Abstract
The suitability of the peak value of the first derivative of the thoracic electrical impedance dZ/dtmax has been investigated in dogs as a non-invasive index of changes in myocardial contracility by comparing if with the peak left ventricular dP/dt and the peak values of aortic blood velocity and acceleration. An increase in the inspired halothane concentration was used to produce changes in contracility. In 5 dogs the combined values for the correlation coefficient between dZ/dtmax peak velocity and acceleration were respectively 0.937, 0.954 and 0.950. In 14 out 15 comparisons p<0.001 and in one, p<0.01. On these grounds, dZ/dtmax is proposed as a variable worthy of consideration in patient monitoring.
Article PDF
Similar content being viewed by others
References
Douglas, R., Hill, D.W., Wood, D.G.L.: Methods for the estimation of blood halothane concentrations by gas chromatography. Brit. J. Anaesth.42, 119 (1970)
Furnival, C.M., Linden, R.J., Snow, H.M.: Inotropic changes in the left ventricle: The effect of changes in heart rate, aortic pressure and end-diastolic pressure. J. Physiol. (Lond.)211, 359 (1970)
Geddes, L.A., da Costa, C.P.: The specific resistance of canine blood at body temperature. IEEF Trans. BME20, 51 (1973)
Gersh, B.J., Prys-Roberts, C., Reuben, S.R., Baker, A.B.: The relationship between depressed myocardial contractility and the stroke output of the canine heart during halothane anaesthesia. Brit. J. Anaesth.42, 560 (1970)
Gil-Rodriquez, J.A., Hill, D.W., Lundberg, S.: The correlation between haemodynamic changes and arterial blood halothane concentrations during halothane-nitrous oxide anesthesia in the dog. Brit. J. Anaesth.43, 1043 (1971)
Heather, L.W.: A comparison of cardiac output values by the impedance cardiograph and dye dilution technique in cardiac patients. Progress Report No. NA 59-4500 (National Aeronautics and Space Administration, Manned Spacecraft Centre, Houston, Texas) 247 (1969)
Hill, D.W., Mohapatra, S.N., Welham, K.C., Stevenson, Margaret L.: The effect of a progressive decrease in the circulating blood volume of the dog on the transthoracic impedance. Europ. J. intens. Care Med.2, 119 (1976)
Hughes, R.: The haemodynamic effects of halothane in dogs Brit. J. Anaesth.45, 418 (1973)
Kubicek, W.G., Karnegis, J.N., Patterson, R.N., Witsoe, D.A., Mattson, R.H.: Development and evaluation of an impedance cardiac output system. Aerospace Med.37, 1208 (1966)
Kubicek, W.G., Kottke, F.J., Ramos, M.U., Patterson, R.P., Witsoe, D.A., Labree, J.W., Remole, W., Layman, T.E., Schoening, H., Garamela, J.T.: The Minnesota impedance cardiograph — theory and applications. Biomed. Engineer.9, 410 (1974)
Lowe, H.J.: Flame ionization detection of volatile organic anesthetics in blood, gases and tissues. Anesthesiology25, 808 (1964)
Mason, D.T.: Usefulness and limitations of the rate of rise of intraventricular pressure (dP/dt) in the evaluation of myocardial contractility in man. Amer. J. Cardiol.23, 516 (1969)
Mason, D.T., Spann, J.F., Zelis, R.: Quantification of the contractile state of the intact human heart. Amer. J. Cardiol.26, 248 (1970)
Mason, D.T., Braunwald, E., Covell, J.W., Sonnenblick, E.H., Ross, J. Jr.: Assessment of cardiac contractility: The relation between the rate of pressure rise and ventricular pressure during isovolumic systole. Circulation44, 47 (1971)
Mirsky, I., Ellison, R.C., Hugenholtz, P.G.: Assessment of myocardial contractility in children and young adults from ventricular pressure recordings. Amer. J. Cardiol.27, 359 (1971)
Mitchell, J.H., Wallace, A.G., Skinner, N.S.: Intrinsic effects of heart rate on left ventricular performance. Amer. J. Physiol.205, 41 (1963)
Mitchell, J.H., Wildenthal, K.: Problems in the measurement of myocardial contractility: Analysis of left ventricular function. Proc. Roy. Soc. Med.65, 542 (1972)
Noble, M.I.M., Trenchard, D., Guz, A.: Measurement and significance of the maximum acceleration of blood from the left ventricle. Circulat. Res.19, 139 (1966)
Patterson, S.W., Piper, H., Starling, E.H.: The regulation of the heart beat. J. Physiol. (Lond.)48, 465 (1914)
Rusy, B.F., Moran, J.E., Fox, S.: The effects of halothane and cyclopropane on the maximum acceleration of left ventricular ejection and the tensio-time index in dogs. Anesthesiology45, 139 (1971)
Sarnoff, S.J., Berglund, E.: Ventricular function 1. Starling's law of the heart studied by means of simultaneous right and left ventricular function curves in the dog. Circulation9, 706 (1954)
Siegel, J.H., Sonnenblick, E.H.: Isometric time-tension relationships as an index of myocardial contractility. Circulat. Res.12, 597 (1963)
Siegel, J.H., Fabian, M., Lankau, C., Levine, M., Cole, A., Nahmad, M.: Clinical and experimental use of thoracic impedance plethysmography in quantifying myocardial contractility. Surgery67, 907 (1970)
Sonnenblick, E.H.: Series elastic and contractile elements in heart muscle: changes in muscle length. Amer. J. Physiol.207, 1330 (1964)
Van den Bos, G.C., Elzinga, G., Westerhof, N., Noble, M.I.M.: Problems in the use of indices of myocardial contractility. Cardiovasc. Res.7, 834 (1973)
Veragut, U.P., Krayenbuhl, H.P.: Estimation and quantification of myocardial contractility in the closed-chest dog. Cardiologia47, 96 (1965)
Wallace, A.G., Skinner, N.S., Mitchell, J.H.: Haemodynamic determinants of the maximal rate of rise of left ventricular pressure. Amer. J. Physiol.205, 30 (1963)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Welham, K.C., Mohapatra, S.N., Hill, D.W. et al. The first derivative of the transthoracic electrical impedance as an index of changes in myocardial contractility in the intact anaesthetised dog. Intensive Care Med 4, 43–50 (1978). https://doi.org/10.1007/BF01683136
Issue Date:
DOI: https://doi.org/10.1007/BF01683136