Myocardial Perfusion Abnormalities by Intravenous Administration of the Contrast Agent NC100100 in an Experimental Model of Coronary Artery Thrombosis and Reperfusion (original) (raw)
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Contrast echocardiography for assessment of myocardial perfusion
Herz, 1997
It has been suggested that the myocardial perfusion can be qualitatively and quantitatively assessed by different ultrasound contrast techniques. It has been reported that the intracoronary or intraaortic administration of the ultrasound contrast agents can be used to visualize perfusion defects or to analyze the coronary flow reserve. The perfusion analysis after intracoronary injection of ultrasound contrast agents sectas to be established, but there are a lot of open questions. A topographic (qualitative) perfusion analysis with visualization of perfusion defects and perfusion areas or analysis of collaterals has been demonstrated. A quantitative analysis of myocardial blood flow has been described but the existing studies ate inconsistent. It i; not known which parameters of the contrast wash-out curves should be used for perfusion analysis and ir the Stewart-Hamilton curve analysis can be transfered to all ultrasound contrast agents asa model for quantitative myocardial blood flow assessment. The development of the transpulmonary contrast agents for echocardiographic eval-uation of left ventricular cavity has the impact for myocardial perfusion imaging. The increase of myocardial intensity does not mean that a qualitative or quantitative perfusion analysis can be clinically used. In this field we have to differentiate between the possibilities of qualitative discrimination of perfusion defects and quantitative perfusion (myocardial blood flow) analysis. The different scanning conditions, the poor transthoracic ultrasound window and insufficient enhancemant of the myocardial intensity make it problematic to quantify the myocardial perfusion. At the moment myocardial intensity will be increased after intravenous injection of transpulmonary contrast agents, but the value for perfusion analysis has not been shown. New ultrasound technologies such as second harmonic imaging, power-mode and raw data analysis have to show the clinical importance of these techniques for perfusion analysis in daily clinical routine. The open questions of the perfusion analysis by contrast echocardiography will be discussed in this review article.
American Heart Journal, 1996
The use ofintracoronary or intraaortic root injections of echo-contrast agents, myocardial contrast echocardiography (MCE), has proved useful in delineating individual coronary artery perfusion territories i and myocardial areas at risk 2"3 and in assessing coronary reserve, 4-i° results of percutaneous transluminal coronary angioplasty 6, 11-i2 and coronary artery bypass grafting, i3 presence and degree of coronary collaterals, i4~i5 and more recently the presence of myocardial viability in asynergic myocardium.15-i6 However, investigators have experienced variable degrees of success in obtaining sufficient transpulmonary passage ofechocardiographic contrast agents to achieve reproducible myocardial opacification.i7-25 This unpredictable transpulmonary passage has limited the use of MCE to the catheterization laboratory and has prevented the widespread application of the technique. Preliminary investigations by us and others would suggest that newer echocardiographic contrast agents might be able to achieve myocardial opacification after their intravenous injection. 26-3i On the basis of our preliminary observations 26-27 we hypothesized that FSO69, a new echocardiographic contrast agent that consists of a suspension of perfluoropropane-filled albumin mi-From the aSection
Myocardial Perfusion Imaging Using Contrast Echocardiography
Herz, 2002
Background: Intense work during the last two decades has brought forth the use of myocardial contrast echocardiography to the clinical threshold for the diagnosis and evaluation of coronary artery disease. Clinical Use: A number of ultrasound contrast agents have been developed that act as red blood cell tracers and display myocardial perfusion when imaged by dedicated ultrasound imaging modalities. A considerable amount of experimental and clinical research has shown that myocardial contrast echocardiography can aid in the recognition of acute and chronic myocardial infarction, viable myocardium, and functionally significant coronary stenoses. Comparison of this Myokardperfusions-Imaging mit Kontrastechokardiographie Hintergrund: Die intensive Auseinandersetzung mit der myokardialen Kontrastechokardiographie hat nach zwei Jahrzehnten nunmehr die Grenze zum klinischen Einsatz bei der Diagnostik und Evaluierung der koronaren Herzkrankheit erreicht. Klinische Anwendung: Eine Reihe von Ultraschallkontrastsubstanzen ist inzwischen entwickelt worden, die als Erythrozytentracer fungieren und die in der Lage sind, unter Verwendung entsprechender Ultraschalltechnologien myokardiale Perfusion am Bildschirm darzustellen. Extensive experimentelle und klinische Forschung konnte zeigen, dass die myokardiale Kontrastechokardiographie zur Erfassung von akutem und chronischem Myokardinfarkt, Myokardvitalität und funktionell signifikanten Koronarstenosen dienen kann. Im Ver-gleich mit nuklearmedizinischen Methoden und Koronarangiographie zeigt die Kontrastechokardiographie eine sehr gute diagnostische Genauigkeit bei der Evaluierung von verschiedenen Koronarsyndromen. Die optimale Darstellung myokardialer Perfusion erfordert eine grundsätzliche Kenntnis über die Charakteristik von Mikrobläschen und Abbildungstechniken sowie entsprechende Erfahrung. Perspektive: Die Technologie ist in Weiterentwicklung von der intermittierenden zur Echtzeitdarstellung begriffen, die sowohl die Beurteilung der Perfusion als auch funktioneller Parameter gestattet. Neben der diagnostischen Anwendung am Krankenbett könnte die Möglichkeit, speziell hergestellte Mikrobläschen in pathologische Zielbereiche zu positionieren, zusätzlich zu weiteren therapeutischen Applikationen beitragen.
