Clinical assessment of ventricular ejection dynamics with and without outflow obstruction

Department of Biomedical Engineering Duke University, School of Engineering, Durham, North Carolina 27706.

With the advent of multisensor micromanometric/velocimetric catheterization, digital angiography and Doppler and color echocardiography, extensive fluid dynamic quantitation is now possible in cardiology. Such high fidelity instantaneous measurements offer the clinician the prospect of identifying phasic changes in ventricular ejection dynamics that may disclose contraction abnormalities before overt muscle or pump failure is manifested. Accordingly, this review provides a basis for interpreting these measurements and a conceptual framework for understanding ventricular ejection dynamics with and without outflow obstruction. Necessary terminology and fluid dynamic background, including properties of flows generated by large transient forces, Euler and unsteady Bernoulli equations and local and convective acceleration gradients, are reviewed first. Physiologic aspects of ejection dynamics and transvalvular and intraventricular gradients without obstruction are discussed. Maximal outflow acceleration, rather than ejection velocity, coincides with the attainment of the early peak of the nonobstructive pressure gradients. These gradients are characteristically even more asymmetric than are the associated ejection velocity signals. Clinical correlations are introduced, beginning with obstructive transvalvular and subvalvular gradients in aortic stenosis and the phenomenon of recovery of pressure loss in the poststenotic dilation. The large obstructive gradients tend to be distinctively symmetric, as are the ejection waveforms, whose configuration they track more or less closely, depending on the degree of stenosis and relative preponderance of convective effects throughout ejection. Pitfalls in some unwarranted applications of the "simplified Bernoulli equation" are pointed out. Polymorphic gradients of hypertrophic cardiomyopathy, reflecting dynamically dissimilar intraventricular flow regimes in early, mid and late systole, are examined. Enormous late systolic gradients can be associated with progressive shrinkage of flow passage area and sharp increases in linear velocity while volumetric outflow is diminutive. The concept of ventriculoannular disproportion in dilated ventricles is defined and discussed. The implications of ejection fluid dynamics for systolic ventricular and myocardial loading are examined, and the concept of complementarity and competitiveness between intrinsic and extrinsic load components is introduced. Finally, critical research issues are identified and addressed. The primary emphasis is on using the basic principles of fluid dynamics to better understand ejection in the normal or abnormal human left ventricle and aortic root.(ABSTRACT TRUNCATED AT 400 WORDS)

This article has been cited by other articles:

				E. L. Ritman, A. Pasipoularides, T. Arts, T. Delhaas, P. P. Sengupta, B. K. Khandheria, A. J. Tajik, A. Boussuges, and J. Regnard To the editor: functional imaging(FI) combines imaging datasets and computational fluid dynamics to simulate cardiac flows. J Appl Physiol, September 1, 2008; 105(3): 1015 - 1015. [Full Text] [PDF]

				D. J. Penny, J. P. Mynard, and J. J. Smolich Aortic wave intensity analysis of ventricular-vascular interaction during incremental dobutamine infusion in adult sheep Am J Physiol Heart Circ Physiol, January 1, 2008; 294(1): H481 - H489. [Abstract] [Full Text] [PDF]

				C. Cortina, J. Bermejo, R. Yotti, M. M. Desco, D. Rodriguez-Perez, J. C. Antoranz, J. L. Rojo-Alvarez, D. Garcia, M. A. Garcia-Fernandez, and F. Fernandez-Aviles Noninvasive Assessment of the Right Ventricular Filling Pressure Gradient Circulation, August 28, 2007; 116(9): 1015 - 1023. [Abstract] [Full Text] [PDF]

				J Jimenez-Candil, J Bermejo, R Yotti, C Cortina, M Moreno, J L Cantalapiedra, and M A Garcia-Fernandez Effects of angiotensin converting enzyme inhibitors in hypertensive patients with aortic valve stenosis: a drug withdrawal study Heart, October 1, 2005; 91(10): 1311 - 1318. [Abstract] [Full Text] [PDF]

				R. Yotti, J. Bermejo, M. M. Desco, J. C. Antoranz, J. L. Rojo-Alvarez, C. Cortina, C. Allue, H. Rodriguez-Abella, M. Moreno, and M. A. Garcia-Fernandez Doppler-Derived Ejection Intraventricular Pressure Gradients Provide a Reliable Assessment of Left Ventricular Systolic Chamber Function Circulation, September 20, 2005; 112(12): 1771 - 1779. [Abstract] [Full Text] [PDF]

