Nonuniformity: a physiologic modulator of contraction and relaxation of the normal heart

Nonuniformity of mechanical performance is inherent to the multicellular nature and specific geometry and configuration of the ventricle of the heart. Although the concept of nonuniformity of the diseased heart is not new, ventricular function and the performance of the heart as a muscular pump cannot be understood unless nonuniform behavior is taken into account, even under normal conditions. Along with the loading conditions throughout the cardiac cycle and the time courses of activation and inactivation, the nonuniform behavior of load and of activation and inactivation in space and in time constitutes a third important determinant of mechanical performance and efficiency of the ventricle during both contraction and relaxation. Hence, a triad (load, activation-inactivation, nonuniformity) of controls regulates systolic function of the normal ventricle. In the diseased heart, even when loading and activation-inactivation are normal, the modulating role played by this nonuniformity can become imbalanced because of abnormal cavity size or shape or because of regional dysfunction. Such an imbalance would diminish external efficiency (the ratio of work performed to oxygen utilized) of the ventricle and result in incoordinate contraction and relaxation. These abnormalities, in turn, could exacerbate manifest cardiac failure.

This article has been cited by other articles:

				H. F. Choi, F. E. Rademakers, and P. Claus Left-ventricular shape determines intramyocardial mechanical heterogeneity Am J Physiol Heart Circ Physiol, December 1, 2011; 301(6): H2351 - H2361. [Abstract] [Full Text] [PDF]

				D. L. Brutsaert Cardiac failure: quo vadis? Eur J Heart Fail, August 1, 2010; 12(8): 785 - 788. [Full Text] [PDF]

				F. Dorri, P. F. Niederer, P. P. Lunkenheimer, and R. H. Anderson The architecture of the left ventricular myocytes relative to left ventricular systolic function Eur J Cardiothorac Surg, February 1, 2010; 37(2): 384 - 392. [Abstract] [Full Text] [PDF]

				Q. Ciampi, B. Petruzziello, M. D. Porta, S. Caputo, V. Manganiello, C. Astarita, and B. Villari Effect of intraventricular dyssynchrony on diastolic function and exercise tolerance in patients with heart failure Eur Heart J Cardiovasc Imaging, December 1, 2009; 10(8): 907 - 913. [Abstract] [Full Text] [PDF]

				D. P. Strum and M. R. Pinsky Modeling Ischemia-Induced Dyssynchronous Myocardial Contraction Anesth. Analg., October 1, 2006; 103(4): 846 - 853. [Abstract] [Full Text] [PDF]

				P. P. Lunkenheimer, K. Redmann, P. Westermann, K. Rothaus, C. W. Cryer, P. Niederer, and R. H. Anderson The myocardium and its fibrous matrix working in concert as a spatially netted mesh: a critical review of the purported tertiary structure of the ventricular mass Eur J Cardiothorac Surg, April 1, 2006; 29(Supplement_1): S41 - S49. [Abstract] [Full Text] [PDF]

				H. C. Coghlan, A. R. Coghlan, G. D. Buckberg, and J. L. Cox 'The electrical spiral of the heart': its role in the helical continuum: The hypothesis of the anisotropic conducting matrix Eur J Cardiothorac Surg, April 1, 2006; 29(Supplement_1): S178 - S187. [Abstract] [Full Text] [PDF]

				J. J. Schreuder, F. Maisano, A. Donelli, J. R.C. Jansen, P. Hanlon, J. Bovelander, and O. Alfieri Beat-to-Beat Effects of Intraaortic Balloon Pump Timing on Left Ventricular Performance in Patients With Low Ejection Fraction Ann. Thorac. Surg., March 1, 2005; 79(3): 872 - 880. [Abstract] [Full Text] [PDF]

				P. P. Lunkenheimer, K. Redmann, and R. H. Anderson The architecture of the ventricular mass and its functional implications for organ-preserving surgery Eur J Cardiothorac Surg, February 1, 2005; 27(2): 183 - 190. [Abstract] [Full Text] [PDF]

				J. J. Schreuder, A. Castiglioni, F. Maisano, P. Steendijk, A. Donelli, J. Baan, and O. Alfieri Acute decrease of left ventricular mechanical dyssynchrony and improvement of contractile state and energy efficiency after left ventricular restoration J. Thorac. Cardiovasc. Surg., January 1, 2005; 129(1): 138 - 145. [Abstract] [Full Text] [PDF]

