An Update on the Use of Intracoronary Doppler and Pressure Measurements

An Update on the Use of Intracoronary Doppler and Pressure Measurements

European Cardiology 2005
Published: May 2005
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Introduction
The development of selective coronary angiography in the 1960s by Sones 1 offered a dramatic improvement in the management of ischaemic heart disease. However, decisions could only be made on ‘shadowgrams’ of coronary stenoses. Early invasive assessment of stenosis severity and coronary flow have been developed, based on the Doppler effect, using a piezoelectric crystal mounted at the tip of standard Sones catheters 2 or on intraluminal probes. 3However, partial obstruction of the coronary ostium by these devices limited their clinical use.

When Gruntzig performed his first percutaneous transluminal coronary angioplasty (PTCA) in 1977, the concept of physiological assessment of the results of percutaneous interventions (PCI) was already introduced. 4 The double-lumen dilatation catheters permitted balloon inflation on one side and the recording of the distal coronary pressure on the other side. Trans-stenotic pressure gradients were used to monitor the procedures – a residual trans-stenotic gradient less than 20mmHg was considered optimal. 5 However, with technical developments like the flexible-tipped guidewires introduced in the lumen, previously used to measure pressure, and the introduction of low-profile balloons, pressure recordings were more difficult to perform. Moreover, the relations between the measured pressure gradient, the diameter stenosis and the lesion length were imprecisely known, and were dependent on the presence of the catheter itself in the stenosis. 6 With the development of parameters to assess the functional significance of a stenosis from its geometry, 7 it was considered that the available anatomical information was sufficient. Nowadays, the angiogram is still considered by most physicians to be the ‘gold standard’ for defining coronary anatomy. However, its resolution is limited and numerous confounding factors (vessel tortuosity, overlap of structures, etc.) result in a marked disparity between the apparent severity of a lesion and its physiological effect. 8-10

Principles of Doppler Velocimetry
An observer moving towards a sound source will hear a tone with higher frequency than when stationary and an observer moving away from the source will hear a tone of lower frequency. This change in frequency is called the Doppler effect. This principle is applied in practice by mounting a piezoelectric crystal that emits and receives high-frequency sounds on the tip of an intravascular catheter. The blood flow velocity alters the return frequency, causing the Doppler shift. Electronic circuits performing spectral analysis of the received signal allow continuous determination of the Doppler shift, and of blood flow velocity, based on the following Doppler equation:

Itra Coronary Dopler

V=velocity of blood flow
F0 = transmitting (transducer) frequency
F1 = returning frequency
C = constant: speed of sound in blood
φ = angle of incidence.

