tailieunhanh - Ebook Essential echocardiography - A companion to braunwald’s heart disease: Part 2

Part 2 book “Essential echocardiography - A companion to braunwald’s heart disease” has contents: Restrictive and infiltrative cardiomyopathies, echocardiography in assessment of cardiac synchrony, echocardiography in assessment of ventricular assist devices, stress echocardiography and echo in cardiopulmonary testing, and other contents. | 24 Restrictive and Infiltrative Cardiomyopathies Vikram Agarwal, Rodney H. Falk INTRODUCTION Restrictive cardiomyopathy (RCM) refers to either an idiopathic or a systemic myocardial disorder in the absence of underlying atherosclerotic coronary artery disease, valvular disease, congenital heart disease, or systemic hypertension, which is characterized by abnormal left ventricular filling, and is associated with normal or reduced left ventricle (LV) and right ventricle (RV) volumes and The term is not precise, but it incorporates infiltrative and fibrotic cardiac pathology, which are dealt with in this chapter. While the majority of patients with infiltrative and fibrotic cardiomyopathies develop a restrictive filling pattern, especially in the later stages of the disease, it is important to differentiate the pathology from a restrictive filling pattern, which can be associated with other types of heart disease, such as dilated cardiomyopathy. In patients with dilated cardiomyopathy the restrictive filling pattern is often a reversible phenomenon, related to worsening heart failure, and morphologically the ventricle is dilated, usually with severe reduction in ejection fraction. Although the clinical presentation of RCM may be similar to dilated cardiomyopathy, the nondilated, stiff ventricles often result in highly sodium-sensitive heart failure symptoms, associated in the late stage of the disease with a low cardiac output due to the small stroke volume. Because of the restriction to diastolic filling and an associated impaired ability to augment cardiac output at higher heart rates, these patients may also present with symptoms of exercise intolerance. Diastolic dysfunction in the presence of preserved left ventricular ejection fraction (LVEF) is the key component of pathophysiology of RCM. Initial stages of RCM demonstrate preserved LVEF with noncompliant walls that impair the normal diastolic filling of the ventricle. This restriction can be .