Assessment of transmural distribution of myocardial perfusion with contrast echocardiography.

BACKGROUND We hypothesized that by using our newly defined method of destroying microbubbles and measuring their rate of tissue replenishment, we could assess the transmural distribution of myocardial perfusion. METHODS AND RESULTS We studied 12 dogs before and after creation of left anterior descending coronary artery stenoses both at rest and during hyperemia (n=62 stages). Microbubbles were administered as a constant infusion, and myocardial contrast echocardiography (MCE) was performed with the use of different pulsing intervals. The video intensity versus pulsing interval plots derived from each myocardial pixel were fitted to an exponential function: y=A(1-ebetat), where A reflects microvascular cross-sectional area (or myocardial blood volume), and beta reflects mean myocardial microbubble velocity. The product A . beta represents myocardial blood flow (MBF). Average values for these parameters were derived from the endocardial and epicardial regions of interest placed over the left anterior descending coronary artery bed. Radiolabeled microsphere-derived MBF was also measured from the same regions. There was poor correlation between radiolabeled microsphere-derived MBF and A-endocardial/epicardial ratios (EER) (r=0.46). The correlation with beta-EER was better (r=0. 69, P<0.01). The best correlation with radiolabeled microsphere-derived MBF-EER was noted with A . beta-EER (r=0.88, P<0. 01). CONCLUSIONS The transmural distribution of myocardial perfusion can be accurately assessed with MCE with the use of our newly described method of tissue replenishment of microbubbles after their ultrasound-induced destruction. In the model studied, an uncoupling of the transmural distribution of MBF and myocardial blood volume was observed during reversal of the MBF-EER.

[1]  S. Kaul,et al.  Relation between air-filled albumin microbubble and red blood cell rheology in the human myocardium. Influence of echocardiographic systems and chest wall attenuation. , 1996, Circulation.

[2]  H. Matsuda,et al.  Evaluation of regional myocardial perfusion in areas of old myocardial infarction after revascularization by means of intraoperative myocardial contrast echocardiography. , 1994, The Journal of thoracic and cardiovascular surgery.

[3]  G S Kassab,et al.  Morphometry of pig coronary venous system. , 1994, The American journal of physiology.

[4]  A. Weyman.  Principles and Practice of Echocardiography , 1994 .

[5]  P. O’Neill,et al.  Assessment of regional myocardial perfusion by contrast echocardiography. II. Detection of changes in transmural and subendocardial perfusion during dipyridamole-induced hyperemia in a model of critical coronary stenosis. , 1989, Journal of the American College of Cardiology.

[6]  J. Y. Yang,et al.  Pharmacological stress thallium scintigraphy with 2-cyclohexylmethylidenehydrazinoadenosine (WRC-0470). A novel, short-acting adenosine A2A receptor agonist. , 1996, Circulation.

[7]  Melvin L. Marcus,et al.  Cardiac Imaging: A Companion to Braunwald's Heart Disease , 1991 .

[8]  Robert S. Schwartz,et al.  Cardiac Imaging: A Companion to Braunwald's Heart Disease , 1992 .

[9]  G. E. Newman,et al.  Significance of subendocardial S-T segment elevation caused by coronary stenosis in the dog. Epicardial S-T segment depression, local ischemia and subsequent necrosis. , 1977, The American journal of cardiology.

[10]  A R Jayaweera,et al.  Quantification of myocardial blood flow with ultrasound-induced destruction of microbubbles administered as a constant venous infusion. , 1998, Circulation.

[11]  S S Segal,et al.  The behavior of sonicated albumin microbubbles within the microcirculation: a basis for their use during myocardial contrast echocardiography. , 1989, Circulation research.

[12]  S. Kaul,et al.  In vivo myocardial kinetics of air-filled albumin microbubbles during myocardial contrast echocardiography. Comparison with radiolabeled red blood cells. , 1994, Circulation research.

[13]  S. Kaul,et al.  Myocardial Contrast Echocardiography , 2004, Circulation.

[14]  G. J. Crystal,et al.  Transmural Variation in Autoregulation of Coronary Blood Flow in Hyperperfused Canine Myocardium , 1980, Circulation research.

[15]  A R Jayaweera,et al.  Coronary and myocardial blood volumes: noninvasive tools to assess the coronary microcirculation? , 1997, Circulation.

[16]  J I Hoffman,et al.  Blood flow measurements with radionuclide-labeled particles. , 1977, Progress in cardiovascular diseases.

[17]  S. Mellander,et al.  Autoregulation of capillary hydrostatic pressure in skeletal muscle during regional arterial hypo- and hypertension. , 1974, Acta physiologica Scandinavica.

[18]  Sanjiv Kaul,et al.  Quantification of Myocardial Perfusion With Myocardial Contrast Echocardiography During Left Atrial Injection of Contrast: Implications for Venous Injection , 1994, Circulation.

[19]  A R Jayaweera,et al.  Myocardial contrast echocardiography and the transmural distribution of flow: a critical appraisal during myocardial ischemia not associated with infarction. , 1992, Journal of the American College of Cardiology.

[20]  J. Shelburne,et al.  Principles and instrumentation , 1999 .

[21]  S. Kaul,et al.  Quantification of Images Obtained During Myocardial Contrast Echocardiography , 1994, Echocardiography.

[22]  S. Kaul,et al.  Technical factors that influence the determination of microbubble transit rate during contrast echocardiography. , 1995, Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography.

[23]  F W Kremkau,et al.  Physical principles of ultrasound. , 1975, Seminars in roentgenology.

[24]  A J Buda,et al.  Direct measurement of inner and outer wall thickening dynamics with epicardial echocardiography. , 1986, Circulation.

[25]  S. Kaul,et al.  Changes in myocardial blood volume with graded coronary stenosis. , 1997, The American journal of physiology.

[26]  J A Koziol,et al.  Regional myocardial perfusion and wall thickening during ischemia in conscious dogs. , 1984, The American journal of physiology.

[27]  A R Jayaweera,et al.  Basis for detection of stenosis using venous administration of microbubbles during myocardial contrast echocardiography: bolus or continuous infusion? , 1998, Journal of the American College of Cardiology.

[28]  A R Jayaweera,et al.  Method for the quantitation of myocardial perfusion during myocardial contrast two-dimensional echocardiography. , 1990, Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography.

[29]  F. Hanley,et al.  Transmural coronary flow reserve patterns in dogs. , 1986, The American journal of physiology.

[30]  S. Kaul,et al.  Assessment of Risk Area During Coronary Occlusion and Infarct Size After Reperfusion With Myocardial Contrast Echocardiography Using Left and Right Atrial Injections of Contrast , 1993, Circulation.

[31]  R. F. Shaw,et al.  Control of Coronary Blood Flow by an Autoregulatory Mechanism , 1964, Circulation research.

[32]  M. Trivella,et al.  Myocardial washout of sonicated iopamidol does not reflect the transmural distribution of coronary blood flow. , 1993, European heart journal.