John V Tyberg

Summary

Affiliation: University of Calgary
Country: Canada

Publications

  1. doi request reprint The case for the reservoir-wave approach
    John V Tyberg
    Departments of Cardiac Sciences and Physiology Pharmacology and Libin Cardiovascular Institute of Alberta, University of Calgary, Canada Electronic address
    Int J Cardiol 172:299-306. 2014
  2. ncbi request reprint How changes in venous capacitance modulate cardiac output
    John V Tyberg
    Department of Medicine, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada
    Pflugers Arch 445:10-7. 2002
  3. doi request reprint The relationship between left and right pericardial pressures in humans: an intraoperative study
    Douglas R Hamilton
    Department of Family and Community Medicine, Baylor College of Medicine, Texas Medical Center, Houston, Texas, USA
    Can J Cardiol 27:346-50. 2011
  4. ncbi request reprint Effects of positive intrathoracic pressure on pulmonary and systemic hemodynamics
    J V Tyberg
    Department of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Canada
    Respir Physiol 119:171-9. 2000
  5. doi request reprint Wave intensity analysis and the development of the reservoir-wave approach
    John V Tyberg
    Department of Cardiac Sciences, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
    Med Biol Eng Comput 47:221-32. 2009
  6. doi request reprint Effects of vasoconstriction and vasodilatation on LV and segmental circulatory energetics
    Jiun Jr Wang
    Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, AL, Canada T2N 4N1
    Am J Physiol Heart Circ Physiol 294:H1216-25. 2008
  7. ncbi request reprint Wave intensity analysis of left ventricular filling: application of windkessel theory
    Jacqueline A Flewitt
    Libin Cardiovascular Institute of Alberta and Department of Cardiac Sciences, University of Calgary, Alberta, Canada
    Am J Physiol Heart Circ Physiol 292:H2817-23. 2007
  8. ncbi request reprint Ventricular interaction during mechanical ventilation in closed-chest anesthetized dogs
    Jamie R Mitchell
    Department of Physiology and Biophysics, University of Calgary, Alberta
    Can J Cardiol 21:73-81. 2005
  9. ncbi request reprint RV filling modulates LV function by direct ventricular interaction during mechanical ventilation
    Jamie R Mitchell
    Department of Cardiac Sciences, The Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
    Am J Physiol Heart Circ Physiol 289:H549-57. 2005
  10. ncbi request reprint A 2D FE model of the heart demonstrates the role of the pericardium in ventricular deformation
    Carol A Gibbons Kroeker
    Dept of Cardiac Sciences, Faculty of Medicine, Univ of Calgary, Health Sciences Centre, 3330 Hospital Dr NW, Calgary, AB, Canada
    Am J Physiol Heart Circ Physiol 291:H2229-36. 2006

Collaborators

Detail Information

Publications52

  1. doi request reprint The case for the reservoir-wave approach
    John V Tyberg
    Departments of Cardiac Sciences and Physiology Pharmacology and Libin Cardiovascular Institute of Alberta, University of Calgary, Canada Electronic address
    Int J Cardiol 172:299-306. 2014
    ..Clinical studies employing the Reservoir-Wave Approach should be undertaken to verify experimental observations and, perhaps, to gain new diagnostic and therapeutic insights. ..
  2. ncbi request reprint How changes in venous capacitance modulate cardiac output
    John V Tyberg
    Department of Medicine, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada
    Pflugers Arch 445:10-7. 2002
    ..A conceptual model is presented, followed by a discussion of experimental results...
  3. doi request reprint The relationship between left and right pericardial pressures in humans: an intraoperative study
    Douglas R Hamilton
    Department of Family and Community Medicine, Baylor College of Medicine, Texas Medical Center, Houston, Texas, USA
    Can J Cardiol 27:346-50. 2011
    ....
