular cavity. Although the exact mechanism by which tissue revascularization occurs is not yet known, initial results from an earlier clinical trial were promising: a significant number of patients were relieved of angina symptoms, exercise tolerance was improved, complications were minimal, and the safety of the technique seems established. A controlled, randomized trial is now underway, and initial results appear promising.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

The treatment of ischemic heart disease by coronary artery bypass grafting remains under intense scrutiny. A better understanding of the long-term outcome for particular patient subgroups will allow a more appropriate choice to be made among the options of coronary artery bypass grafting, angioplasty, or continued medical management. Such information would also permit patients to make informed choices when their preferences influence the decision. A clearer understanding of the importance of risk-factor management (in particular lipid reduction by drug treatment) will improve the long-term results for patients undergoing surgical treatment (probably in both late mortality and late clinical events). Such an understanding can also clarify the need for further intervention.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Smooth muscle cells migrate into the vascular intima, proliferate, and lay down extracellular matrix, thereby forming an important component of the occlusive mass of atherosclerotic plaques in native arteries and in saphenous vein grafts. The viability of smooth muscle cells and the integrity of their surrounding extracellular matrix also determine the liability of plaques to rupture and hence precipitate myocardial infarction and vein graft occlusion. This update reviews recent developments in the molecular understanding of relevant aspects of smooth muscle cell biology. It highlights the increasing importance attached to interactions between growth factors and components of the extracellular matrix in regulating migration and proliferation and the new roles assigned to apoptosis in these cells. It illustrates, furthermore, how the application of the techniques of molecular biology is identifying new targets for conventional and gene therapy.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Angioplasty and bypass surgery have become standard methods of treating patients with symptomatic coronary atherosclerosis. Although both procedures have been applied to a wide spectrum of patients with acceptable morbidity and mortality, only recently have randomized trials been performed to directly compare their efficacies. In patients with multivessel disease, overall mortality and freedom from myocardial infarction appear to be similar between the two treatment strategies. Primarily due to restenosis, the need for repeat revascularization procedures is significantly greater in patients who initially undergo angioplasty. Accordingly, this difference is most striking in the 1st year of follow-up and diminishes over time. The costs of the two treatment strategies reflect the restenosis problem as well. Although angioplasty initially costs less than bypass surgery, the cost savings largely abate after repeat interventions are performed.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

The radial artery is being reintroduced into clinical practice to increase the number of arterial grafts for patients undergoing coronary artery bypass surgery. The radial artery is readily available from one or both forearms and removal is safe in patients who have a normal collateral circulation to the hand. Harvesting the radial artery with the adjacent veins using a minimal touch technique and vasodilators will prevent vasospasm and possibly early occlusion. A concern is that subclinical atheroma is present in many patients. The radial artery can be used as a single graft, anastomosed in a “Y” fashion with the internal mammary artery, or used as a sequential graft. The early mortality and complications are low. There are potential cost savings because the need for an incision in the leg is avoided, so that patients may be discharged early. The early results of radial artery grafting are encouraging. Further follow-up is required to determine the late patency and effects on survival of using the radial artery graft.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Early release following cardiac surgery can be facilitated by the implementation of a standard protocol for pre- and postoperative care. This protocol involves aggressive pharmacologic therapy together with education and support. Accelerated recovery and release is inherently attractive because the duration of intensive care unit stay and hospital stay are the most important determinants of costs. However, in the desire for reduced costs, patients must clearly benefit from earlier rehabilitation and release. Retrospective studies have shown no significant differences in mortality or morbidity in patients who have undergone conventional versus “fast-tracked” care following cardiac surgery, and follow-up surveys have shown a high level of patient satisfaction with the care. Some centers report that, without exception, all cardiac surgery patients are now fast-tracked.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Cardiopulmonary bypass has been demonstrated to produce a state of functional hypothyroidism characterized by low levels of circulating tri-iodothyronine and elevated levels of reverse Tri-iodothyronine. This low tri-iodothyronine state may have significant hemodynamic consequences similar to that seen with chronic hypothyroidism. In a number of experimental models, evidence has accumulated suggesting that tri-iodothyronine supplementation to the ischemically injured heart enhances ventricular contractile performance. Clinically, tri-iodothyronine supplementation after cardiac surgery improves hemodynamics, although the population of patients who might benefit from this unconventional therapy remains unclear. In this article, the rationale and experimental evidence for the use of tri-iodothyronine during cardiac surgery are reviewed.

ISSN:0268-4705    

出版商:OVID    

年代:1996

数据来源: OVID