				J. Celutkiene, G. R Sutherland, A. Laucevicius, D. Zakarkaite, A. Rudys, and V. Grabauskiene Is post-systolic motion the optimal ultrasound parameter to detect induced ischaemia during dobutamine stress echocardiography? Eur. Heart J., June 1, 2004; 25(11): 932 - 942. [Abstract] [Full Text] [PDF]

				P. Steendijk, S. A. F. Tulner, J. J. Schreuder, J. J. Bax, L. van Erven, E. E. van der Wall, R. A. E. Dion, M. J. Schalij, and J. Baan Quantification of left ventricular mechanical dyssynchrony by conductance catheter in heart failure patients Am J Physiol Heart Circ Physiol, February 1, 2004; 286(2): H723 - H730. [Abstract] [Full Text] [PDF]

				N. H. Andersen, S. H. Poulsen, K. Helleberg, P. Ivarsen, S. T. Knudsen, and C. E. Mogensen Impact of Essential Hypertension and Diabetes Mellitus on Left Ventricular Systolic and Diastolic Performance Eur Heart J Cardiovasc Imaging, December 1, 2003; 4(4): 306 - 312. [Abstract] [Full Text] [PDF]

				H. Oxenham and N. Sharpe Cardiovascular aging and heart failure Eur J Heart Fail, August 1, 2003; 5(4): 427 - 434. [Abstract] [Full Text] [PDF]

				C. G. Fonseca, H. C. Oxenham, B. R. Cowan, C. J. Occleshaw, and A. A. Young Aging alters patterns of regional nonuniformity in LV strain relaxation: a 3-D MR tissue tagging study Am J Physiol Heart Circ Physiol, July 11, 2003; 285(2): H621 - H630. [Abstract] [Full Text] [PDF]

				M. V. Podgoreanu, G. N. Djaiani, E. Davis, B. Phillips-Bute, and J. P. Mathew Quantitative Echocardiographic Assessment of Regional Wall Motion and Left Ventricular Asynchrony with Color Kinesis in Cardiac Surgery Patients Anesth. Analg., May 1, 2003; 96(5): 1294 - 1300. [Abstract] [Full Text] [PDF]

				C. Pislaru, M. Belohlavek, R. Y. Bae, T. P. Abraham, J. F. Greenleaf, and J. B. Seward Regional asynchrony during acute myocardial ischemia quantified by ultrasound strain rate imaging J. Am. Coll. Cardiol., March 15, 2001; 37(4): 1141 - 1148. [Abstract] [Full Text] [PDF]

				W. F. Kerwin, E. H. Botvinick, J. W. O'Connell, S. H. Merrick, T. DeMarco, K. Chatterjee, K. Scheibly, and L. A. Saxon Ventricular contraction abnormalities in dilated cardiomyopathy: effect of biventricular pacing to correct interventricular dyssynchrony J. Am. Coll. Cardiol., April 1, 2000; 35(5): 1221 - 1227. [Abstract] [Full Text] [PDF]

				S. U Sys, G. W De Keulenaer, and D. L Brutsaert Physiopharmacological evaluation of myocardial performance: how to study modulation by cardiac endothelium and related humoral factors? Cardiovasc Res, July 1, 1998; 39(1): 136 - 147. [Full Text] [PDF]

				G.A. Ng, S. M Cobbe, and G. L Smith Non-uniform prolongation of intracellular Ca2+ transients recorded from the epicardial surface of isolated hearts from rabbits with heart failure Cardiovasc Res, February 1, 1998; 37(2): 489 - 502. [Abstract] [Full Text] [PDF]

				H. Kondo, T. Masuyama, K. Ishihara, T. Mano, K. Yamamoto, J. Naito, R. Nagano, S. Kishimoto, J. Tanouchi, M. Hori, et al. Digital Subtraction High-Frame-Rate Echocardiography in Detecting Delayed Onset of Regional Left Ventricular Relaxation in Ischemic Heart Disease Circulation, January 15, 1995; 91(2): 304 - 312. [Abstract] [Full Text]

				R. L. Popp `High Time' for Noninvasive Assessment of Regional Ventricular Diastolic Ischemic Dysfunction Circulation, January 15, 1995; 91(2): 552 - 554. [Full Text]