Impedance cardiography as a noninvasive technique for atrioventricular interval optimization in cardiac resynchronization therapy.

Introduction: Impedance cardiography (IC) and Doppler echocardiography (DE) are two noninvasive methods to evaluate hemodynamics in patients with dual-chamber pacemakers. The aim of the present study was to compare both techniques in respect to their ability of AV-interval optimization in cardiac resynchronization therapy (CRT) based on cardiac output (CO) measurements.