Cardiology Techniques Research Articles

Cardiac imaging in rheumatic diseases

The majority of the imaging techniques in cardiology could be applied in rheumatic diseases (RDs), such as echocardiography, single-photon emission computed tomography (SPECT), radionuclide ventriculography, angiography, cardiovascular MRI and CT. Inflammatory pericardial involvement is the most common cardiac manifestation in various forms of RD. Echocardiography is the gold standard for diagnosis of pericardial abnormalities, demonstrating location and amount of pericardial effusion. Cardiac MRI and CT can be used to assess the features of pericardial effusions and pericardial structures. In patients with valvular heart disease in RD, transoesophageal echocardiography is a superior method and offers reliable information about valve morphology, the severity of the disease and left ventricular (LV) function. In addition, cardiac MRI is a valuable tool for the evaluation of valvular stenosis and regurgitation severity. Myocardial involvement in RD is demonstrated by abnormalities in LV size and function, indicating myocardial inflammation. In these patients Doppler echocardiography and myocardial tissue imaging can provide essential diagnostic information. Both LV angiography and cardiac MRI can provide reliable information on LV size, function and mass. In patients with coronary disease associated with RD, LV ejection fraction and ventricular wall motion can be assessed by echocardiography, radionuclide ventriculography, gated SPECT and MRI. Three-dimensional (3D) echocardiography is considered superior to 2D echocardiographic techniques. Stress echocardiography is the most used method for detection of myocardial ischaemia. The only accurate visualization of the coronary arteries is by selective coronary arteriography, which remains the gold standard. Although new non-invasive techniques have been developed, including CT and MRI angiography, some limitations apply.

Myocardial Salvage

Cardiovascular magnetic resonance (CMR) is established as a major technique in clinical cardiology.1 An ongoing pipeline of new clinical indications is being fed from clinical and basic research that is throwing new light on pathophysiology of cardiovascular disease and solving clinical problems. One such advance in the last 5 years has been the clinical uptake of late-gadolinium-enhancement CMR, which yields exquisite high-resolution imaging of infarction in the necrotic (acute) or scarred (chronic) phase,2 making CMR the clinical gold standard technique for assessing infarct size3 and valuable for assessing potential regional functional recovery (viability).4 In this issue, Aletras et al5 indicate that CMR also may be used to measure myocardial salvage during acute infarction. Article p 1865 Myocardial salvage is defined as the difference between the actual and potential infarct size, the latter defined as the initial area at risk during acute coronary occlusion. It is an important concept because its measurement can be used to determine strategies to optimize management of acute myocardial infarction (MI) based on the idea that eventual clinical outcome is related to the size of infarction and that minimization is therefore beneficial. Clinical trials of minimization of infarction have a long and distinguished pedigree.6 Myocardial salvage can be measured in several ways, but some are applicable to individuals and others only to groups of patients. Thus, an intervention in acute MI can be tested for benefit by randomization of a cohort of patients to intervention or not, with follow-up of final infarct size surrogates such as ejection fraction or enzyme release. Alternatively, the same intervention can be tested for its direct effect on salvage, which allows assessment of the individual response in relation to the outcome variables and group outcomes. This strategy allows a much clearer assessment of confounding factors; …

Imaging Techniques in Nuclear Cardiology for the Assessment of Myocardial Viability

The assessment of myocardial viability has become an important aspect of the diagnostic and prognostic work-up of patients with ischemic cardiomyopathy. Although revascularization may be considered in patients with sufficient viable myocardium, patients with predominantly scar tissue should be treated medically. Patients with left ventricular dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischemia but at the same time benefit most from revascularization. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy (SPECT), whether using (201)thallium, (99m)Tc-sestamibi, or (99m)Tc-tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic and perfusion imaging with positron emission tomography (PET) radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularization. New techniques in the nuclear cardiology field, like attenuation corrected SPECT, dual isotope simultaneous acquisition (DISA) SPECT and gated FDG PET are promising and will further improve the detection of myocardial viability. Also the combination of multislice computed tomography scanners with PET opens possibilities of adding coronary calcium scoring and non-invasive coronary angiography to myocardial perfusion imaging and quantification. Evaluation of the clinical role of these creative new possibilities warrants investigation.

