Heart valve dynamics

During coronary underperfusion, there is downregulation of cytosolic 5'nucleotidase (5NT), mediating AMP hydrolysis to adenosine. The present study tested whether 5NT remains downregulated during more extreme oxidative stress. Rabbit hearts were studied during two sequential periods of coronary underperfusion (90% flow reduction, 30 min.) separated by 20 min. of reperfusion. In the second period, the perfusate gas equilibrium was decreased from the normal 95% 02 to 30% O> In the second period, myocardial lactate production was increased by 20%, compared to the first period, creatine phosphate decreased further (73% vs. 49%), and calculated cytosolic AMP concentration increased to 2.7 gM. Despite the 40% higher AMP concentration, total coronary purine efflux (adenosine + inosine + hypoxanthine) was decreased by nearly 40%, indicating decreased activity of 5NT. In conclusion, even when oxidative stress is increased to extreme levels, coronary underperfusion still produces downregulation of 5NT. (Supported by NIH grants HL51152 and RR01243) 112 SHEAR STRESS MODULATES THE PROTEINASE ACTIVITY OF ENDOTHELIAL CELLS IN PORCINE CAROTID ARTERY H.C. Han, B. S. Conklin, G. Hamilton*, P. R. Girard*, D N. Ku

[1]  I Vesely,et al.  Micromechanics of the fibrosa and the ventricularis in aortic valve leaflets. , 1992, Journal of biomechanics.

[2]  W. Roberts,et al.  Morphologic features of the normal and abnormal mitral valve. , 1983, The American journal of cardiology.

[3]  R. Frater.  Anatomical Rules for the Plastic Repair of a Diseased Mitral Valve , 1964, Thorax.

[4]  M Janier,et al.  Mitral subvalvular apparatus: different functions of primary and secondary chordae. , 1997, Circulation.

[5]  B Wranne,et al.  Tricuspid annular motion. , 1991, Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography.

[6]  H. Torp,et al.  The velocity distribution in the aortic anulus in normal subjects: a quantitative analysis of two-dimensional Doppler flow maps. , 1991, Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography.

[7]  A F Bolger,et al.  Three-dimensional regional dynamics of the normal mitral anulus during left ventricular ejection. , 1996, The Journal of thoracic and cardiovascular surgery.

[8]  Guang-Zhong Yang,et al.  Helical and Retrograde Secondary Flow Patterns in the Aortic Arch Studied by Three‐Directional Magnetic Resonance Velocity Mapping , 1993, Circulation.

[9]  B. Bellhouse,et al.  Fluid mechanics of model normal and stenosed aortic valves. , 1969, Circulation research.

[10]  S. Oyre,et al.  Three-dimensional visualization of velocity profiles in the human main pulmonary artery with magnetic resonance phase-velocity mapping. , 1994, American heart journal.

[11]  R. P. Cochran,et al.  Stress/Strain Characteristics of Porcine Mitral Valve Tissue: Parallel Versus Perpendicular Collagen Orientation , 1992, Journal of cardiac surgery.

[12]  C Uyama,et al.  Mitral annular function assessed by 3D imaging for mitral valve surgery. , 1994, The Journal of heart valve disease.

[13]  R. F. Rushmer,et al.  Movements of the Mitral Valve , 1956, Circulation research.

[14]  K S Kunzelman,et al.  Anatomic basis for mitral valve modelling. , 1994, The Journal of heart valve disease.

[15]  W. Roberts,et al.  The congenitally bicuspid aortic valve. A study of 85 autopsy cases. , 1970, The American journal of cardiology.

[16]  Andrew L. Wit,et al.  Canine Mitral Complex: ULTRASTRUCTURE AND ELECTROMECHANICAL PROPERTIES , 1972, Circulation research.

[17]  P K Paulsen,et al.  Three-dimensional visualization of velocity profiles in the ascending aorta in dogs, measured with a hot-film anemometer. , 1983, Journal of biomechanics.

