ISSN:0889-4655    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

While cardiac pacemakers are frequently used for the treatment of bradydysrhythmias (from diseases of the cardiac conduction system), their use is still limited by complications that can be life-threatening and expensive. Genetic engineering approaches offer an opportunity to modulate cellular automaticity in a manner that could have significant therapeutic potential. It is well known that ventricular myocytes exhibit a more negative diastolic potential than do pacemaker cells, in large part because of the inward rectifying potassium currentIK1(which pacemaker cells lack). Taking advantage of these intrinsic electrophysiological differences, a biological pacemaker has recently been developed by Miake et al (Nature 2002; 419:132–133) using adenoviral gene transfer approaches. By isolating the gene responsible forIK1(theKir2.1gene), mutating it to make it a dysfunctional channel (a dominant-negative), inserting the mutated gene into an adenoviral vector, and delivering the virus to the hearts of guinea pigs, the investigators were able to successfully convert some ventricular myocytes to pacemaker cells. While issues of safety and long-term efficacy need to be further established, the results of these experiments provide proof of principle that gene transfer offers great promise for treatment of electrophysiological disorders including conduction system disease.

ISSN:0889-4655    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Although major advances have been made in the prevention, diagnosis, and treatment of cardiovascular diseases, the prevalence of these diseases in the US population is almost 62 million, with almost 8 million having had a myocardial infarction and nearly 5 million with a diagnosis of heart failure. Increasingly implantable devices have been used to decrease mortality and morbidity in patients with coronary heart disease. The dramatic reduction in mortality reported in the recent clinical trial of implantable cardioverter defibrillators in MADIT II (Multicenter Automatic Defibrillator Trial II) and decrease in hospitalizations, improved exercise tolerance, and better quality of life with cardiovascular resynchronization therapy reported in MIRACLE (Multicenter InSync Randomized Clinical Evaluation) led the American Heart Association to name treatment with implantable devices as one of the top 10 research advances for 2002. This article reviews the pathophysiology of cardiac dysrhythmia in the context of either heart failure or low ejection fraction, standard medical therapy, results of important clinical trials of implantable cardioverter-defibrillator and offers suggestions for future directions.

ISSN:0889-4655    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Strokes are the third leading cause of death in the United States. Carotid artery occlusive disease accounts for about 20% to 30% of all strokes. Carotid endarterectomy has been the traditional standard treatment for patients with significant carotid artery disease. However, surgical therapy is associated with significant complications. Carotid angioplasty and stenting offers an attractive alternative to surgery. There have been significant advances in this field including the use of embolic protection devices. In this article, we review the current literature addressing the role of endovascular interventions in the management of patients with significant carotid stenosis.

ISSN:0889-4655    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

The surprising results of the Women's Health Initiative (WHI) reported in 2002 had a profound effect on women as well as health care practitioners. The WHI was the largest, randomized clinical trial designed to determine if postmenopausal hormone use prevented cardiovascular disease as well as other age-related disorders in women. While observational studies suggested that postmenopausal use of estrogen could decrease cardiovascular risk by 40% to 50%, the WHI demonstrated that use of continuous-combined estrogen plus progestin was not cardioprotective and was even associated with increased health risks. The estrogen alone trial of the WHI is still in progress, leaving practitioners and some women still in a dilemma. This article addresses the WHI in the context of other studies and discusses possible reasons for the unexpected results.

ISSN:0889-4655    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Within the last decade, health care providers have seen the emergence of numerous patient care guidelines that can be used to prevent or manage specific medical conditions. The American College of Cardiology (ACC) and American Heart Association (AHA) have issued guidelines for the management of patients with acute myocardial infarction (AMI). In November of 2002, at the annual scientific session of the AHA, researchers presented the results of the first study to show a direct relationship between inpatient mortality and the level of a hospital's compliance with these guidelines. It is hoped that this evidence of a reduction in AMI patient mortality will provide an incentive for all hospitals to improve their adherence to the ACC/AHA AMI guidelines.

ISSN:0889-4655    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Current statistics on global obesity are staggering. In 2002, the International Obesity Task Force estimated that worldwide, nearly 1 billion (6%) people were overweight or obese. The American Heart Association's 2002: “Top 10” Research Advances for the Treatment of Heart Disease include obesity as a strong and independent risk factor for developing heart failure. This article outlines national and world statistics, cardiac risk factors, and pathophysiologic theories outlining the cellular mechanisms that associate obesity and heart failure. Access to guidelines for effective screening, evaluation, and treatment of obesity are also provided.

ISSN:0889-4655    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Atrial fibrillation (AF), a rhythm characterized by disorganized depolarization of the atria, is frequently encountered in the clinical setting. This dysrhythmia significantly impacts hemodynamics, exercise tolerance, and quality of life. Many factors contribute to this complex dysrhythmia, ultimately leading to electrical and mechanical remodeling. Rhythm control has been the initial treatment choice for AF. However, until recently, differences in outcomes associated with rhythm control versus rate control for AF were unknown. Data from recent clinical trials suggest that rate control is equivalent to rhythm control in terms of mortality. In the rhythm-control group compared to the rate-control group, there was a tendency for increased hospitalizations and medication reactions (although these differences were not significant). Anticoagulation remains an important component of therapy when treating AF, but continues be to inadequately prescribed. Further, INRs commonly are not maintained in a therapeutic range. Finally, the results of the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM), Pharmacological Intervention in Atrial Fibrillation (PIAF), and the Comparison of Rate Control and Rhythm Control in Patients with Recurrent Persistent Atrial Fibrillation (RACE) trials provide guidance in treatment strategies for AF.

ISSN:0889-4655    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

One of the most promising new therapeutic techniques for the augmentation and regeneration of the myocardium is cellular cardiomyoplasty. Reports from animal and clinical investigations indicate that the transplant of different cell types, such as autologous skeletal myoblasts and adult stem cells, into injured myocardium results in the generation of new cardiac myocytes and improvement in myocardial performance. Although there is no consensus with regard to the best cell type to transplant or the extent of myocardial renewal and regeneration, the technique of cardiac cellular myoplasty may become one of the most important advancements in the treatment of cardiovascular diseases such as myocardial infarction and heart failure.

ISSN:0889-4655    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Over the past decade, advancements in cardiac surgery occurred secondary to improvements in technology and the desire for a less invasive approach to operations in general. Minimally invasive cardiac surgery has progressed from partial sternotomy incisions to totally endoscopic open-heart procedures with robotic-assistance. There are 2 major companies that produce robotic equipment for use in cardiac surgery. These companies must undergo Food and Drug Association (FDA) mandated clinical trials on each cardiac surgical procedure, before it can be approved for public use. The surgeon must demonstrate clinical proficiency to operate the robotic equipment per FDA approved company testing. The use of computer (robotic) enhancement is well documented for coronary artery bypass grafting and selected cardiac valve procedures. Recent advancements are now being directed at congenital heart disease. The use of robotic-assisted totally endoscopic atrial septal defect closure is a tremendous advancement in congenital cardiac surgery. The future of robotic cardiac surgery will hopefully expand to cover more advanced valve procedures, congenital heart defects, and other procedures once robots are further modified for pediatric use.

ISSN:0889-4655    

出版商:OVID    

年代:2003

数据来源: OVID