Cardiac Disease in Chronic Uremia: Pathogenesis

Cardiomyopathyin chronic uremiaresults from pressure and volume overload. The former causes concentric left ventricular (LV) hypertrophy, results from hypertension and aortic stenosis, and is also associated with diabetes mellitus and anemia. Volume overloadcauses LV dilatation, results from arteriovenous shunting, salt and water overload, and anemia, and is also associated with ischemic heart disease, hypertension, and hypoalbuminemia. Decreased major arterial compliance and an early return of arterial wave reflections are also associated with the extent of LV hypertrophy. Cardiomyopathypredisposes to diastolic and systolic dysfunction. The latter results from myocyte death, and predisposing factors include ischemic heart diseaseand the uremic environment. Ischemic heart diseasemay be atherosclerotic or nonatherosclerotic in origin. Multiple factors contribute to the vascular pathology of chronic uremia, including injury to the vessel wall, dyslipidemia, prothrombotic factors, increased oxidant stress, and hyperhomocysteinemia. Ischemic risk factors include hypertension, LV hypertrophy, hypoalbuminemia, and perhaps hyperparathyroidism. The clinical consequences of cardiomyopathyinclude heart failure, ischemic heart disease, dialysis hypotension, and arrhythmias. The adverse impact of ischemic heart diseaseis probably mediated through the development of cardiac failure.