[18]  W. Roberts,et al.  Detailed anatomy of the normally functioning aortic valve in hearts of normal and increased weight. , 1985, The American journal of cardiology.

[19]  J. Dunmore-Buyze,et al.  A comparison of macroscopic lipid content within porcine pulmonary and aortic valves. Implications for bioprosthetic valves. , 1995, The Journal of thoracic and cardiovascular surgery.

[20]  M E Silverman,et al.  The mitral complex. Interaction of the anatomy, physiology, and pathology of the mitral annulus, mitral valve leaflets, chordae tendineae, and papillary muscles. , 1968, American heart journal.

[21]  S. H. Dixon,et al.  The influence of atrial contraction and mitral valve mechanics on ventricular filling , 1969 .

[22]  J. P. Gilmore,et al.  Influence of atrial contraction and relaxation on closure of mitral valve. Observations on effects of autonomic nerve activity. , 1962, Circulation research.

[23]  Robert H. Anderson,et al.  Location of the coronary arterial orifices in the normal heart , 1997, Clinical anatomy.

[24]  A. Tajik,et al.  Age-related changes in aortic and mitral valve thickness: implications for two-dimensional echocardiography based on an autopsy study of 200 normal human hearts. , 1988, The American journal of cardiology.

[25]  T. Arts,et al.  Stresses in the closed mitral valve: a model study. , 1983, Journal of biomechanics.

[26]  R. Gramiak,et al.  Influence of the timing of atrial systole on mitral valve closure and on the first heart sound in man. , 1970, The American journal of cardiology.

[27]  L. Irving,et al.  Motion of both mitral valve leaflets: a cineroentgenographic study in intact dogs. , 1975, Journal of applied physiology.

[28]  David B. Smith,et al.  The aortic valve microstructure: effects of transvalvular pressure. , 1998, Journal of biomedical materials research.

[29]  W. S. Ring,et al.  Differential collagen distribution in the mitral valve and its influence on biomechanical behaviour. , 1993, The Journal of heart valve disease.

[30]  I Vesely,et al.  Porcine pulmonary and aortic valves: a comparison of their tensile viscoelastic properties at physiological strain rates. , 1995, The Journal of heart valve disease.

[31]  G. Gerosa,et al.  The Pulmonary Valve: Is It Mechanically Suitable for Use as an Aortic Valve Replacement? , 1994, ASAIO journal.

[32]  A. Dean.  THE MOVEMENTS OF THE MITRAL CUSPS IN RELATION TO THE CARDIAC CYCLE , 1916 .

[33]  K S Kunzelman,et al.  Flexible versus rigid ring annuloplasty for mitral valve annular dilatation: a finite element model. , 1998, The Journal of heart valve disease.

[34]  M. Thubrikar,et al.  Patterns of calcific deposits in operatively excised stenotic or purely regurgitant aortic valves and their relation to mechanical stress. , 1986, The American journal of cardiology.

[35]  R. Gramiak,et al.  Echocardiography of the normal and diseased aortic valve. , 1970, Radiology.

[36]  E. Wood,et al.  Influence of sequence of atrial and ventricular systoles on closure of mitral valve. , 1967, Journal of applied physiology.

[37]  J. Seward,et al.  The noninvasive assessment of left ventricular diastolic function with two-dimensional and Doppler echocardiography. , 1997, Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography.

[38]  J. Ross,et al.  Effective Closure of the Mitral Valve without Atrial Systole , 1966, Circulation.

[39]  D R Boughner,et al.  Mechanical properties of human mitral valve chordae tendineae: variation with size and strain rate. , 1975, Canadian journal of physiology and pharmacology.

[40]  G. Christie,et al.  Mechanical properties of porcine pulmonary valve leaflets: how do they differ from aortic leaflets? , 1995, The Annals of thoracic surgery.

[41]  Daniel E. Guyer,et al.  Clinical significance of incomplete tricuspid valve closure seen on two-dimensional echocardiography. , 1984, Journal of the American College of Cardiology.

