Measurement of Cardiac Output by Impedance Cardiography in Patients with Myocardial Infarction: Comparative Evaluation of Impedance and Dye Dilution Methods

Abstract

The cardiac output was measured simultaneously by the impedance cardiography and dye dilution methods in 10 patients with acute myocardial infarction 2–3 weeks after admission to the Coronary Care Unit. The impedance cardiac output was on the average 9.7% higher than the dye dilution cardiac output. The repro-ducibility of impedance cardiac output was 4.1%, compared with 5.1% for the dye dilution method. The study showed a satisfactory reliability of impedance in predicting the relative change of cardiac output in response to tilting from the supine to the 30d` head-up position, to a 10d` head-down position, and to the intravenous administration of propranolol.

Key Words:

• Body tilt
• cardiac output
• dye dilution technique
• impedance cardiograph
• myocardial infarction