  4. ncbi request reprint Effects of positive intrathoracic pressure on pulmonary and systemic hemodynamics
    J V Tyberg
    Department of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Canada
    Respir Physiol 119:171-9. 2000
    ..Although these interventions decrease RV transmural pressure, they may increase LV transmural pressure, end-diastolic volume, and thus stroke work by the Frank-Starling mechanism...
  5. doi request reprint Wave intensity analysis and the development of the reservoir-wave approach
    John V Tyberg
    Department of Cardiac Sciences, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada
    Med Biol Eng Comput 47:221-32. 2009
    ..This component is the pressure generated by the filling and emptying of the reservoir, Otto Frank's Windkessel...
  6. doi request reprint Effects of vasoconstriction and vasodilatation on LV and segmental circulatory energetics
    Jiun Jr Wang
    Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, AL, Canada T2N 4N1
    Am J Physiol Heart Circ Physiol 294:H1216-25. 2008
    ..Approximately 60% of LV stroke work is stored as the potential energy during systole under control, and the ratio decreases to approximately 45% with NP and approximately 80% with MTX...
  7. ncbi request reprint Wave intensity analysis of left ventricular filling: application of windkessel theory
    Jacqueline A Flewitt
    Libin Cardiovascular Institute of Alberta and Department of Cardiac Sciences, University of Calgary, Alberta, Canada
    Am J Physiol Heart Circ Physiol 292:H2817-23. 2007
    ..6 times greater than we previously calculated. Volume-related changes in pressure (i.e., the windkessel or reservoir effect) must be considered first when wave motion is analyzed...
  8. ncbi request reprint Ventricular interaction during mechanical ventilation in closed-chest anesthetized dogs
    Jamie R Mitchell
    Department of Physiology and Biophysics, University of Calgary, Alberta
    Can J Cardiol 21:73-81. 2005
    ..The reverse occurred during expiration. Positive end-expiratory pressure constrained left ventricular filling and decreased left ventricular end-diastolic volume further by a leftward septal shift...
  9. ncbi request reprint RV filling modulates LV function by direct ventricular interaction during mechanical ventilation
    Jamie R Mitchell
    Department of Cardiac Sciences, The Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
    Am J Physiol Heart Circ Physiol 289:H549-57. 2005
    ..We conclude that phasic changes in systemic venous return during mechanical ventilation modulate left ventricular function by direct ventricular interaction...
  10. ncbi request reprint A 2D FE model of the heart demonstrates the role of the pericardium in ventricular deformation
    Carol A Gibbons Kroeker
    Dept of Cardiac Sciences, Faculty of Medicine, Univ of Calgary, Health Sciences Centre, 3330 Hospital Dr NW, Calgary, AB, Canada
    Am J Physiol Heart Circ Physiol 291:H2229-36. 2006
    ..Furthermore, the deformation of the heart is dependent on whether the pericardium is open or closed...
  11. doi request reprint Wave propagation and reflection in the canine aorta: analysis using a reservoir-wave approach
    Jiun Jr Wang
    Department of Cardiac Sciences, University of Calgary, Calgary, Alberta, Canada
    Can J Cardiol 27:389.e1-10. 2011
    ..Accordingly, in this research we calculated reservoir pressure and subtracted it from measured pressure to identify the change in pressure due to forward- or backward-travelling waves...
  12. ncbi request reprint Systemic venous circulation. Waves propagating on a windkessel: relation of arterial and venous windkessels to systemic vascular resistance
    Jiun Jr Wang
    Dept of Cardiac Sciences, Univ of Calgary, Health Sciences Center, 3330 Hospital Dr NW, Calgary, Alberta, Canada T2N 4N1
    Am J Physiol Heart Circ Physiol 290:H154-62. 2006
    ..Thus the venous windkessel model not only successfully accounts for variations in the venous pressure and flow waveforms but also, in combination with the arterial windkessel, provides a coherent view of the systemic circulation...