References:
  1. W L Proudfit, E K Shirey and F M Sones Jr, “Selective cine coronary arteriography, Correlation with clinical findings in 1,000 patients”, Circulation (1966), 33 (6): pp.901–910.
  2. C Hartley and J Cole, “An ultrasonic pulsed Doppler system for measuring blood flow in small vessels”, J. Appl. Physiol. (1974), 37: p. 626.
  3. R F Wilson, D E Laughlin, P H Ackell, et al., “Transluminal, subselective measurement of coronary artery blood flow velocity and vasodilator reserve in man”, Circulation (1985), 72: p. 82.
  4. A R Grüntzig, A Senning and W E Siegenthaler, “Nonoperative dilatation of coronary artery stenosis”, N. Engl. J. Med. (1979), 301 (2): pp. 61–68.
  5. M T Rothman, D S Baim, J B Simpson and D C Harrison, “Coronary hemodynamics during percutaneous transluminal coronary angioplasty”, Am. J. Cardiol. (1982), 49 (7): pp. 1,615–1,622.
  6. H V Anderson, G S Roubin, P P Leimgruber, W R Cox, J S Douglas, S B King, et al., “Measurement of transtenotic pressure gradient during percutaneous transluminal coronary angioplasty”, Circulation (1986), 73 (3): pp. 1,223–1,230.
  7. K Gould, K Kelley and E Bolson, “Experimental validation of quantitative coronary arteriography for determining pressure-flow characteristics of coronary stenosis”, Circulation (1982), 66 (5): pp. 930–937.
  8. C W White, C B Wright, D B Doty, L F Hiratza, C L Eastham, D G Harrison, et al., “Does visual interpretation of the coronary arteriogram predict the physiologic importance of a coronary stenosis?” N. Engl. J. Med. (1984), 310 (13): pp. 819–824.
  9. D Miller, T Donohue, L Younis, R Bach, F Aguirre, M Wittry, et al., “Correlation of pharmacological 99mTcsestamibi myocardial perfusion imaging with poststenotic coronary flow reserve in patients with angiographycally intermediate coronary artery stenoses”, Circulation (1994), 89 (5): pp. 2,150–2,160.
  10. E J Topol and S E Nissen, “Our preocupation with coronary luminology. The dissociation between clinical and angiographic findings in ischemic heart disease”, Circulation (1995), 92: pp. 2,333–2,342.
  11. D Kilpatrick and S Webber, “Intravascular blood velocity in simulated coronary artery stenoses”, Cathet. Cardiovasc. Diagn. (1986), 12: p. 317.
  12. L Hatle and B Angelsen, “Physics of blood flow”, In: L Hatle, B Angelsen, (eds), Doppler Ultrasound in Cardiology, Philadelphia: Lea & Febiger; (1982), p. 8–31.
  13. G Porenta, H Schima, A Pentaris, S Tsangaris, D Moertl, P Probst, et al., “Assessment of coronary stenoses by Doppler wires: a validation study using in vitro modeling and computer simulations”, Ultrasound Med. Biol. (1999), 25 (5): pp. 793–801.
  14. J A E Spaan, “Structure and function of the coronary arterial tree”, In: J A E Spaan, (ed), Coronary blood flow: mechanics, distribution and control, Boston: Kluwer Academic Publishers; (1991), p. 37–67.
  15. K L Gould, K Lipscomb, and G W Hamilton, “Physiologic basis for assessing critical coronary stenosis: Instantaneous flow response and regional distribution during coronary hyperemia as measures of coronary flow reserve”, Am. J. Cardiol. (1974), 33: pp. 87–94.
  16. F J Klocke, “Measurements of coronary flow reserve: Defining pathophysiology versus making decisions about patient care”, Circulation (1987), 76 (6): pp. 1,183–1,189.
  17. J I Hoffman and J A Spaan, “Pressure-flow relations in coronary circulation”, Physiol. Rev. (1990), 70 (2): pp. 331–390.
  18. M Sugawara, “Stenosis: Theoretical background”, In: M Sugawara, F Kajiya, A Kitabatake, H Matsuo (eds) Blood Flow in the Heart and Large Vessels, Tokyo-Berlin-New York: Springer-Verlag; (1989), p. 91.
  19. N H J Pijls, B de Bruyne, K Peels, P van der Voort, H J R M Bonnier, J Bartunek, et al., “Measurement of fractional flow reserve to assess the functional severity of coronary-artery stenoses”, N. Engl. J. Med. (1996), 334 (26): pp. 1,703–1,708.
  20. M J Kern, “Coronary physiology revisited : practical insights from the cardiac catheterization laboratory”, Circulation (2000), 101 (11): pp. 1,344–1,351.
  21. M Ferrari, B Schnell, G S Werner and H R Figulla, “Safety of deferring angioplasty in patients with normal coronary flow velocity reserve”, J. Am. Coll. Cardiol. (1999), 33 (1): pp. 82–87.
  22. G J Bech, B De Bruyne, N H Pijls, E D de Muinck, J C Hoorntje, J Escaned, et al., “Fractional flow reserve to determine the appropriateness of angioplasty in moderate coronary stenosis: a randomized trial”, Circulation (2001), 103 (24): pp. 2,928–2,934.
  23. K L Gould, R L Kirkeeide and M Buchi, “Coronary flow reserve as a physiologic measure of stenosis severity”, J. Am. Coll. Cardiol. (1990), 15: pp. 459–477.