Heart Rate Effects on Strain and Strain Rate in Healthy Children

Based on myocardial Doppler echocardiography, regional strain (S) and strain rate (SR) can be evaluated as regional parameters of ventricular function. The use of these techniques in clinical pediatric cardiology remains a challenge. This study establishes reference values for S and SR in both systole and diastole in healthy children over a large age range and evaluates the potential relationships of demographic and echocardiographic parameters on S and SR, and, in particular, assesses the clinical effect of heart rate on S and SR in healthy children. It is shown that heart rate changes in children during growth have an important impact on both systolic and diastolic myocardial S and late diastolic SR. Therefore, to evaluate regional myocardial function in children, heart rate at rest should be considered an important factor.

Transcatheter Interventional Techniques in Pediatric Cardiology

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Kardiomyopathien

Cardiomyopathies are common causes of heart failure and sudden cardiac death. According to the WHO classification, "specific" cardiomyopathies are differentiated from "idiopathic" cardiomyopathies. Thus, this classification is primarily based on pathophysiological characteristics. The diagnostic spectrum in cardiomyopathies comprises the entire spectrum of non-invasive and invasive cardiological examination techniques. The exact verification of certain cardiomyopathies necessitates additionally investigations. For example, immunohistological and molecular biological investigations of endomyocardial biopsies may confirm inflammatory cardiomyopathy, which is often induced by viruses. Several studies have shown that specific immunomodulatory treatment options can halt the progressive course of the disease. Several gene mutations have been identified in genetic/familial dilated cardiomyopathy. First-degree relatives should be screened for early stages. Primary prevention of sudden cardiac death shows increasing superiority of the implantable defibrillator compared with pharmacological approaches (i.e. amiodarone).

Radiation-reducing planning of cardiac catheterisation

Any radiation exposition for medical purposes should be kept as low as is reasonably achievable. Mean patient radiation exposure of diagnostic cardiac catheterisation is high (16-106 Gy x cm2) and for this reason the International Commission on Radiological Protection (ICRP) recommends credentialing radiation protection training programmes. Twenty cardiologists each documented various dose parameters of 10 cardiac catheterisations, before and after a 90-minute mini-course of the ELICIT study group ("Encourage to Less Irradiating Cardiologic Interventional Techniques"), and could achieve a reduction of the mean dose-area product by 15.9+/-9.0 Gy x cm2, equivalent to 47%. The presented radiation-reducing planning of invasive cardiac catheterisation for this reason is the first one validated in clinical routine and consists of 6 standard runs--one for the left ventricle, 3 and 2 for the left (LCA) and right coronary artery (RCA), respectively--depending on anatomy and findings supplemented by 1...4 special projections. The caudal posteroanterior (PA) view documents the left coronary main stem, proximal and distal left anterior descending artery (LAD), and proximal and mid circumflex segments. The cranial PA view however is suitable for the left coronary orifice, circumflex periphery, LAD, all diagonal bifurcations, and collateral pathways towards the RCA. LCA standard angiography is completed by lateral 90 degrees/0 degrees left anterior oblique (LAO) angulation. The 60 degrees/0 degrees LAO angulation visualises the right posterolateral artery (RPL) and the RCA to its bifurcation. The more proximal one finds the bifurcation, the more the second standard cranial PA view for RCA should vary towards the cranial right anterior oblique (RAO) and finally 30 degrees/0 degrees RAO view. The efficiency of these less-irradiating angulations are improved by radiation-reducing techniques as follows: restriction to essential radiographic frames and runs, consistent collimation to the region of interest--particularly during coronary intubation--, adequate instead of best possible image quality, short skin-to-image-intensifier distance, inspiration during radiography, preference for projections that rotate out the spine, optimisation of fluoroscopy time, well-experienced and well-rested interventionists.

Human gene therapy and imaging: cardiology

This review discusses the basics of cardiovascular gene therapy, the results of recent human clinical trials, and the rapid progress in imaging techniques in cardiology. Improved understanding of the molecular and genetic basis of coronary heart disease has made gene therapy a potential new alternative for the treatment of cardiovascular diseases. Experimental studies have established the proof-of-principle that gene transfer to the cardiovascular system can achieve therapeutic effects. First human clinical trials provided initial evidence of feasibility and safety of cardiovascular gene therapy. However, phase II/III clinical trials have so far been rather disappointing and one of the major problems in cardiovascular gene therapy has been the inability to verify gene expression in the target tissue. New imaging techniques could significantly contribute to the development of better gene therapeutic approaches. Although the exact choice of imaging modality will depend on the biological question asked, further improvement in image resolution and detection sensitivity will be needed for all modalities as we move from imaging of organs and tissues to imaging of cells and genes.

