Cardiovascular clinics最新文献

Since the first attempt at surgical therapy for VT, much progress has been made in developing techniques for both localization of arrhythmogenic regions as well as their removal or alteration. In the setting of previous myocardial infarction, surgery for VT has evolved from an experiment/last resort procedure to the treatment of choice in many cases, yielding complete freedom from arrhythmia recurrence without adjunctive antiarrhythmic drugs in up to three quarters of operative survivors. Remaining issues in this field include (1) further reduction of operative mortality, perhaps by more careful patient selection (and use of alternative forms of therapy in those judged to be too high risk); (2) better and more accurate mapping techniques to enhance the antiarrhythmic efficacy of surgery; and (3) development of more effective procedures to deal with VT in the setting of cardiomyopathy. Judging from the progress made in the last decade and a half in this field, surgery for VT in many pathologic settings may take on a greater role in the future as further refinements in techniques are realized.

The projected growth of the elderly population in the United States in the coming years underlines the importance of assuring that the quality of life for older persons is maintained. Because CHD is prevalent in this population, measures for preventing disease as well as for optimizing the abilities of those with disease will assume greater significance. Exercise training is a key component in achieving and maintaining optimal capacities in the elderly cardiac and noncardiac populations. These groups can safely undergo exercise training with proper screening and program design. Modifications in the components of the exercise prescription (i.e., frequency, intensity, duration, and activity mode) must be individualized according to the abilities, needs, and goals of each person. Risk factors for CHD still prevail in the elderly, although the predictive value of some risk factors may change with age. For this reason, efforts to control risk factors in older individuals should still be effective in reducing risk from CHD. Dietary modification, weight control, blood pressure control, smoking cessation, and endurance exercise training are several of the interventions used in concert to control risk for CHD.

Cardiomyopathies are an important cause of congestive heart failure in the elderly, and the magnitude of the problem is compounded by changing population demographics and the frequency of congestive heart failure in the elderly. Although the data are far from complete, differences in the clinical presentations and natural history of the cardiomyopathies in older and younger patients are becoming more clearly appreciated. Dilated cardiomyopathy (DCM) is clearly more common than previously appreciated, and elderly patients have a worse prognosis than their younger counterparts with this disease. The medical management of DCM is often more difficult in the elderly, and the problem is compounded by the relatively infrequent use of cardiac transplantation as a therapeutic option. Hypertrophic cardiomyopathy is also more common than previously appreciated, and changes in left ventricular structure often create difficulties in differentiating pathologic states from physiologic. Fortunately, the prognosis for HOCM is more favorable in the elderly than in younger patients and may be partly accounted for by the different structure of the left ventricle. If needed, surgery is an option for elderly patients with medically refractory HOCM, but particular attention must be paid to the presence and severity of associated cardiovascular disease. Restrictive cardiomyopathy with diastolic dysfunction is increasingly recognized as a cause of congestive heart failure. The differentiation from systolic dysfunction is crucial, because the treatments are so markedly different. Age-related changes in diastolic function are becoming more apparent and better characterized, but standardization of age-related "normal" values is still not available. The diagnosis of restrictive heart disease should stimulate a search for an underlying cause, inasmuch as restrictive cardiomyopathy remains a diagnosis of exclusion. Advances in noninvasive imaging have led to a resurgence of interest and have enhanced our knowledge of the cardiomyopathies. Further investigation should proceed in conjunction with studies aimed at defining the characteristics and variables of "normal" aging. For the present, the enigmatic, poorly identified "cardiomyopathies" remain a problem for both young and old.