Open AccessEvaluation of diuretic therapy by impedance cardiography in acute myocardial infarction
Author(s) -
Gabriel S.,
Ekelund L. G.,
OrÖ L.
Publication year - 1980
Publication title -
clinical cardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.263
H-Index - 72
eISSN - 1932-8737
pISSN - 0160-9289
DOI - 10.1002/clc.4960030409
Subject(s) - medicine , furosemide , impedance cardiography , diuretic , cardiology , heart failure , myocardial infarction , stroke volume , cardiac output , hemodynamics , ejection fraction
Changes in transthoracic electrical impedance (TEI) were recorded in 20 patients with acute myocardial infarction before, during, and 60 min after intravenous administration of furosemide (Impugan®). The major change was an increase in TEI (Z 0 ) (6.2%, p<0.001). The mean impedance stroke volume (n = 10) decreased by 7.8% (p<0.05) while the mean impedance cardiac output (n = 10) decreased by 6.3% (p>0.05). Heart rate and blood pressure remained unchanged. It was possible to differentiate between two types of TEI changes after furosemide. In 10 patients there was an early and rapid increase in Z 0 (type A), while the rest of the patients showed a decreased or unchanged Z 0 followed by a slow increase (type B). The line describing the mean Z 0 change in type A was significantly higher than that of type B and fell outside ±2 SEM of the line describing the mean Z 0 change found in five normal subjects (type C). The Z 0 change in type B was similar to that in type C. It is assumed that Z 0 change in type A may represent patients with an increased amount of extravascular fluid (heart failure), while the change in type B represents patients without heart failure. This assumption is based on the difference in dependency of TEI on extravascular volume versus intravascular volume changes. It is suggested that the impedance method may be used as a simple noninvasive method to assess the effect of diuretic therapy and may have the value of detecting extravascular thoracic fluids in acute myocardial infarction.