Techniques in cardiology: PDA closure in children

Background: Transcatheter closure of patent ductus arteriosus (PDA) with various devices has been evaluated worldwide and in selected cases can be performed successfully, thus avoiding the morbidity associated with surgical closure. Methods and results: A 2 year old female child presented with PDA and aortic angiography showed large PDA (tubular). This defect can be closed nonsurgically by coils and devices. The coil used are normally 0.038″ having delivery system called Flipper, but this child had a large PDA and so was closed by thicker coil 0.052″ using a coil-Bioptome-sheath system, which is the first reported case from the Armed Forces. Conclusions: We report the initial experience at our center of closure of PDA with a new coil-Bioptome-sheath system.

Nuclear cardiology in the UK: do we apply evidence based medicine?

Coronary artery disease is one of the greatest health care problems facing the western industrialised nations. Each year in the UK coronary artery disease is responsible for approximately 125 000...

Analysis of current nuclear cardiology literature in MEDLINE database: a study of gated SPECT imaging using PubMed

Background Easy access to relevant clinical information is necessary for physicians to make the best decisions for patient management. The increasing amount of information available has made it difficult for physicians to retrieve up-to-date information efficiently. We sought to determine the accessibility and accuracy of indexing in the nuclear cardiology literature by conducting sample searches in the MEDLINE database on the topic of gated single photon emission computed tomography (SPECT) imaging. Methods and results The MEDLINE database was initially searched by use of both a primary and a comprehensive search strategy on PubMed for publications in English from 1994 to 2000. A total of 260 papers were retrieved from the primary search and 306 additional papers from the comprehensive search. Only 204 of the 566 citations from the combined electronic searches were truly relevant to gated SPECT. The resulting specificity index (precision) was 36%. A hand search was conducted in 11 top journals from 1994 to 2000. It yielded 81 additional citations that were missed by the PubMed search. The sensitivity index (recall) was calculated for all 11 journals. The Journal of Nuclear Cardiology had the highest rate of publication but the lowest rate of recall (44%). The clinical nuclear cardiology terminology and classifications were compared with the available Medical Subject Headings (MeSH) and MeSH Trees used for indexing in MEDLINE. Conclusions There are 6 nuclear cardiology techniques, including gated SPECT and myocardial perfusion imaging, that are not specifically indexed in the current MEDLINE database. The lack of specific MeSH headings and indexing structure results in low recall and precision for retrieval of nuclear cardiology literature. We recommend 2 additions to the MeSH Tree Structure and 6 new MeSH headings.

Overview of stress echocardiography: uses, advantages, and limitations

Responses of the heart to changes in our environment are probably even more important than how the heart functions at rest. Accordingly, stress testing with noninvasive imaging has become important for diagnosis, prognosis, and monitoring the effects of therapy. Echocardiography at rest and with stress permits characterization of global and segmental left ventricular function as well as valvular structure and function. Moreover, echocardiography can be performed during or after a number of different physical or even mental stressors. Advantages of stress echocardiography include its ready availability, relatively low capital cost, and incremental value in that it allows characterization of cardiac anatomy as well as the myocardial response to a potentially ischemic stimulus. Moreover, echocardiography has the potential to image myocardial perfusion along with wall motion and wall thickening. Substantial literature has now been accumulated on the value of stress echocardiography for the diagnosis of ischemic disease, preoperative risk assessment, and assessment of myocardial viability. Echocardiography has compared generally well with nuclear imaging techniques for the detection of angiographic coronary artery disease. Overall sensitivity, however, has been slightly less, particularly for the detection of single-vessel coronary disease, although specificity has been on average somewhat higher than nuclear cardiology techniques. Because of the potential for variability in study acquisition as well as interpretation, careful safeguards need to be employed. Specifically, meticulous technique needs to be applied to obtain high-quality images and to assure that those images are obtained promptly after treadmill exercise stress. Only readers with specific interest and expertise should interpret stress echocardiography studies. Continuing efforts need to be made to assess and minimize variability and to assure continuing quality improvement. Advances in instrumentation, including evolving technology for real-time 3-dimensional imaging, and echocardiography contrast assessment of myocardial perfusion will likely improve the sensitivity of echocardiography and further extend its usefulness.