  13. ncbi request reprint Measuring transient systemic conductance and capacitance responses using a modified Brooksby-Donald technique in anesthetized, autonomically intact rabbits
    Christopher I Wright
    Department of Medicine, University of Calgary, Alberta
    Can J Cardiol 20:1127-34. 2004
    ..The Brooksby-Donald approach uses two flow probes to measure the inflow and outflow from an organ or vascular bed; the difference in flow can be time-integrated to assess changes in venous capacitance...
  14. ncbi request reprint Time-domain representation of ventricular-arterial coupling as a windkessel and wave system
    Jiun Jr Wang
    Department of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
    Am J Physiol Heart Circ Physiol 284:H1358-68. 2003
    ..We suggest that P(Ao) is the instantaneous summation of a time-varying reservoir pressure (i.e., P(Wk)) and the effects of (primarily) forward-traveling waves in this animal model...
  15. ncbi request reprint Assessment of right ventricular diastolic suction in dogs with the use of wave intensity analysis
    Yichun Sun
    Department of Cardiac Sciences, University of Calgary, Calgary, Alberta, Canada T2N 4N1
    Am J Physiol Heart Circ Physiol 291:H3114-21. 2006
    ..Despite the thin wall and nonspherical shape of the RV, DS appears to be an important mechanism...
  16. pmc Oxygenation-sensitive CMR for assessing vasodilator-induced changes of myocardial oxygenation
    Matthias Vöhringer
    Stephenson Cardiovascular MR Centre at the Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, University of Calgary, Calgary, AB, Canada
    J Cardiovasc Magn Reson 12:20. 2010
    ....
  17. doi request reprint Volume loading reduces pulmonary vascular resistance in ventilated animals with acute lung injury: evaluation of RV afterload
    Jamie R Mitchell
    Department of Cardiac Sciences, University of Calgary, Alberta, Canada
    Am J Physiol Regul Integr Comp Physiol 300:R763-70. 2011
    ....
  18. ncbi request reprint Pericardium modulates left and right ventricular stroke volumes to compensate for sudden changes in atrial volume
    Carol A Gibbons Kroeker
    University of Calgary, Alberta, Canada T2N 4N1
    Am J Physiol Heart Circ Physiol 284:H2247-54. 2003
    ..Pericardial constraint appears essential for immediate biventricular compensatory responses to acute atrial volume changes...
  19. doi request reprint Mechanism of loss of consciousness during vascular neck restraint
    Jamie R Mitchell
    Department of Cardiac Sciences, University of Calgary, Calgary, Alberta, Canada
    J Appl Physiol (1985) 112:396-402. 2012
    ..In addition, with no significant change in HR, ventricular contractility, or MAP, the carotid sinus baroreceptor reflex appears to contribute little to the response to VNR...
  20. doi request reprint "Wave" as defined by wave intensity analysis
    Jiun Jr Wang
    Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Canada
    Med Biol Eng Comput 47:189-95. 2009
    ..Results demonstrate that forward- and backward-travelling peaks of intensity usefully define wave interactions...
  21. ncbi request reprint Opening the pericardium during pulmonary artery constriction improves cardiac function
    Israel Belenkie
    Department of Medicine, University of Calgary, Alberta, Canada
    J Appl Physiol (1985) 96:917-22. 2004
    ..Pericardiotomy can improve LV function in the absence of other sources of external constraint to LV filling...
  22. ncbi request reprint Wave intensity analysis of left atrial mechanics and energetics in anesthetized dogs
    Tracy N Hobson
    Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, Health Sciences Centre, Univ of Calgary, Calgary, Alberta, Canada
    Am J Physiol Heart Circ Physiol 292:H1533-40. 2007
    ..Thus wave reflection due to increased LV stiffness accounts for the decrease in the A wave and the increase in the Ar wave measured by Doppler...