… International Journal of …, 1999
A direct comparison of extracellular and intravascular contrast agents for the assessment of myocardial perfusion was carried out in a porcine model (N = 5) with a¯ow-limiting occluder on the left anterior descending coronary artery. Rapid imaging during the ®rst pass of an extracellular or intravascular contrast agent with a saturation-recovery-prepared TurboFLASH sequence showed comparable peak contrast-tonoise enhancements in myocardial tissue regions with¯ows averaging 1.1 AE 0.2 at baseline to 4.8 AE 0.6 ml/ min/g during hyperemia. The coecient of variation between the MR estimates of blood¯ow with Gadomer-17 and the microsphere blood¯ow measurements was 11 AE 11%, while the corresponding coecient of variation for blood¯ow estimates with the extracellular CA was 23 AE 11%. Blood volume dierences between rest and hyperemia observed with the intravascular tracer were signi®cant (V vasc (rest) = 0.078 AE 0.013 ml/g, versus V vasc (hyperemia) = 0.102 AE 0.019 ml/g; p`0X05). The eects of water exchange were minimized through the choice of pulse sequence parameters to provide blood volume estimates consistent with the changes expected between rest and hyperemia. This study represents the ®rst application of multiple indicators in ®rst pass imaging studies for the assessment of myocardial perfusion. The use of an intravascular instead of an extracellular contrast agent allows a reduction of the degrees of freedom for modeling tissue residue curves and results in improved accuracy of blood¯ow estimates.
Revista española de cardiología, 2005
After a myocardial infarction, damage to the microcirculation indicates a worse prognosis. We compared the usefulness of the quantitative analysis of myocardial contrast echocardiography with intravenous injection of contrast (MCE-iv) with intracoronary injection (MCE-ic) for analyzing coronary perfusion. We studied 42 patients with a first ST-elevation myocardial infarction, single-vessel disease and a patent artery (TIMI 3, stenosis < 50%). Myocardial perfusion in segments in the infarct-related area was quantified (normalized scale 0-1) with MCE-ic (bolus of Levovist, real-time imaging, perfusion considered normal if > 0.75) and MCE-iv (perfusion of SonoVue, single-image capture in 1 out of each 6 cycles with trigger set at end-systole, perfusion considered normal if > 0.9). Perfusion was considered abnormal if 2 or more segments showed altered perfusion. Quantification with MCE-iv took 5 +/- 1 minutes. No side effects were observed. MCE-ic was normal in 141 segments (80...
Assessment of myocardial perfusion by contrast echocardiography
Revista portuguesa de cardiologia : orgão oficial da Sociedade Portuguesa de Cardiologia = Portuguese journal of cardiology : an official journal of the Portuguese Society of Cardiology, 2001
Contrast echocardiography delineates myocardial perfusion and has the potential for quantitating coronary flow and assessing myocardial viability. These applications add important physiologic information to the anatomic information readily available from conventional echocardiography. Because it can be rapidly performed at the bedside, contrast echocardiography may be valuable tool for the use in acute myocardial ischemia. When contrast echocardiography has been used after recanalization of occluded coronary arteries, the assessment of myocardial salvage conveys information concerning reflow, stunning, and prognosis, and in the case of angioplasty it provides immediate information regarding the success of the procedure. Contrast echocardiography can also assess myocardial areas at risk of irreversible damage and the presence or absence of collateral flow. Myocardial contrast echocardiography is a rapidly changing field and with the continued development of newer contrast agents and ...
Journal of the American Society of Echocardiography, 1995
A new intravenously administered ultrasound contrast agent was studied in eight dogs during intermittent coronary artery occlusion. The area of the myocardial contrast defect was compared with that of the acute wall motion abnormality induced by coronary occlusion. A close correlation was found between these two independent measures of acute myocardial ischemia. The peak change in myocardial intensity during coronary occlusion was significantly less than for the same segment before ischemia and for a remote nonischemic segment. This new, intravenously administered ultrasound contrast agent can be used to evaluate the spatial distribution of hypoperfused myocardium and should therefore prove valuable in the dinical evaluation of ischemic syndromes.