Effective techniques for reduction of radiation dosage to patients undergoing invasive cardiac procedures.

The goal of this study was to improve radiation dose reduction techniques in invasive cardiology and after patients' radiation data had approached minimal levels, to evaluate predictors of their radiation exposure resulting from invasive cardiac procedures. Over the course of 1 year (and 1996 procedures) we minimized cinegraphic frames and runs, as well as fluoroscopy time, and trained ourselves to achieve effective fluoroscopy-saving positioning of blinds and filters toward the regions of interest. We were consequently able to reduce the mean dose-area products (DAP) for coronary angiography and angioplasty, combined interventions, high-frequency rotational atherectomy, and excimer laser angioplasty: from levels of 53.9 Gy cm(2), 79.6 Gy cm(2), 112.3 Gy cm(2), 119.4 Gy cm(2), and 168.0 Gy cm(2) as currently reported in the literature, to 12.9 Gy cm(2), 13.3 Gy cm(2), 25.9 Gy cm(2), 33.0 Gy cm(2), and 27.1 Gy cm(2), respectively. The mean DAP due to interventions in acute myocardial infarction was 38.3 Gy cm(2). DAP was influenced by body mass index, complexity of coronary artery disease, tube angulation, documented structure, coronary recanalization, emergency circumstances, and the percutaneous transluminal coronary angioplasty (PTCA) target vessel involved, but not by stent implantation. By favouring radiation-reducing cranial posteroanterior views over standard left anterior oblique views for visualization of the left anterior descending and the diagonal artery, we consequently achieved mean PTCA-DAPs of 10.4 Gy cm(2) and 8.6 Gy cm(2), respectively: levels significantly lower than those for PTCA of the right coronary artery (13.3 Gy cm(2)), left circumflex artery (13.7 Gy cm(2)), and obtuse marginal branch (16.9 Gy cm(2)). In conclusion, enhanced knowledge of radiation dose-reduction techniques significantly reduces patient radiation hazards in invasive cardiology.

Angiographic Assessment of Coronary Stenoses: A Review of the Techniques

This article reviews the fundamental techniques to quantify the physiological severity of (coronary) stenoses. Although a wide survey of different techniques and applications is provided, the focus of this review is on: 1) the assessment of the immediate effect of the stenoses on blood flow (i.e., the hemodynamic severity), and not on the assessment of the pathology of the vessel itself; 2) the flow reserve methods to defining the physiological severity of stenoses; and 3) the determination of blood flow and tissue perfusion by X-ray angiography (a short survey of other imaging modalities is provided as well). Although the practical implementation of the techniques is illustrated by applying them to coronary stenoses, most of the issues involved are of interest in other application areas (using other imaging modalities) as well. This review consists of four parts. The first part deals with the definition of stenoses severity; the second part with tracer kinetic theory necessary to determine flows by imaging; the third part focusses on (cardiac) imaging modalities, with an emphasis on X-ray angiography; and the last part illustrates the practical implementation of the techniques in cardiology.

The venous drainage of the human myocardium.

