ISSN:0268-4705    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Abnormal intracellular Ca2+handling plays an important role in the systolic and diastolic dysfunction of heart failure. In recent years, cellular and molecular biologic techniques have enhanced our understanding of the mechanisms responsible for these fundamental changes in excitation-contraction coupling.

ISSN:0268-4705    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

In order to study the pathophysiology of heart failure and the efficacy of new pharmacologic interventions, a large number of animal models have been developed to simulate this complex syndrome. Most of these models were of major surgical trauma, myocardial ischemia, and pharmacologic or toxic depression of cardiac function. Unfortunately, these older models often have major limitations. Newer, relatively noninvasive models have been developed that closely resemble human heart failure. In this review, we briefly discuss new aspects of two of the most interesting and widely used established models of heart failure,ie,myocardial infarction in the rat and chronic rapid pacing, as well as some recently described novel preparations of experimental heart failure.

ISSN:0268-4705    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The importance of neurohormonal factors in the pathogenesis and perpetuation of congestive heart failure has been well known for many years. The decade of the 1980s saw a proliferation of publications regarding neurohormonal factors in congestive heart failure, so that the measurement of the more typical of these substances, such as norepinephrine, renin, and atrial natriuretic factor (ANF), is a frequent accompaniment to studies of physiologic and pharmacologic issues related to the failing heart. The concept of “neurohormonal factors” has traditionally referred to vasoconstrictor or vasodilator substances that can exert an influence on the circulation at a site or sites remote from the source of production. Therefore, the substances have traditionally been considered hormones, or endocrine substances, by definition. As described in the following paragraphs, the paracrine andin siturole of these vasoactive substances must now be taken into consideration. The literature that forms the basis of this review covers four aspects of neurohormonal and renal mechanisms in heart failure. First, the expansion of the role of neurohormonal mechanisms into the patient population with asymptomatic or mild left ventricular failure. Second, the difficulties that may arise with assessing the role of a neurohormonal substance, such as an ANF. Third, the important, but difficult-to-quantitate, role of the kidney in congestive heart failure. Fourth,in situactivity of neurohormonal substances, beyond the traditional endocrine role of these substances.

ISSN:0268-4705    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Published clinical data has emphasized the importance of reperfusion in limiting ventricular remodeling and has shown that patients with anterior infarcts are at greater risk of infarct expansion. However, some doubts have been cast on the benefits of late reperfusion, as analysis suggests that it may be associated with increased incidence of myocardial rupture. A great deal of evidence has been published to suggest that changes to the myocardial collagen matrix play an important role in ventricular remodeling. Connections between such disparate studies have been provided by a recent review of the clinical and basic science literature which identified three factors that might limit ventricular remodeling: limitation of infarct size, reduction of ventricular wall stress, and enhancement of scar healing. Consideration of these factors in current and future experiments is likely to enhance our understanding of ventricular remodeling.

ISSN:0268-4705    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Dyspnea, fatigue, and reduced exercise capacity are cardinal features of patients with chronic heart failure. The mechanisms of limitation of exercise capacity are not known. Over the last 10 years there has been increasing use of cardiopulmonary exercise testing to study the pathophysiology of heart failure. Exercise testing in patients with heart failure has revealed little or no correlation between central hemodynamic measurements at rest or during exercise and either exercise capacity or symptoms. Interest has therefore been directed toward changes in the peripheral circulation and in the function of exercising skeletal muscle. Reduced vasodilatory capacity, altered muscle fiber types, and altered muscle biochemistry (studied from muscle biopsies or by31P-NMR spectroscopy) have all been described.

ISSN:0268-4705    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

This review focuses on interesting developments in the area of vasodilator therapy for congestive heart failure. This pharmacologic approach represents the major recent advance in the clinical management of this syndrome. Recent developments include a greater insight into the mechanisms of action of angiotensin-converting enzyme inhibitors. Data are available stressing the importance of bradykinin in this regard. Furthermore, it is now clear that the formation of tissue angiotensin II can be stimulated by many enzymes other than angiotensin-converting enzyme. As this review is being prepared, data are becoming available from seven major trials that will have an impact on the clinical role of angiotensin-converting enzyme inhibitors. Information has appeared on promising new vasodilating drugs, and new data have been published that clarify issues concerning older agents, such as the nitrates and calcium-channel blockers.

ISSN:0268-4705    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The primary cardiac abnormality in patients with congestive heart failure due to a dilated cardiomyopathy is pump failure. Therefore, we intuitively expect that inotropic agents, drugs that increase the contractility of the heart, would be beneficial in patients with heart failure. Because the most potent mechanism for increasing cardiac contractility is the adrenergic pathway, agents have been developed that augment cardiac contractility via stimulation of adrenergic receptors. Alternately, other pharmaceuticals have been developed that interact with more distal sites in the excitation contraction-coupling pathway. However, with the exception of digoxin, no inotropic agents have proven to be of long-term benefit in patients with congestive failure. This review briefly outlines recent observations on the use of new inotropic agents and adrenergic agonists in the treatment of patients with congestive heart failure.

ISSN:0268-4705    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

The neuroendocrine system, and particularly chronic sympathetic nervous system activation, is important in the pathophysiology of heart failure. Clinical studies and an improved understanding of the adverse consequences of excessive sympathetic activation support the beneficial role of β-adrenergic blocking drugs in patients with heart failure. Indirect evidence for a beneficial role of β-adrenergic drugs in heart failure comes from large randomized trials following acute myocardial infarction. Small studies of a new generation of vasodilating β-adrenergic blocking drugs have demonstrated beneficial effects on left ventricular performance and exercise tolerance in heart failure. Larger clinical trials are still required to establish which patients will benefit, and at what stage in the development of congestive heart failure the agents should be introduced.

ISSN:0268-4705    

出版商:OVID    

年代:1991

数据来源: OVID

摘要:

Despite the proven efficacy of powerful diuretics and the angiotensin-converting enzyme inhibitors for the treatment of heart failure, these agents still fail to control the symptoms and signs of the diseases in many patients and to prevent many complications, including arrhythmia and sudden death. This implies that the underlying problem may be immune to remedy and only may be ameliorated, or that understanding of the condition is incomplete. The latter is certainly true, although the former is not precluded. Consideration should be given to alternative modes of therapy for patients with heart failure. Some treatments may not appear rational (corenzyme Q10 or β-receptor antagonists) and others may be applicable only to small groups with specific problems (oxygen therapy, ultrafiltration, skeletal muscle cardiomyoplasty). Other treatments do not tackle the obvious problem (heart failure) but are directed against important secondary problems (thromboembolism, arrhythmias). As the limitations of “conventional” treatment are clarified, it is likely that one or more of several new treatments will become “respectable” and widespread.

ISSN:0268-4705    

出版商:OVID    

年代:1991

数据来源: OVID