Cardiomyopathy etiology

Cardiomyopathy A general diagnostic term designating primary myocardial disease, often of obscure or unknown etiology. [EU]... 

The results of MADIT II were met with some skepticism, but later confirmed by the recent Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) [24]. This study evaluated the benefit of ICD therapy versus amiodarone or placebo as primary prevention in over 2,500 patients with stable NYHA class II or III heart failure and EF < 35%, without the requirement for NSVT or EPS. Patients with both ischemic and nonischemic etiologies for cardiomyopathy were included. Over a follow-up of 4 years, there was no benefit of amiodarone over placebo for overall mortality, but ICD therapy resulted in a significant 23% reduction in overall mortality [p = 0.007] (Fig. 3.5). The benefit of ICD therapy was comparable for ischemic and nonischemic cardiomyopathy. 

Secondary mitral regurgitation can be a consequence of intraventricular conduction delay. Secondary mitral regurgitation is a common accompaniment of dilated cardiomyopathy of ischemic etiology. Intraventricular conduction delays can create or exacerbate mitral regurgitation by causing a lack of coordination of the papillary muscles [95]. The geometry of the mitral papillary muscles places one near... 

To date, proteomic investigations into human heart disease have centered on dilated cardiomyopathy (DCM). DCM is a disease of unknown etiology, characterized by impaired systolic function resulting in heart failure. Known contributory factors of DCM are viral infections, cardiac-specific autoantibodies, toxic agents, genetic factors, and sustained alcohol abuse. As many as 100 cardiac proteins... 

Tanaka T, Sohmiya K, Kawamura K Is CD36 d ciowy an etiology of hoeditary hypeftro c cardiomyopathy . J Mot Cell Cardiol 29 121-127,1997... 

Diastohc dysfunction plays a role in the presentation of some types of cardiomyopathy. The cardiomyopathies represent a variety of diseases affecting the myocardium in either a diffuse or multifocal manner that frequently results in HE The terminology and classification used for the cardiomyopathies are confusing owing to overlap among the diseases and/or classification schemes. Cardiomyopathies sometimes are defined according to etiology or as primary or secondary... 

Heart failure affects an estimated 4.9 million Americans, and approximately 400,000 new case are diagnosed each year (see Chap. 14). Cardiac transplant candidates typically are patients with end-stage heart failure who have New York Heart Association (NYHA) class III or IV symptoms despite maximal medical management and have an expected 1 -year mortality risk of 25% or greater without a transplant. Idiopathic cardiomyopathy and ischemic heart disease account for heart failure in almost 90% heart transplant recipients. Other less common etiologies include valvular disease (4%), retransplantation for graft atherosclerosis or dysfunction (2%), and congenital heart disease (1.5%). 

Class lib indications for an ICD (1) Patients optimally managed with New York Heart Association Functional Class I heart failure and nonischemic cardiomyopathy who have a left ventricular ejection fraction <0.35. (2) Syncope of unclear etiology and ECG evidence of Brugada syndrome. (3) Patients with congenital long QT interval syndrome who have reasonable expectation of survival. 

In a clinical report based on cardiac biopsy samples obtained from surgery patients, antimony levels were found to be greatly elevated (over 10,000 times) in myocardial compared to non-cardiac muscle samples from patients with idiopathic dilated cardiomyopathy (Frustaci et al. 1999). Other studies have shown that antimony may effect cardiac electrolytes and cardiac calcium currents (Kuryshev et al. 2006). More studies are needed to define the etiologic role antimony may play in cardiovascular disease and associated metabolic pathways, and if those with higher exposure to antimony are more at risk for diseases of the cardiovascular system. 

Candidates for transplantation have refractory heart failure with marked left ventricular decompensation due to a variety of etiologies including coronary artery disease (45%) cardiomyopathy (45%) - idiopathic, hypertensive, peripartum, or viral valvular heart disease (3%-4%) and congenital heart disease (2%) (Taylor et al. 2004 Win-KEL et al. 1999). Candidates are typically less than 65 years of age (although older patients have been transplanted at some centers) and have an estimated 2-year survival of less than 60% without transplantation (Kirklin et al. 2004). 

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