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Management of congestive heart failure is based on clinical classification of the syndrome as predominately related to left ventricular systolic or diastolic dysfunction. All patients with newly diagnosed or chronic heart failure, which has not been previously evaluated, should undergo a diagnostic evaluation to 1) determine whether cardiac dysfunction is due to systolic or diastolic failure, 2) uncover correctable etiologic factors, 3) determine prognosis, and 4) guide management. Left ventricular systolic dysfunction can be recognized by the presence of a left ventricular ejection fraction less than or equal to 40%. Chronic left ventricular systolic dysfunction is almost always accompanied by evidence by ventricular dilatation evident as an increase in both and end-systolic and end-diastolic volume or dimensions. In all patients with depressed left ventricular ejection fraction, the exclusion of "afterload mismatch," that is the presence of depressed contractile function due to It is particularly important to exclude uncontrolled systolic arterial hypertension, valvular aortic stenosis or aortic regurgitation as reversible causes of left ventricular systolic dysfunction due to "afterload mismatch." Echocardiography is the most efficient and cost effective imaging modality to evaluate left ventricular global and regional function (ejection fraction), chamber dimensions, and presence or absence of co-existing valve disease. Other modalities that can be considered include contrast left ventriculography, radionuclide ventriculography.
Evaluation of LVSD
In the adult patient with congestive heart failure due to left ventricular systolic dysfunction (LVSD), the number one priority is to detect ischemia due to occult coronary artery disease in all patients with unexplained heart failure who are potential candidates for revascularization. This is important because there is a growing body of evidence that both regional and global depression of LVSD can be partially reversed in patients with "hibernating" myocardium related to extensive coronary artery disease. In most cases this can be done with non-invasive stress testing using either exercise or dobutamine stress electrocardiography. If non-invasive stress testing suggests a high probability of underlying coronary artery disease or if non-invasive stress testing is inconclusive in a patient with multiple risk factors for coronary artery, the evaluation should proceed to coronary arteriography. Additional diagnostic studies which should be performed in all patients with chronic failure or newly diagnosed include CBC and urinalysis; electrolytes, glucose, calcium, and albumin levels; thyroid stimulating hormone level. In addition, serum iron and ferritin levels should be measured in male patients with heart failure of unknown etiology. A careful history should always be obtained to assess the possibility of alcohol, cocaine, and/or amphetamines.
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