Review in depth 613 Echocardiographic evaluation of coronary artery disease Yiannis S. Chatzizisisa,*, Venkatesh L. Murthyb,* and Scott D. Solomona Although the availability and utilization of other emerging technologies that are anticipated to further noninvasive imaging modalities for the evaluation of increase the clinical utility of echocardiography in the coronary artery disease have expanded over the last evaluation of patients with coronary artery disease. Coron decade, echocardiography remains the most accessible, Artery Dis 24:613–623 c 2013 Wolters Kluwer Health | cost-effective, and lowest risk imaging choice for many Lippincott Williams & Wilkins. indications. The clinical utility of mature echocardiographic Coronary Artery Disease 2013, 24:613–623 methods (i.e. two-dimensional echocardiography, stress echocardiography, contrast echocardiography) across Keywords: contrast echocardiography, coronary artery disease, emerging echocardiography methods, stress echocardiography the spectrum of coronary artery disease has been well established by numerous clinical studies. With continuing aNon-Invasive Cardiovascular Imaging Program, Cardiovascular Division, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts and advancements in ultrasound technology, emerging bDivisions of Cardiovascular Medicine, Nuclear Medicine and Cardiothoracic ultrasound technologies such as three-dimensional Radiology, University of Michigan, Ann Arbor, Michigan, USA echocardiography, tissue Doppler imaging, and speckle Correspondence to Scott D. Solomon, MD, Non-Invasive Cardiovascular Imaging tracking methods hold significant promise to further widen Program, Cardiovascular Division, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA the scope of clinical applications and improve diagnostic Tel: + 1 857 307 1960; fax: + 1 857 307 1944; accuracy. In this review, we provide an update on the role e-mail: [email protected] of echocardiography in the diagnosis, management, *Yiannis S. Chatzizisis and Venkatesh L. Murthy contributed equally to the writing and prognosis of coronary artery disease and introduce of this article. Introduction Chronic myocardial ischemia Despite numerous advances over the past several Myocardial ischemia is the result of a regional trans- decades, the diagnosis and management of coronary ient imbalance between myocardial oxygen supply artery disease remains challenging. Noninvasive imaging and demand, most often because of inadequate myo- methods have been utilized to surmount the limitations cardial perfusion as a result of atherosclerotic coronary of nonimaging techniques, such as the poor sensitivity artery disease. Hypoperfusion initiates an ischemic and specificity of exercise testing and the difficulty in cascade of intracellular changes that results in a shift in evaluation of ischemia in patients with impaired mobility cellular metabolism from glucose to fatty acids [2,4]. or left bundle branch block [1–3]. In these patients, Decreased ATP production because of decreased oxygen imaging is generally required to evaluate for the presence, supply required for aerobic metabolism results in failure extent, and severity of coronary artery disease. Because of its broad availability, lack of radiation, and relatively low Table 1 Role of echocardiography in the spectrum of coronary cost, echocardiography is an increasingly widely used artery disease examination. The clinical utility of echocardiography Coronary artery disease across the spectrum of coronary artery disease has been manifestation Echocardiography method well established by a large number of studies (Table 1). Chronic myocardial ischemia Stress echocardiography With continuing advancements in ultrasound technology, Contrast-enhanced stress echocardiography Myocardial contrast echocardiography emerging ultrasound methods such as three-dimensional Three-dimensional echocardiography echocardiography, ultrasound contrast agents, tissue Doppler tissue imaging Doppler imaging, and speckle tracking methods hold Speckle tracking imaging Acute coronary syndrome Two-dimensional resting echocardiography significant promise to further widen the scope of clinical Stress echocardiography applications and improve diagnostic accuracy. Myocardial contrast echocardiography Speckle tracking imaging The purpose of this review is (i) to provide an update on Complications of myocardial Two-dimensional resting echocardiography infarction Contrast-enhanced two-dimensional the role of echocardiography in the diagnosis, management, echocardiography and prognosis of coronary artery disease and (ii) to Risk stratification Two-dimensional resting echocardiography Stress echocardiography introduce emerging technologies that are anticipated Myocardial viability Dobutamine stress echocardiography to further increase the clinical utility of echocardio- Myocardial contrast echocardiography graphy in the evaluation of patients with coronary artery Strain imaging Ischemic cardiomyopathy Two-dimensional resting echocardiography disease. 