New cardiological techniques such as coronary sinus catheterization and selective catheterization of the cardiac veins permit the opening of new experimental and clinical fields, for instance in venous angiography and the reverse nourishment of myocardium which is endangered by ischemia,and also in the electrophysiological study of the components of the conduction system. New approaches in heart surgery, such as the removal of accessory pathways of the conduction system (as in WPW syndrome), necessitate the realization of the topographical relationships of the vessels in the various sections of the coronary sulci in a different way. The objective of this work is, therefore, to present comprehensive and almost new macro- and microanatomical data about the venous drainage of the myocardium via the coronary sinus and its related and unrelated (non-coronary) cardiac veins. Examination of meticulously dissected heart specimens (of individuals who had achieved old or extreme old age at the time of their death in Germany: n=250) as well as corrosion casts of adult cardiac vessels (of individuals of all ages, n=25) formed the basis for the exact description and documentation of the occurrence, frequency, origin, and courses of both the normal and anomalously developed human coronary sinus and cardiac veins. A wide range of morphological and experimental references was consulted in order to enable thorough discussion of the anatomical findings in the light of modern cardiological diagnostics and treatment. The anatomical and clinical nomenclature is presented and there is a brief comment on modern diagnostic techniques and their applications where the cardiac veins are concerned. The two principal and one compound cardiac venous system are defined and discussed with reference to the existence of both the normal and anomalous coronary sinus and cardiac vein. 1. The greater (major) cardiac venous system (2) The smaller (minor) cardiac venous system (3)The compound cardiac venous system. The microanatomy of the various proper cardiac veins is not very well explained and illustrated in old or new literature; therefore, special attention is paid in the present study to the detailed microanatomy of the cardiac venous drainage. This includes the topograpy and structural and surface anatomy of the coronary sinus (position, length and shape, diameters, area of cross-section, circumference and volume, curvature, elevation, ostial angle, enlargement, duplication, absence), and the exact enternal and internal morphological landmarks of the coronary sinus with reference to its myocardial cover, isolated myocardial belts, and "free" myocardial cords which connect the atrial and ventricular myocardium, and the atrial ostium of the coronary sinus. It is established that the frequency, distribution pattern, courses and mode of opening of the major ventricular and atrial cardiac veins and the occurrence, morphology, and efficiency of the ostial valves of the coronary sinus and its tributaries all influence the success of any selective catheter implantation and venous reperfusion technique to a great degree. There are many peculiarities of the cardiac veins which are worthy of consideration, for instance intramyocardial and aberrant courses of the anterior interventricular vein, the oblique vein of the left atrium, the posterior interventricular vein, the small cardiac vein, the posterior vein of the left ventricle, the left and right marginal veins, and the anterior cardiac veins. Various forms and courses of the intramural venous tunnel, sinus or channel of the right atrium were found and illustrated, and discussed in terms of developmental and comparative anatomy. This review incorporates a great variety of clinically significant, new morphological findings with regard to the coronary sinus and the cardiac venous system. The many anatomical peculiarities and hindrances to the catheterization of the coronary sinus and the reperfusion of (even selected) cardiac veins are documented and evaluated; the various problems which may arise in venous reperfusion due to the presence of anatomical anomalies of the coronary sinus, cardiac veins, and ostial valves (of greater or lesser efficiency) are addressed. The presentation narrows a gap in the rather incomplete knowledge of the venous drainage of the human myocardium.

Nuclear Techniques and Stress Echocardiography

<h2>Abstract</h2> Nuclear cardiology techniques (most commonly myocardial perfusion imaging, MPI) and stress echocardiography provide functional information in coronary artery disease, in contrast to the anatomical information provided by coronary angiography. The methods involve two components: <ul><li>•stress (exercise or drugs), to provoke relative hypoperfusion of myocardium supplied by stenosed coronary arteries</li><li>•imaging, to detect either the hypoperfusion (MPI) or the effect of the consequent ischaemia on myocardial function (stress echocardiography).</li></ul>MPI and stress echocardiography are inherently more sensitive and more specific than exercise ECG, and are able to localize abnormal coronary territories.

EVALUACION RADIOISOTOPICA EN CARDIOLOGIA

The current applications of nuclear cardiology techniques are reviewed. Coronary artery disease is the most important and prevalent cardiovascular problem in most developed countries and also in Chile. Different approaches can be employed for its diagnosis and prognosis, as well as for risk stratification and preoperative evaluation. Myocardial infarction assessment and ischemia recognition with radionuclide perfusion images are also reviewed, including new protocols applying functional parameters addition. Viability detection after myocardial infarction or in patients with ischemic cardiomyopathy are discussed. Stress protocols with the use of exercise or pharmacological action for ischemia production, the diagnostic value of perfusion SPECT and the use of Thallium-201, Tc-99m- Sestamibi and metabolic images with Fluorine18- Fluordeoxyglucose are also mentioned.