				J Bermejo The effects of hypertension on aortic valve stenosis Heart, March 1, 2005; 91(3): 280 - 282. [Abstract] [Full Text] [PDF]

				R. Yotti, J. Bermejo, J. C. Antoranz, J. L. Rojo-Alvarez, C. Allue, J. Silva, M. M. Desco, M. Moreno, and M. A. Garcia-Fernandez Noninvasive assessment of ejection intraventricular pressure gradients J. Am. Coll. Cardiol., May 5, 2004; 43(9): 1654 - 1662. [Abstract] [Full Text] [PDF]

				A. Pasipoularides, M. Shu, A. Shah, A. Tucconi, and D. D. Glower RV instantaneous intraventricular diastolic pressure and velocity distributions in normal and volume overload awake dog disease models Am J Physiol Heart Circ Physiol, November 1, 2003; 285(5): H1956 - H1965. [Abstract] [Full Text] [PDF]

				A. Pasipoularides, M. Shu, A. Shah, M. S. Womack, and D. D. Glower Diastolic right ventricular filling vortex in normal and volume overload states Am J Physiol Heart Circ Physiol, April 1, 2003; 284(4): H1064 - H1072. [Abstract] [Full Text] [PDF]

				A. D. Pasipoularides, M. Shu, M. S. Womack, A. Shah, O. von Ramm, and D. D. Glower RV functional imaging: 3-D echo-derived dynamic geometry and flow field simulations Am J Physiol Heart Circ Physiol, January 1, 2003; 284(1): H56 - H65. [Abstract] [Full Text] [PDF]

				A. D. Pasipoularides, M. Shu, A. Shah, and D. D. Glower Right ventricular diastolic relaxation in conscious dog models of pressure overload, volume overload, and ischemia J. Thorac. Cardiovasc. Surg., November 1, 2002; 124(5): 964 - 972. [Abstract] [Full Text] [PDF]

				W. K. Laskey and W. G. Kussmaul Subvalvular Gradients in Patients With Valvular Aortic Stenosis: Prevalence, Magnitude, and Physiological Importance Circulation, August 28, 2001; 104(9): 1019 - 1022. [Abstract] [Full Text] [PDF]

				S. Nakatani, M. S. Firstenberg, N. L. Greenberg, P. M. Vandervoort, N. G. Smedira, P. M. McCarthy, and J. D. Thomas Mitral inertance in humans: critical factor in Doppler estimation of transvalvular pressure gradients Am J Physiol Heart Circ Physiol, March 1, 2001; 280(3): H1340 - H1345. [Abstract] [Full Text] [PDF]

				M. S. Firstenberg, P. M. Vandervoort, N. L. Greenberg, N. G. Smedira, P. M. McCarthy, M. J. Garcia, and J. D. Thomas Noninvasive estimation of transmitral pressure drop across the normal mitral valve in humans: importance of convective and inertial forces during left ventricular filling J. Am. Coll. Cardiol., November 15, 2000; 36(6): 1942 - 1949. [Abstract] [Full Text] [PDF]

				A. Redaelli, F. Maisano, J. J. Schreuder, and F. M. Montevecchi Ventricular motion during the ejection phase: a computational analysis J Appl Physiol, July 1, 2000; 89(1): 314 - 322. [Abstract] [Full Text] [PDF]

				W.A. Schobel, W. Voelker, K.K. Haase, and K.-R. Karsch Extent, determinants and clinical importance of pressure recovery in patients with aortic valve stenosis Eur. Heart J., September 2, 1999; 20(18): 1355 - 1363. [Abstract] [PDF]

				M. V. Sherrid, G. Pearle, and D. Z. Gunsburg Mechanism of Benefit of Negative Inotropes in Obstructive Hypertrophic Cardiomyopathy Circulation, January 13, 1998; 97(1): 41 - 47. [Abstract] [Full Text] [PDF]

				R. A. Levine, G. J. Vlahakes, X. Lefebvre, J. L. Guerrero, E. G. Cape, A. P. Yoganathan, and A. E. Weyman Papillary Muscle Displacement Causes Systolic Anterior Motion of the Mitral Valve : Experimental Validation and Insights Into the Mechanism of Subaortic Obstruction Circulation, February 15, 1995; 91(4): 1189 - 1195. [Abstract] [Full Text]