[42]  E D Wigle,et al.  Morphology of the Human Tricuspid Valve , 1971, Circulation.

[43]  A. Carpentier,et al.  Cardiac valve surgery--the "French correction". , 1983, The Journal of thoracic and cardiovascular surgery.

[44]  S Westaby,et al.  Adult human valve dimensions and their surgical significance. , 1984, The American journal of cardiology.

[45]  N G Pandian,et al.  Volume-rendered three-dimensional dynamic anatomy of the mitral annulus using a transesophageal echocardiographic technique. , 1995, The Journal of heart valve disease.

[46]  N. Schiller,et al.  Descent of the base of the left ventricle: an echocardiographic index of left ventricular function. , 1989, Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography.

[47]  K Kristoffersen,et al.  Cross sectional early mitral flow velocity profiles from colour Doppler. , 1989, British heart journal.

[48]  P. Come,et al.  Tricuspid anular dilatation and failure of tricuspid leaflet coaptation in tricuspid regurgitation. , 1985, The American journal of cardiology.

[49]  E. Wood,et al.  Fixation of the annulus of the mitral valve with a rigid ring. Hemodynamic studies. , 1967, The American journal of cardiology.

[50]  E H Wood,et al.  Roentgen video densitometer study of mitral valve closure during atrial fibrillation. , 1968, Journal of applied physiology.

[51]  Robert A. Levine,et al.  Integrated mechanism for functional mitral regurgitation: leaflet restriction versus coapting force: in vitro studies. , 1996, Circulation.

[52]  J. L. Ubago,et al.  Analysis of the amount of tricuspid valve anular dilatation required to produce functional tricuspid regurgitation. , 1983, The American journal of cardiology.

[53]  Secondary flow velocity patterns in a pulmonary artery model with varying degrees of valvular pulmonic stenosis: pulsatile in vitro studies. , 1990, Journal of biomechanical engineering.

[54]  J. Marshall,et al.  Three-dimensional echocardiographic reconstruction of the mitral valve, with implications for the diagnosis of mitral valve prolapse. , 1989, Circulation.

[55]  Reconsideration of echocardiographic standards for mitral valve prolapse: lack of association between leaflet displacement isolated to the apical four chamber view and independent echocardiographic evidence of abnormality. , 1988, Journal of the American College of Cardiology.

[56]  R C Gorman,et al.  Dynamic three-dimensional imaging of the mitral valve and left ventricle by rapid sonomicrometry array localization. , 1996, The Journal of thoracic and cardiovascular surgery.

[57]  P. Salisbury,et al.  CHORDA TENDINEA TENSION. , 1963, The American journal of physiology.

[58]  Brian John Bellhouse,et al.  Velocity and pressure distributions in the aortic valve , 1969, Journal of Fluid Mechanics.

[59]  J L Heckman,et al.  High speed cine-radiographic study of aortic valve leaflet motion. , 1993, The Journal of heart valve disease.

[60]  A. Weyman,et al.  Papillary muscle traction in mitral valve prolapse: quantitation by two-dimensional echocardiography. , 1992, Journal of the American College of Cardiology.

[61]  G. Waites,et al.  A blood‐testis barrier restricting passage from blood into rete testis fluid but not into lymph , 1969, The Journal of physiology.

[62]  I Vesely,et al.  Natural preload of aortic valve leaflet components during glutaraldehyde fixation: effects on tissue mechanics. , 1993, Journal of biomechanics.

[63]  R A Levine,et al.  The relationship of mitral annular shape to the diagnosis of mitral valve prolapse. , 1987, Circulation.

[64]  W. C. Randall,et al.  Structural basis for cardiac function. , 1970, The American journal of physiology.

[65]  I Vesely,et al.  Biaxial strain analysis of the porcine aortic valve. , 1995, The Annals of thoracic surgery.

[66]  W. M. Swanson,et al.  Dimensions and Geometric Relationships of the Human Aortic Value as a Function of Pressure , 1974, Circulation research.

