Biomaterial Database

Measurement of cardiac output by impedance cardiography under various conditions. 1979

P Boer, and J C Roos, and G G Geyskes, and E J Mees

The suitability of impedance cardiography as a method to follow changes in cardiac output (CO) was investigated by comparing it with thermodilution and by measurements in conditions with predictable effects on CO. The correlation between absolute CO values obtained by impedance and thermodilution techniques was moderate (r = 0.61), but the percentage changes showed a good correlation (r = 0.84). Head-up tilting decreased CO by 25% in 5 normal subjects. Bloodletting in three subjects caused a 20% decrease, reinfusion in one subject a 16% increase. Occlusion of artificial large flow arteriovenous shunts in 6 dialysis patients caused a 12% decrease in CO, whereas the effect was less with moderate and absent with small flow shunts. Ultrafiltration caused a 28% decrease in two dialysis patients. In 20 hypertensive patients CO dropped 25% after salt depletion; propranolol administered intravenously gave a 15% decrease (n = 13), diazoxide intravenously a 30% increase (n = 6). It is concluded that, provided conditions are strictly defined, impedance cardiography is a reproducible method and suitable for the measurement of intrapatient changes in cardiac output.

UI	MeSH Term	Description	Entries
D006973	Hypertension	Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.	Blood Pressure, High,Blood Pressures, High,High Blood Pressure,High Blood Pressures
D007674	Kidney Diseases	Pathological processes of the KIDNEY or its component tissues.	Disease, Kidney,Diseases, Kidney,Kidney Disease
D008297	Male		Males
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D010992	Plethysmography, Impedance	Recording changes in electrical impedance between electrodes placed on opposite sides of a part of the body, as a measure of volume changes in the path of the current. (Stedman, 25th ed)	Rheography,Impedance Plethysmography,Impedance Plethysmographies,Plethysmographies, Impedance,Rheographies
D011187	Posture	The position or physical attitude of the body.	Postures
D002248	Carbon Monoxide	Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)	Monoxide, Carbon
D002302	Cardiac Output	The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).	Cardiac Outputs,Output, Cardiac,Outputs, Cardiac
D002307	Cardiography, Impedance	A type of impedance plethysmography in which bioelectrical impedance is measured between electrodes positioned around the neck and around the lower thorax. It is used principally to calculate stroke volume and cardiac volume, but it is also related to myocardial contractility, thoracic fluid content, and circulation to the extremities.	Impedance, Transthoracic,Plethysmography, Impedance, Transthoracic,Impedance Cardiography,Impedance Plethysmography, Transthoracic,Plethysmography, Transthoracic Impedance,Transthoracic Impedance Plethysmography,Cardiographies, Impedance,Impedance Cardiographies,Impedance Plethysmographies, Transthoracic,Impedances, Transthoracic,Plethysmographies, Transthoracic Impedance,Transthoracic Impedance,Transthoracic Impedance Plethysmographies,Transthoracic Impedances
D005260	Female		Females