ISSN:0268-4705    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Pulmonary complications are common after coronary artery bypass grafting. Identifying those individuals with increased risk of respiratory complications allows for appropriate preoperative intervention. The most commonly seen pulmonary complications include pleural effusion, hemothorax, atelectasis, pulmonary edema, diaphragmatic dysfunction, and pneumonia. Clinical features and appropriate management of these common problems are discussed.

ISSN:0268-4705    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Spontaneous dissections of the carotid and vertebral arteries in the neck are a common cause of stroke in young and middle-aged people. Moreover, they are increasingly recognized as the cause of a wide variety of other, more subtle, neurologic signs and symptoms. The cause of these arterial dissections largely remains unexplained but probably involves a combination of genetic and environmental factors. Magnetic resonance imaging has largely surpassed angiography as the imaging study of choice. The treatment of carotid and vertebral artery dissections is based on rather incomplete evidence. Anticoagulation with heparin followed by warfarin remains the treatment of choice in most major medical centers and is supported by the demonstration of emboli as the most common cause of stroke in these patients. The burgeoning interest in endovascular techniques has resulted in many patients being treated for carotid and vertebral artery dissections with percutaneous angioplasty and stent deployment. Although the treatment of dissections is generally well tolerated and the radiographic results are impressive, most dissections heal spontaneously and the associated aneurysms never rupture and rarely cause delayed ischemic symptoms. Surgical treatment of dissections, consisting of an in situ interposition graft or extracranial-intracranial bypass, is indicated only for those patients with persistent symptoms refractory to maximal medical therapy who are not candidates for endovascular treatment.

ISSN:0268-4705    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Tissue Doppler echocardiography (TDE) is a relatively recent addition to the diagnostic ultrasonographic examination. This is similar to routine Doppler ultrasonography to assess blood flow, but technologic features focus on lower velocity frequency shifts. Two techniques are used to assess myocardial function: pulsed TDE and color-coded TDE. A great deal of data has been generated on TDE over the last 5 years, and this review allows for only a small portion of these emerging data to be discussed. One clinical application is to assess peak systolic mitral annular velocity from the apical windows as an index of global ventricular function. The six-site average for peak systolic mitral annular velocity by the color-coded TDE method of greater than 5.4 cm/sec is predictive of an ejection fraction greater than 50% with an 88% sensitivity and a 97% specificity. An emerging application is to use pulsed-TDE to assess ventricular filling pressures. The mitral annular to inflow ratio (E/Ea) greater than 10 is predictive of a mean pulmonary capillary wedge pressure greater than 15 mm Hg with a 92% sensitivity and 80% specificity. Another application is to use peak early diastolic velocity to help differentiate constrictive pericarditis from restrictive cardiomyopathy. Peak early diastolic velocity is blunted with restrictive cardiomyopathy and preserved with constrictive pericarditis. These are just a few of the many evolving clinical applications of this new quantitative diagnostic ultrasonographic method.

ISSN:0268-4705    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Image artifacts, especially those caused by photon attenuation, commonly affect the specificity of cardiac SPECT perfusion imaging. Although often suspected by characteristic patterns identified in female and male patients respectively, the widely variable body habitus of individual patients are associated with unpredictable variations in tissue attenuation. The accuracy of PET perfusion imaging has long benefited from correction methods for soft tissue attenuation. This paper reviews recent developments in attenuation correction methods for cardiac SPECT perfusion imaging. Several commercial methods are now available. Initial reports indicate these methods have varied greatly in their clinical success. Some methods have demonstrated significant improvements. However, others have created more artifacts than they have cured. Recent developments suggest very significant clinical advantages can be achieved with robust, well-validated methods for attenuation corrected SPECT in the diagnostic evaluation of coronary heart disease, high risk coronary disease, and women.

ISSN:0268-4705    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Electromechanical endocardial mapping of the heart using a nonfluoroscopic catheter-based system is a new imaging modality that has been studied recently in the experimental setting as well as in patients. Besides its original application in the diagnosis and treatment of various cardiac arrhythmias, it has also been used as an investigational tool for assessing left ventricular function and viability. Finally, the mapping system may be a valuable platform for direct myocardial revascularization using either laser treatment or injection of pharmacologic agents.

ISSN:0268-4705    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0268-4705    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

A low level of high-density lipoprotein (HDL) cholesterol is an important risk factor for coronary heart disease. Levels of HDL cholesterol and composition of HDL subclasses in plasma are regulated by many factors, including apolipoproteins, lipolytic enzymes, lipid transfer proteins, receptors, and cellular tansporters. Reverse transport of cholesterol from cells of the arterial wall to the liver is an important mechanism by which HDL exerts its anti-atherogenic properties. Enhancement of reverse cholesterol transport is considered as a potential target for anti-atherosclerotic drug therapy. It is suggested, however, that the serum level of HDL cholesterol does not necessarily reflect the efficacy of reverse cholesterol transport.

ISSN:0268-4705    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Oxidized low density lipoproteins (LDLs) are believed to be the most atherogenic form of LDL. However, although a number of experimental data support this concept, the protective role of antioxidants that may prevent LDL oxidation in atherosclerosis is only partially confirmed by studies in humans. Observational and epidemiologic data as well as randomized trials failed to provide clear-cut indications because of mixed results on the protective role of antioxidants against cardiovascular diseases. In spite of the lack of a general consensus, recent data reinforce the concept that a regular intake of antioxidants present in food blocks the progression of atherosclerosis and that the reduced oxidisability of LDL may represent a good marker to follow the action of antioxidants. When it becomes possible to monitor the efficacy of any antioxidant therapy with validated markers of oxidation, the potential influence of vitamins and antioxidants on coronary artery disease will eventually be resolved.

ISSN:0268-4705    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

Because the main cause of death in patients with established coronary heart disease (CHD) is sudden cardiac death (SCD), physicians should develop specific strategy, including dietary changes, to prevent it. In the long term, reduction of the diet-dependent chronic risk factors of CHD, hypercholesterolemia, hypertension, and diabetes, is also important. The association of the cardioprotective effects of the Mediterranean diet (through various mechanisms, likely including the prevention of SCD) with those expected from the reduction of blood lipids and blood pressure and a better control of diabetes (in addition to its gastronomic appeal) renders this dietary pattern extremely attractive for public health purposes. Experimental and epidemiologic studies, as well as randomized trials, clearly demonstrated that n-3 fatty acids reduce the risk of SCD in CHD patients. Their use is now encouraged either as supplements or as part of a Mediterranean-type diet.

ISSN:0268-4705    

出版商:OVID    

年代:2000

数据来源: OVID