[67]  A P Yoganathan,et al.  Left ventricular blood flow patterns in normal subjects: a quantitative analysis by three-dimensional magnetic resonance velocity mapping. , 1995, Journal of the American College of Cardiology.

[68]  D. Ghista,et al.  Structural mechanics of the mitral valve: stresses sustained by the valve; non-traumatic determination of the stiffness of the in vivo valve. , 1972, Journal of biomechanics.

[69]  K. Kuwaki,et al.  As originally published in 1989: De Vega's annuloplasty for acquired tricuspid disease: early and late results in 110 patients. Updated in 1996. , 1996, The Annals of thoracic surgery.

[70]  R. Gibbons,et al.  ACC/AHA Guidelines for the Management of Patients With Valvular Heart Disease. Executive Summary. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients With Valvular Heart Disease). , 1998, The Journal of heart valve disease.

[71]  B J Bellhouse,et al.  Instantaneous velocity measurement in major blood vessels: its value in the study of normal and abnormal circulation. , 1969, British heart journal.

[72]  B J Bellhouse,et al.  Fluid mechanics of a model mitral valve and left ventricle. , 1972, Cardiovascular research.

[73]  H. Feigenbaum,et al.  Role of atrium in closure of mitral valve in man. , 1969, The American journal of physiology.

[74]  W. S. Ring,et al.  Finite element analysis of the mitral valve. , 1993, The Journal of heart valve disease.

[75]  P. I. Gerasimov.  Providing the best equipment for soviet health care , 1977 .

[76]  A. Yoganathan,et al.  Axial flow velocity patterns in a normal human pulmonary artery model: pulsatile in vitro studies. , 1990, Journal of biomechanics.

[77]  E. Schwammenthal,et al.  Determinants of functional tricuspid regurgitation in incomplete tricuspid valve closure: Doppler color flow study of 109 patients. , 1994, Journal of the American College of Cardiology.

[78]  E D Wigle,et al.  Morphology of the Human Mitral Valve: II. The Valve Leaflets , 1970, Circulation.

[79]  Peter G. Walker,et al.  Three-dimensional reconstruction of the flow in a human left heart by using magnetic resonance phase velocity encoding , 2007, Annals of Biomedical Engineering.

[80]  C. Tei,et al.  Size and Motion of the Mitral Valve Annulus in Man: I. A Two‐dimensional Echocardiographic Method and Findings in Normal Subjects , 1981, Circulation.

[81]  M. Alam,et al.  Atrioventricular plane displacement and left ventricular function. , 1992, Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography.

[82]  M. Bourgeois,et al.  Size and motion of the mitral valve annulus in anesthetized intact dogs. , 1971, Journal of applied physiology.

[83]  I. Vesely,et al.  Morphology of porcine aortic valve cusp elastin. , 1996, The Journal of heart valve disease.

[84]  I Vesely,et al.  The role of elastin in aortic valve mechanics. , 1997, Journal of biomechanics.

[85]  T. Abe,et al.  De Vega's annuloplasty for acquired tricuspid disease: early and late results in 110 patients. , 1989, The Annals of thoracic surgery.

[86]  E H Wood,et al.  Effect of Ventricular Extrasystoles on Closure of Mitral Valve , 1969, Circulation.

[87]  E. M. Pedersen,et al.  Two-dimensional mitral flow velocity profiles in pig models using epicardial Doppler echocardiography. , 1994, Journal of the American College of Cardiology.

[88]  C. Tei,et al.  The Tricuspid Valve Annulus: Study of Size and Motion in Normal Subjects and in Patients with Tricuspid Regurgitation , 1982, Circulation.

[89]  A. Becker,et al.  Minor congenital variations of cusp size in tricuspid aortic valves. Possible link with isolated aortic stenosis. , 1977, British heart journal.

[90]  W. Meadows,et al.  Premature Mitral Valve Closure: A Hemodynamic Explanation for Absence of the First Sound in Aortic Insufficiency , 1963, Circulation.