Summary
Changes in left ventricular myocardial wall thickness (MWT) were studied in open-chest dogs using a specially designed strain gauge device. The total systolic increase in MWT was 10%, of which about 30% occurred during the isovolumic phase of contraction. These values are lower than those obtained with cineradiographic techniques. A possible explanation for this divergency is discussed. Calculation of MWT changes showed that increases between 7% and 18% are required to eject resting stroke volumes.
Intravenous injections of isoprenaline showed a log dose-dependent augmentation of the total increase in MWT during systole. Coronary artery occlusion resulted in a fall in the total systolic MWT increase and a decrease in MWT at the end of diastole, which can both be explained by an increase in left ventricular end-diastolic volume. The temporary rise in total systolic MWT increase over the control value, following release of a prolonged occlusion, disappeared when an induced coronary artery stenosis had abolished diastolic reactive hyperemia. This indicates a relationship between coronary blood flow and the extent of total MWT increase in systole.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bove, A. A.: Radiographic evaluation of dynamic geometry of the left ventricle. J. appl. Physiol.31, 227–234 (1971).
Bove, A. A., Lynch, P. R.: Measurements of canine left ventricular performance by cineradiography of the heart. J. appl. Physiol.29, 877–883 (1970).
Brutsaert, D. L., Claes, U. A., Sonnenblick, E. H.: Effects of abrupt loading alterations on force-velocity-length and time relations during isotonic contractions of the heart muscle: Load clamping. J. appl. Physiol.216, 319–330 (1971).
Burns, J. W., Covell, J. W., Myers, R., Ross, J., Jr.: Comparison of directly measured left ventricular wall stress and stress calculated from geometric reference figure. Circulat. Res.28, 611–621 (1971).
Charbon, G. A., Reneman, R. S.: The effects of β-receptor agonists and antagonists on regional blood flow. Europ. J. Pharmacol.9, 21–26 (1970).
Cothran, L. N., Bowie, W. C., Hinds, J. E., Hawthorne, E. W.: Left ventricular wall thickness changes in unanaesthetized horses. In: Factors influencing myocardial contractibility. Ed. by R. D. Tanz, F. Kavaler, G. Roberts. New York: Academic Press 1967.
Eber, L. M., Greenber, H. M., Cooke, J. M., Gorlin, R.: Dynamic changes in left ventricular free wall thickness in the human heart. Circulation39, 455–464 (1969).
Feigl, E. O., Fry, D. L.: Myocardial mural thickness during the cardiac cycle. Circulat. Res.14, 541–545 (1964).
Guntheroth, W. G.: Systolic changes in ventricular thickness in intact dogs. (Abstract). Circulation44, 173 (1971).
Hawthorne, E. W.: Instantaneous dimensional changes of the left ventricle in dogs. Circulat. Res.9, 110–119 (1961).
Hawthorne, E. W.: Dynamic geometry of the left ventricle. Amer. J. Cardiol.18, 566–573 (1966).
Hugenholtz, P. G., Kaplan, E., Hull, E.: Determination of left ventricular wall thickness by angiocardiography. Amer. Heart J.78, 513–522 (1969).
Laks, M. M., Garner, D., Swan, H. J. C.: Volumes and compliances measured simultaneously in the right and left ventricles of the dog. Circulat. Res.20, 565–569 (1967).
Meer, J. J., v. d., Jageneau, A. H. M., Reneman, R. S.: Changes in Myocardial Wall Thickness (MWT) in the openchest dog (Abstract). Pflügers Arch.328, 246 (1971).
Meer, J. J., v. d., Reneman, R. S.: An improved technique to induce a standardized functional stenosis of a coronary artery. Europ. Surg. Res.4, 407–410 (1972).
Mitchell, J. H., Wildenthal, K., Mullins, C. B.: Geometrical studies of the left ventricle utilizing biplane cinefluorography. Fed. Proc.28, 1334–1343 (1969).
Ninomiya, I., Wilson, M. F.: Analysis of ventricular dimensions in the unanesthetized dog. Circulat. Res.16, 249–260 (1965).
Noble, I. M., Wyler, J., Milne, E. N. C., Trenchard, D., Guz, A.: Effect of changes in heart rate on left ventricular performance in conscious dogs. Circulat. Res.24, 285–295 (1969).
Ross, J., Jr., Sonnenblick, E. H., Covell, J. W., Kaiser, G. A., Spiro, D.: The architecture of the heart in systole and diastole. Technique of rapid fixation and analysis of left ventricular geometry. Circulat. Res.21, 409–421 (1967).
Rushmer, R. F.: Cardiovascular dynamics. Philadelphia-London: W. B. Saunders Comp. 1971.
Rushmer, R. F., Crystal, D. K., Wagner, C.: The functional anatomy of ventricular contraction. Circulat. Res.1, 162–170 (1953).
Rushmer, R. F., Finlayson, B. L., Nash, A. A.: Shrinkage of the heart in anaesthetized thoracotomized dogs. Circulat. Res.2, 22–27 (1954).
Sandler, H., Dodge, T. H.: Left ventricular tension and stress in man. Circulat. Res.13, 91–102 (1963).
Sandler, H., Ghista, D. N.: Mechanical and dynamic implications of dimensional measurements of the left ventricle. Fed. Proc.28, 1344–1350 (1969).
Tsakiris, A. G., Vandenberg, R. A., Banchero, N., Sturm, R. E., Wood, E. H.: Variations of left ventricular end-diastolic pressure, volume and ejection fraction with changes in outflow resistance in anesthetized intact dogs. Circulat. Res.23, 213–222 (1968).
Author information
Authors and Affiliations
Additional information
Supported by The Foundation for Medical Research FUNGO.
Rights and permissions
About this article
Cite this article
van der Meer, J.J., Jageneau, A.H.M., Elzinga, G. et al. Changes in myocardial wall thickness (MWT) in open chest dogs. Pflugers Arch. 340, 35–50 (1973). https://doi.org/10.1007/BF00592195
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00592195