Clinical Application of Quantitative Analysis in Myocardial Contrast Echocardiography
Contrast Echocardiography in Clinical Practice, 2004
The introduction of stable microbubble contrast agents and technological advances have recently made it feasible to perform quantitative measurements of microvascular damage by myocardial contrast echocardiography (MCE). Qontrast ® is a new software system for such measurements. It includes physiological filters, global rescale, regional rescale, automatic myocardial tracking, manual ECG trigger and parametric imaging. Qontrast ® was tested on 5 pigs given sulphur hexafluoride bubbles (1 ml/min) and fluorescent microspheres (reference) after the induction of 50% and 100% stenosis of left anterior descending coronary artery. The image sequences were repeated four times using different ultrasound (US) equipment. A close correlation was found between the ratio risk area/control area by microspheres and the equivalent ratio risk area/control area (SI×b) by MCE, being approximately 0.9 for any contrast modality tested. Parametric MCE and SPECT were compared in 12 patients with recent myocardial infarction, including 119 segments. Agreement amounted to 83% (kappa: 0.53 for peak SI and 0.55 for SI×b). The sensitivity and specificity of peak SI for detecting abnormal segmental tracer uptake were 67% and 88%; the values for SI×b were 70% and 87%. Parametric MCE is a promising imaging technique for the assessment of myocardial perfusion in patients with suspected or known coronary artery disease.
Myocardial perfusion assessment with contrast echocardiography
Medical Imaging 2001: Ultrasonic Imaging and Signal Processing, 2001
Assessment of intramyocardial perfusion by contrast echocardiography is a promising new technique that allows to obtain quantitative parameters for the assessment of ischemic disease. In this work, a new methodology and a software prototype developed for this task are presented. It has been validated with Coherent Contrast Imaging (CCI®) images acquired with an Acuson Sequoia scanner. Contrast (Optison® microbubbles) is injected continuously during the scan. 150 images are acquired using low mechanical index U/S pulses. A burst of high mechanical index pulses is used to destroy bubbles, thus allowing to detect the contrast wash-in. The study is performed in two conditions: rest and pharmacologically induced stress. The software developed allows to visualize the study (cine) and to select several ROIs within the heart wall. The position of these ROIs along the cardiac cycle is automatically corrected on the basis of the gradient field, and they can also be manually corrected in case the automatic procedure fails. Time curves are analyzed according to a parametric model that incorporates both contrast inflow rate and cyclic variations. Preliminary clinical results on 80 patients have allowed us to identify normal and pathological patterns and to establish the correlation of quantitative parameters with the real diagnosis.
Clinical Cardiology, 1999
Myocardial contrast echocardiography using second-generation agents has been proposed to study myocardial perfusion. A placebo-controlled, multicenter trial was conducted to evaluate the safety, optimal dose, and imaging mode for NC100100, a novel intravenous second-generation echo contrast agent, and to compare this technique with technetium-99m sestamibi (MIBI) single-photon emission computed tomography (SPECT). In a placebo-controlled, multicenter trial, 203 patients with myocardial infarction > 5 days and < 1 year previously underwent rest SPECT and MCE. Fundamental and harmonic imaging modes combined with continuous and electrocardiogram-- (ECG) triggered intermittent imaging were used. Six dose groups (0.030, 0.100, and 0.300 microliter particles/kg body weight for fundamental imaging; and 0.006, 0.030, and 0.150 microliter particles/kg body weight for harmonic imaging) were tested. A saline group was also included. Safety was followed for 72 h after contrast injection. Myocardial perfusion by MCE was compared with myocardial rest perfusion imaging using MIBI as a tracer. NC100100 was well tolerated. No serious adverse events or deaths occurred. No clinically relevant changes in vital signs, laboratory parameters, and ECG recordings were noted. There was no significant difference between adverse events in the NC100100 (25.7%) and in the placebo group (17.9%, p = 0.3). Intermittent harmonic imaging using the intermediate dose was superior to all other modalities, allowing the assessment of perfusion in 76% of all segments. Eighty segments (96%) with normal perfusion by SPECT imaging also showed myocardial perfusion with MCE. However, a substantial percentage of segments (61-80%) with perfusion defects by SPECT imaging also showed opacification by MCE. This resulted in an overall agreement of 66-81% and a high specificity (80-96%), but in low sensitivity (20-39%) of MCE for the detection of perfusion defects. NC100100 is safe in patients with myocardial infarction. Intermittent harmonic imaging with a dose of 0.03 microliter particles/kg body weight can be proposed as the best imaging protocol. Myocardial contrast echocardiography with NC 100100 provides perfusion information in approximately 76% of segments and results in myocardial opacification in the vast majority of segments with normal perfusion as assessed by SPECT. Although the discrepancies between MCE and SPECT with regard to the definition of perfusion defects requires further investigation, MCE with NC 100100 is a promising technique for the noninvasive assessment of myocardial perfusion.