  23. ncbi request reprint Compression induced by RV pressure overload decreases regional coronary blood flow in anesthetized dogs
    Carol A Gibbons Kroeker
    Cardiovascular Research Group, Faculty of Medicine, University of Calgary Health Sciences Centre, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
    Am J Physiol Heart Circ Physiol 290:H2432-8. 2006
    ..This may help explain why some patients with pulmonary hypertension and no critical coronary disease have chest discomfort indistinguishable from angina pectoris...
  24. ncbi request reprint Relationship between right ventricular wave speed and elastance in dogs
    Yichun Sun
    Department of Cardiac Sciences and Physiology, The Libin Cardiovascular Institute of Alberta, University of Calgary Health Sciences Centre, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
    Can J Physiol Pharmacol 84:943-51. 2006
    ..31. Given knowledge of c, forward- and backward-going waves can be identified and their energy quantitated. In the canine RV, c is approximately proportional to 1/3 the power of elastance: log c = 0.31.log E - 2.05...
  25. ncbi request reprint Atrioventricular nonuniformity of pericardial constraint
    Douglas R Hamilton
    Department of Family and Community Medicine, Texas Medical Center, Baylor College of Medicine, Houston, TX 77098, USA
    Am J Physiol Heart Circ Physiol 287:H1700-4. 2004
    ..Systolic nonuniformity of pericardial constraint may augment the atrioventricular valve-opening pressure gradient in early diastole and, so, affect ventricular filling...
  26. ncbi request reprint Effects of left ventricular contractility and coronary vascular resistance on coronary dynamics
    Yi Hui Sun
    Department of Medicine, University of Calgary Health Sciences Centre, Calgary, Alberta, Canada T2N 4N1
    Am J Physiol Heart Circ Physiol 286:H1590-5. 2004
    ..I(W-) was proportional to the CSFI. We conclude that contractility and coronary resistance change CSFI by modulating the backward-going compression wave...
  27. doi request reprint Classical electrical and hydraulic Windkessel models validate physiological calculations of Windkessel (reservoir) pressure
    Sarup S Sridharan
    Department of Cardiac Sciences, University of Calgary, AB, Canada
    Can J Physiol Pharmacol 90:579-85. 2012
    ..The results of this study validate P(reservoir) and, thus, the reservoir-wave approach...
  28. ncbi request reprint Characterization of the upper limb arterial properties during reactive hyperemia
    Gary Dobson
    Department of Anesthesiology, University of Calgary, Calgary, Canada
    Cardiovasc Eng 7:127-34. 2007
    ..The AIx of RA is determined to an equal extent by the input and local factors. Interpretation of the AIx of the RA and the reconstructed central aortic waveform should be made in the context of this relationship...
  29. ncbi request reprint Effects of acute volume loading and hemorrhage on intestinal vascular capacitance: a mechanism whereby capacitance modulates cardiac output
    Nairne W Scott-Douglas
    Foothills Medical Centre, Foothills Hospital, Calgary, Alberta, Canada
    Can J Cardiol 18:515-22. 2002
    ..Changes in intestinal vascular capacitance during acute volume loading and hemorrhage have not been described...
  30. ncbi request reprint Compression of interventricular septum during right ventricular pressure loading
    G S Nelson
    Departments of Medicine, Physiology and Biophysics and Civil Engineering, University of Calgary, Calgary, Alberta T2N 4N1, Canada
    Am J Physiol Heart Circ Physiol 280:H2639-48. 2001
    ..Such stresses might impede septal blood flow and provoke the unexplained ischemia observed in some conditions characterized by abnormal septal motion...
  31. ncbi request reprint Evidence for left ventricular constraint during open heart surgery
    Israel Belenkie
    Department of Medicine, University of Calgary, Canada
    Can J Cardiol 18:951-9. 2002
    ..The degree to which the lungs and other mediastinal structures constrain the heart during cardiac surgery is uncertain...