0954-6928 c 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins DOI: 10.1097/MCA.0000000000000028 Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. 614 Coronary Artery Disease 2013, Vol 24 No 7 Fig. 1 Biomarkers Chest pain EKG EKG changes Systolic dysfunction Echo/MRI Ischemia Diastolic dysfunction PET Metabolic disorders Perfusion defect Nuclear/Echo MRI/CTA Time Ischemic cascade and the role of standard imaging modalities in the assessment of each element of the cascade. CTA, computed tomography angiography; EKG, electrocardiography; PET, positron emission tomography. of calcium reuptake into the sarcoplasmic reticulum. As a technical skill levels on the part of the sonographer. result, diastolic dysfunction is the initial manifestation, Ultrasound contrast may be administered to improve later followed by systolic dysfunction and repolarization visualization of wall motion abnormalities. Hemodynamic abnormalities seen as ST-segment changes on the surface monitoring (heart rate and blood pressure) is also per- ECG. Chest pain is a late manifestation of this cascade. formed. Figure 3a presents the protocol used for treadmill The severity of left ventricular dysfunction, ECG changes, stress echocardiography. Upright or supine bicycle ex- and clinical presentation are dependent on the extent and ercise enables imaging at peak exercise, thereby increasing severity of hypoperfusion. Figure 1 presents the ischemic the sensitivity of the method by reducing the possibility cascade and the role of standard noninvasive imaging of resolution of ischemia between the end of exercise and modalities in assessing each element of this cascade. the start of imaging. Standard echocardiography methods can provide impor- For patients who are not able to exercise or for the tant information when the hypoperfusion results in assessment of myocardial viability, pharmacological stress ischemia and systolic dysfunction before the onset of echocardiography with sympathomimetics (i.e. dobuta- ECG changes, or clinical symptoms. The appropriate use mine) or vasodilators (i.e. dypiradamole, adenosine) is criteria of echocardiography in chronic myocardial ische- preferred. Most commonly, increasing rates of dobuta- mia are summarized in Table 2 and Fig. 2 [5]. mine infusion to a peak dose of 40 mcg/kg/min may be supplemented by atropine in divided doses up to 2 mg to Stress echocardiography achieve the target heart rate (i.e. 85% of the age- In severe cases of chronic myocardial hypoperfusion, predicted maximum heart rate). Dobutamine stimulates myocardial ischemia may result in decreased regional or adrenoreceptors in the myocardium, inducing positive global systolic function [6]. More commonly, wall motion inotropic and chronotropic effects, thereby increasing and wall thickening abnormalities are observed only when myocardial oxygen demand and resulting in ischemia and ischemia is induced by exercise or pharmacologic stress. myocardial systolic dysfunction in regions subtended by coronary branches downstream of flow-limiting lesions. Stress echocardiography techniques Figure 3b presents the commonly used protocol for Stress echocardiography can be performed with exercise or dobutamine stress echocardiography. pharmacologic agents, most commonly dobutamine [3,7]. Common exercise protocols include treadmill and upright Vasodilator agents are less commonly used for pharma- or supine bicycle exercise. With treadmill exercise, stress cologic stress echo. These agents stimulate adenosine echocardiography images are obtained at baseline before receptors, which causes coronary vasodilation. In the the initiation of exercise and after exercise within the first presence of severe or extensive coronary disease, this minute after the conclusion of exercise. Rapid acquisition may result in coronary steal and subsequent systolic of high-quality images requires careful planning and high dysfunction. In some cases, the secondary effect of Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. Echocardiography and coronary artery disease Chatzizisis et al. 615 Table 2 Echocardiography appropriate use criteria in coronary artery disease [5] Chronic myocardial ischemia Stress echocardiography Low pretest probability of CAD ECG uninterpretable or unable to exercise Intermediate pretest probability of CAD ECG interpretable