  24. D Baumgart, M Haude, G Goerge, J Ge, S Vetter, N Dagres, et al., “Improved assessment of coronary stenosis severity using the relative flow velocity reserve”, Circulation (1998), 98 (1): pp. 40–46.
  25. M J Kern, S Puri, R G Bach, T J Donohue, P Dupouy, E A Caracciolo, et al., “Abnormal coronary flow velocity reserve after coronary artery stenting in patients: role of relative coronary reserve to assess potential mechanisms”, Circulation (1999), 100 (25): pp. 2,491–2,498.
  26. R A van Liebergen, J J Piek, K T Koch, R J Peters, R J de Winter, C E Schotborgh, et al., “Hyperemic coronary flow after optimized intravascular ultrasound-guided balloon angioplasty and stent implantation”, J. Am. Coll. Cardiol. (1999), 34 (7): pp. 1,899–1,906.
  27. E J Topol, S G Ellis, D M Cosgrove, E R Bates, D W Muller,N J Schork, et al., “Analysis of coronary angioplasty practice in the United States with an insurance-claims data base”, Circulation (1993), 87 (5): pp. 1,489–1,497.
  28. M A Leesar, T Abdul-Baki, N I Akkus, A Sharma, T Kannan and R Bolli, “Use of fractional flow reserve versus stress perfusion scintigraphy after unstable angina, Effect on duration of hospitalization, cost, procedural characteristics, and clinical outcome”, J. Am. Coll. Cardiol. (2003), 41 (7): pp. 1,115–1,121.
  29. O P Pitkanen, O T Raitakari, H Niinikoski, P Nuutila, H Iida, L M Voipio-Pulkki, et al., “Coronary flow reserve is impaired in young men with familial hypercholesterolemia”, J. Am. Coll. Cardiol. (1996), 28 (7): pp. 1,705–1,711.
  30. F W Selke, M L Armstrong and D G Harrison, “Endothelium- dependent vascular relaxation is abnormal in the coronary microcirculation of atherosclerotic primates”, Circulation (1990), 81: pp. 1,586–1,593.
  31. R M Palmer, D S Ashton and S Moncada, “Vascular endothelial cells synthesize nitric oxide from L-arginine”, Nature (1988), 333: pp. 664–666.
  32. U Fostermann, A Mugge, U Alheid, et al., “Selective attenuation of endothelium-mediated vasodilation in atherosclerotic human coronary arteries”, Circ. Res. (1988), 62: pp. 185–190.
  33. J A Panza, A A Quyyumi, J E J R Brush, et al., “Abnormal endothelium-dependent vascular relaxation in patients with essential hypertension”, N. Engl. J. Med. (1990), 323: pp. 22–27.
  34. M T Johnstone, S J Gallagher, K M Scales, J A Cusco, B Lee and M A Creager, “Endothelium-dependent vasodilatation is impaired in patients with insulin-dependent diabetes mellitus”, Circulation (1992), 68: I–618.
  35. P L Ludmer, A P Selwyn, T L Shook, et al., “Paradoxical vasoconstriction induced by acetylcholine in atherosclerotic coronary arteries”, N. Engl. J. Med. (1986), 315: p. 1,046.
  36. S D Werns, J A Walton, H H Hsia, et al., “Evidence of endothelial dysfunction in angiographically normal coronary arteries of patients with coronary artery disease”, Circulation (1989), 79: p. 287.
  37. J A Vita, C B Treasure, E G Nabel, et al., “Coronary vasomotor response to acetylcholine relates to risk factors in coronary artery disease”, Circulation (1990), 81: p. 491.
  38. H Yasue, K Matsuyama, K Okumura, et al., “Responses of angiographically normal human coronary arteries to intracoronary injection of acetylcholine by age and segment”, Circulation (1990), 81: pp. 482–490.
  39. Y Horio, H Yasue, M Rokutanda, N Nakamura, H Ogawa, K Takaoka, et al., “Effects of intracoronary injection of acetylcholine on coronary arterial diameter”, Am. J. Cardiol. (1986), 57 (11): pp. 984–989.
  40. M C Corretti, T J Anderson, E J Benjamin, D Celermajer, F Charbonneau, M A Creager, et al., “Guidelines for the ultrasound assessment of endothelial-dependent flow-mediated vasodilation of the brachial artery: a report of the International Brachial Artery Reactivity Task Force”, J. Am. Coll. Cardiol. (2002), 39 (2): pp. 257–265.
  41. T J Anderson, A Uehata, M D Gerhard, I T Meredith, S Knab, D Delagrange, et al., “Close relation of endothelial function in the human coronary and peripheral circulations”, J. Am. Coll. Cardiol. (1995), 26 (5): pp. 1,235–1,241.
  42. T Neunteufl, S Heher, R Katzenschlager, G Wolfl, K Kostner, G Maurer, et al., “Late prognostic value of flowmediated dilation in the brachial artery of patients with chest pain”, Am. J. Cardiol. (2000), 86 (2): pp. 207–210.
  43. J P Halcox, W H Schenke, G Zalos, R Mincemoyer, A Prasad, M A Waclawiw, et al., “Prognostic value of coronary vascular endothelial dysfunction”, Circulation (2002), 106 (6): pp. 653–658.

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