  32. ncbi request reprint Direct and series transmission of left atrial pressure perturbations to the pulmonary artery: a study using wave-intensity analysis
    Ellen H Hollander
    Department of Medicine, 3330 Hospital Dr NW, Calgary, Alberta, Canada T2N 4N1
    Am J Physiol Heart Circ Physiol 286:H267-75. 2004
    ..Pressure waves from the LA arrive in the PA by two distinct routes: rapidly and directly through the heart and delayed and in-series through the pulmonary vasculature...
  33. ncbi request reprint Ventricular interaction: from bench to bedside
    I Belenkie
    Department of Medicine, University of Calgary, Alberta, Canada
    Ann Med 33:236-41. 2001
    ..The decreased stroke work is a result of reduced LV preload, not decreased contractility as would be suggested if filling pressure is used to reflect preload...
  34. ncbi request reprint Orthostatic hypotension and the role of changes in venous capacitance
    J V Tyberg
    Department of Medicine, University of Calgary, Alberta, Canada
    Med Sci Sports Exerc 28:S29-31. 1996
    ..To prevent this sequence of events, leg cuffs might be inflated before the end of the space flight to allow homeostatic mechanisms to increase blood volume to normal levels...
  35. ncbi request reprint Vascular and cardiac effects of amlodipine in acute heart failure in dogs
    D L Isaac
    Department of Medicine, University of Calgary, Alberta
    Can J Cardiol 14:1375-82. 1998
    ..Amlodipine improves exercise capacity in patients with chronic congestive heart failure (HF), but the mechanisms of this effect are unknown...
  36. ncbi request reprint Ventricular interaction and venous capacitance modulate left ventricular preload
    J V Tyberg
    Department of Medicine, University of Calgary, Alberta
    Can J Cardiol 12:1058-64. 1996
    ..To optimize the care of patients with heart disease, it is important to understand both these mechanisms...
  37. ncbi request reprint A novel technique for measurement of pericardial pressure
    G deVries
    Department of Medicine and Department of Physiology and Biophysics, University of Calgary, Calgary, Alberta, Canada T2N 4N1
    Am J Physiol Heart Circ Physiol 280:H2815-22. 2001
    ..Furthermore, we suggest that earlier measurements of pericardial "liquid pressure" were low, due to an artifact of measurement...
  38. pmc Genesis of the characteristic pulmonary venous pressure waveform as described by the reservoir-wave model
    J Christopher Bouwmeester
    Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
    J Physiol 592:3801-12. 2014
    ..In sharp contrast, conventional analysis posits forward and backward waves such that much of the energy of the forward wave is opposed by the backward wave...
  39. doi request reprint Altered mesenteric venous capacitance and volume pooling in cirrhotic rats are mediated by nitric oxide
    Yang Li
    Liver Unit, Gastrointestinal Research Group, Calgary, Alberta, Canada
    Am J Physiol Gastrointest Liver Physiol 295:G252-9. 2008
    ..The first two abnormalities were caused by neuronal NOS-derived nitric oxide...
  40. doi request reprint A pharmacologic activator of endothelial KCa channels increases systemic conductance and reduces arterial pressure in an anesthetized pig model
    Ramesh C Mishra
    Dept of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada The Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
    Vascul Pharmacol 79:24-31. 2016
    ..Primary reductions in mPAO by SKA-31 largely account for associated decreases in SW, implying that SKA-31 does not directly impair cardiac contractility. ..
  41. doi request reprint Edema as a very early marker for acute myocardial ischemia: a cardiovascular magnetic resonance study
    Hassan Abdel-Aty
    Stephenson CMR Centre at the Libin Cardiovascular Institute of Alberta, Calgary, Alberta, Canada
    J Am Coll Cardiol 53:1194-201. 2009
    ..This study was designed to determine whether imaging myocardial edema would identify acute myocardial ischemia before irreversible injury takes place...
  42. ncbi request reprint Comparative effects of nitroglycerin on intestinal vascular capacitance and conductance
    Eiichi Chihara
    Department of Medicine, University of Calgary and Foothills Hospital, Calgary, Alberta
    Can J Cardiol 18:165-74. 2002
    ..Nitroglycerin (NTG) dilates capacitance veins and resistance arterioles, but its relative effects on veins and arterioles are not known...
