Hypertension as a hemodynamic disease: The role of impedance cardiography in diagnostic, prognostic, and therapeutic decision making

Hypertension is the most common cardiovascular disease, affecting approximately 60 million Americans. Despite the importance of this condition, only the minority of patients are appropriately identified and treated to reach recommended blood pressure (BP) goals. Although historically defined as an elevation of BP alone, hypertension is characterized by abnormalities of cardiac output, systemic vascular resistance, and arterial compliance. These hemodynamic aspects of hypertension have implications for diagnosis, risk stratification, and treatment. Impedance cardiography (ICG) has emerged as a unique and highly accurate noninvasive tool that is used to assess hemodynamic parameters. Measurement of the various hemodynamic components using ICG in those with hypertension allows more complete characterization of the condition, a greater ability to identify those at highest risk, and allows more effectively targeted drug management. This article reviews the importance of hemodynamic factors in hypertension and the evolving role of ICG technology in the assessment and management of this important cardiovascular condition. Am J Hypertens 2005;18:S2–26S © 2005 American Journal of Hypertension, Ltd.