Hybrid revascularization feasibility in minimally invasive direct coronary artery bypass grafting combined with percutaneous transluminal coronary angioplasty in patients with acute coronary syndrome and multivessel disease

We reviewed early and midterm outcome of 11 multivessel-disease acute coronary syndrome patients treated by hybrid revascularization, i.e., initial coronary angioplasty followed by minimally invasive direct coronary artery bypass grafting. We evaluated procedural efficacy and applicability. Beginning in August 1997, hybrid revascularization was conducted in 11 multivessel-disease acute coronary syndrome patients--9 men and 2 women with a mean age of 70.3 +/- 9.3 years. Occlusion or stenosis of the target coronary artery was treated by interventional cardiologic techniques and minimally invasive direct coronary artery bypass grafting, and the early and midterm outcome evaluated. Coronary angiography was conducted in all cases at 2 weeks, 6 months, 1 and 3 years postoperatively to evaluate anastomosis and restenosis in treated coronary vessels. Initial intervention succeeded in patients with minimal residual stenosis. Subsequent minimally invasive direct coronary artery bypass grafting involved no complications. Coronary angiography early postoperatively, 6 months, 1 and 3 years later showed grafts patent without stenosis. Percutaneous transluminal coronary angioplasty was reconducted on restenotic lesions in 3 patients, 1 of whom required 3 procedures. Hybrid revascularization appears safe and effective in coronary revascularization, at least over the short term. Several patients underwent angioplasty for restenosis within 3 years after initial procedure. Overall acceptance of this hybrid method depends on long-term functional success of the 2 procedures. Its major limitation is restenosis of angioplasty sites and the need for repeat procedures.

Nuclear cardiology and electron-beam computed tomography: competitive or complementary?

Electron-beam computed tomography (EBCT) and nuclear cardiology techniques are both valuable in the noninvasive assessment of patients with suspected coronary artery disease. The techniques, however, are different in the information they provide about the patient. EBCT provides anatomic information on coronary atherosclerosis, whereas myocardial perfusion single-photon emission computed tomography assesses the physiologic significance of coronary stenosis. Because of these differences, the techniques are highly complementary. In considering the complementary nature of these methods, it is important to clarify the issues being raised. An important question in the consideration of a patient with known or suspected coronary artery disease is, What is the risk in an individual patient of developing clinical coronary artery disease? The answer to this question will determine who needs aggressive medical management. A second question in a suspected coronary artery disease patient is, What is the risk of cardiac death? As will be discussed, this risk, in general, determines the need to consider coronary revascularization. In the former question, EBCT testing and clinical assessment alone is usually sufficient, and in some cases nuclear testing can be of additional value. In answering the second question, on the basis of currently available data, the EBCT and nuclear cardiology studies appear to be operating in a complementary fashion.

Overview of stress echocardiography: Uses, advantages, and limitations

Responses of the heart to changes in our environment are probably even more important than how the heart functions at rest. Accordingly, stress testing with noninvasive imaging has become important for diagnosis, prognosis, and monitoring the effects of therapy. Echocardiography at rest and with stress permits characterization of global and segmental left ventricular function as well as valvular structure and function. Moreover, echocardiography can be performed during or after a number of different physical or even mental stressors. Advantages of stress echocardiography include its ready availability, relatively low capital cost, and incremental value in that it allows characterization of cardiac anatomy as well as the myocardial response to a potentially ischemic stimulus. Moreover, echocardiography has the potential to image myocardial perfusion along with wall motion and wall thickening. Substantial literature has now been accumulated on the value of stress echocardiography for the diagnosis of ischemic disease, preoperative risk assessment, and assessment of myocardial viability. Echocardiography has compared generally well with nuclear imaging techniques for the detection of angiographic coronary artery disease. Overall sensitivity, however, has been slightly less, particularly for the detection of single-vessel coronary disease, although specificity has been on average somewhat higher than nuclear cardiology techniques. Because of the potential for variability in study acquisition as well as interpretation, careful safeguards need to be employed. Specifically, meticulous technique needs to be applied to obtain high-quality images and to assure that those images are obtained promptly after treadmill exercise stress. Only readers with specific interest and expertise should interpret stress echocardiography studies. Continuing efforts need to be made to assess and minimize variability and to assure continuing quality improvement. Advances in instrumentation, including evolving technology for real-time 3-dimensional imaging, and echocardiography contrast assessment of myocardial perfusion will likely improve the sensitivity of echocardiography and further extend its usefulness. Copyright © 2001 by W.B. Saunders Company