  43. ncbi request reprint Left ventricular wave speed
    J J Wang
    Department of Medicine and Physiology and Biophysics, University of Calgary Health Science Centre, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
    J Appl Physiol 91:2531-6. 2001
    ..The slope of the log c (where c is wave speed) vs. log gamma was 0.546, which is in agreement with theory (0.5). When gamma < or = 0, LVWS was approximately 1.5 m/s...
  44. ncbi request reprint The isolated working mouse heart: methodological considerations
    T S Larsen
    Department of Physiology and Biophysics, University of Calgary, Faculty of Medicine, Calgary, Alberta, Canada T2N 4N1
    Pflugers Arch 437:979-85. 1999
    ..The heights of the afterload column and the preload reservoir are unreliable and potentially misleading indicators of LV afterload and preload...
  45. doi request reprint Systemic vascular effects of acute electrical baroreflex stimulation
    Steven Burgoyne
    Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada
    Am J Physiol Heart Circ Physiol 307:H236-41. 2014
    ..In conclusion, BAT increases arterial conductance, decreases PAo, and increases venous capacitance even in the presence of powerful vasoactive drugs. Increasing venous capacitance may be an important effect of BAT in hypertension. ..
  46. ncbi request reprint Negative wave reflections in pulmonary arteries
    E H Hollander
    Departments of Medicine and Physiology and Biophysics, Cardiovascular Research Group, University of Calgary, Calgary, Alberta, Canada, T2N 4N1
    Am J Physiol Heart Circ Physiol 281:H895-902. 2001
    ..The normal pulmonary arterial circulation in the open-chest dog is characterized by negative wave reflection tending to facilitate right ventricular ejection; this reflection increases with increasing blood volume and PEEP...
  47. ncbi request reprint Endografting of the descending thoracic aorta increases ascending aortic input impedance and attenuates pressure transmission in dogs
    G Dobson
    Department of Anesthesia and Surgery, University of Calgary, Calgary, Alta, Canada
    Eur J Vasc Endovasc Surg 32:129-35. 2006
    ..The acute effects of such interventions on ventricular afterload and on pressure wave transmission characteristics are not well known...
  48. ncbi request reprint Static and dynamic operating characteristics of a pericardial balloon
    D R Hamilton
    Department of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1
    J Appl Physiol 90:1481-8. 2001
    ..When better dynamic response is required, we introduce a micromanometer-tipped catheter to obtain a unity-gain frequency response that is flat to 200 Hz...
  49. ncbi request reprint Comments on Point:Counterpoint series "Active venoconstriction is/is not important in maintaining or raising end-diastolic volume and stoke volume during exercise and orthostasis."
    Wayne Mitzner
    Johns Hopkins University, USA
    J Appl Physiol 101:1267-8. 2006
  50. ncbi request reprint Assessment of left ventricular diastolic suction in dogs using wave-intensity analysis
    Zhibin Wang
    Qingdao University Medical College Hospital, Qingdao, China
    Am J Physiol Heart Circ Physiol 288:H1641-51. 2005
    ..e., tau) and V(LVES). WIA provides a new approach for assessing DS and reconciles those two previously proposed mechanisms. The E wave depends on DS in addition to LA decompression...
  51. ncbi request reprint Does fitness level modulate the cardiovascular hemodynamic response to exercise?
    Michael K Stickland
    Faculty of Physiucal Education and Recreation, University of Alberta, Edmonton, Canada
    J Appl Physiol (1985) 100:1895-901. 2006
    ....
  52. ncbi request reprint Effects of exogenous and endogenous natriuretic peptides on forearm vascular function in chronic heart failure
    Matthias Schmitt
    Wales Heart Research Institute, Cardiff, UK
    Arterioscler Thromb Vasc Biol 24:911-7. 2004
    ....