Treatment strategies for patients with coronary artery disease (CAD) should be based on objective evidence of inducible ischemia in the subtended myocardium to improve clinical outcomes, symptoms, and cost-effectiveness. Fractional flow reserve (FFR) is the most verified index to-date for invasively evaluating lesion-specific myocardial ischemia. Favorable results from large clinical trials that applied FFR-guided percutaneous coronary intervention (PCI) prompted changes in coronary revascularization guidelines to emphasize the importance of this ischemia-based strategy using invasive coronary physiology. However, the frequency of functional evaluations is lacking in daily practice, and visual assessment still dominates treatment decisions in CAD patients. Despite recent efforts to integrate functional and anatomical assessments for coronary stenosis, there is considerable discordance between the 2 modalities, and the diagnostic accuracy of simple parameters obtained from current imaging tools is not satisfactory to determine functional significance. Although evidence that supports or justifies anatomy-guided PCI is more limited, and FFR-guided PCI is currently recommended, it is important to be aware of conditions and factors that influence FFR for accurate interpretation and application. In this article, we review the limitations of the current anatomy-derived evaluation of the functional significance of coronary stenosis, detail considerations for the clinical utility of FFR, and discuss the importance of an integrated physiologic approach to determine treatment strategies for CAD patients.
Coronary Angiography ; Coronary Artery Disease ; Coronary Stenosis ; Humans ; Ischemia ; Myocardial Ischemia ; Myocardium ; Percutaneous Coronary Intervention ; Physiology ; Ultrasonography, Interventional

Intracoronary stent implantation can improve coronary hemodynamics and myocardial ischemia in patients with symptomatic bridging. However, percutaneous coronary intervention for this lesion is limited due to the high prevalence of restenosis and risk of complications. We present a case of a totally occluded long-segment myocardial bridge in a patient with hypertrophic cardiomyopathy who was successfully implanted with a bare metal stent under intravascular ultrasound guidance without complications. The patient has been free of ischemic symptoms with stent patency for 10 years.
Cardiomyopathy, Hypertrophic* ; Follow-Up Studies* ; Hemodynamics ; Humans ; Myocardial Bridging ; Myocardial Ischemia ; Percutaneous Coronary Intervention* ; Prevalence ; Stents ; Ultrasonography

The peri-stent vascular changes after 2nd generation drug-eluting stent (2G DES) implantation have not been fully investigated compare to 1st generation DES (1G DES). From March 2003 to October 2010, patients receiving percutaneous coronary intervention (PCI) with either 1G or 2G DES were retrospectively included. All patients underwent intravascular ultrasound (IVUS) at post-procedure and 8-12 months after PCI. A total of 281 patients (1G DES: 201 patients with 217 lesions and 2G DES: 80 patients with 88 lesions) were enrolled. The incidence of positive peri-stent vascular remodeling (PPVR) and late-acquired incomplete stent apposition (LAISA) were investigated by IVUS images. Major adverse cardiac events (MACE) up to 3 years were also evaluated. The lesion and the stent length were shorter, and the stent size was larger in the 2G DES group. The incidences of PPVR and LAISA were lower in the 2G DES group before and after propensity score matching. However, the incidence of 3-year MACE were not different between the two groups. Independent predictors for PPVR or LAISA were stent length and 1G DES implantation. These results suggested that biocompatible stent system in 2G DES might have reduced peri-stent vascular changes.
Drug-Eluting Stents* ; Humans ; Incidence ; Myocardial Ischemia ; Percutaneous Coronary Intervention ; Propensity Score ; Retrospective Studies ; Stents* ; Ultrasonography*

Contrast echocardiography is broadly described as a variety of techniques whereby the blood pool on cardiac ultrasound is enhanced with encapsulated gas-filled microbubbles or other acoustically active nano- or microparticles. The development of this technology has occurred primarily in response to the need improve current diagnostic applications of echocardiography such as the need to better define left ventricular cavity volumes, regional wall motion, or the presence or absence of masses and thrombi. A secondary reason for the development of contrast echocardiography has been to expand the capabilities of echocardiography. These new applications include myocardial perfusion imaging for detection of ischemia and viability, perfusion imaging of masses/tumors, and molecular imaging. The ability to fill all of these current and future clinical roles has been predicated on the ability to produce robust contrast signal which, in turn, has relied on technical innovation with regards to the microbubble contrast agents and the ultrasound imaging paradigms. In this review, we will discuss the basics of contrast echocardiography including the composition of microbubble contrast agents, the unique imaging methods used to optimize contrast signal-to-noise ratio, and the clinical applications of contrast echocardiography that have made a clinical impact.
Contrast Media ; Echocardiography* ; Ischemia ; Microbubbles ; Molecular Imaging ; Myocardial Perfusion Imaging ; Perfusion Imaging ; Signal-To-Noise Ratio ; Ultrasonography

We attempted to investigate the prevalence and risk factors of carotid artery stenosis in Korea. Twenty thousand seven hundred twelve individuals who underwent carotid artery ultrasonography for health screening between March 2005 and March 2010 were retrospectively evaluated. The population was divided into four groups, according to the degree of stenosis, as Group A, below 29%; Group B, 30% to 49%; Group C, 50% to 74%; Group D, above 75%. The medical records of the individuals were investigated, and Fisher's exact test, chi-square tests, Kruskal-Wallis tests and a binary logistic regression model were used for statistical analysis. The prevalence of carotid stenosis was Group B, 5.5%; Group C, 0.9%; Group D, 0.1%. Old age, male gender, hypertension, diabetes mellitus and ischemic heart disease were significantly higher in Groups C and D (P = 0.001, 0.001, 0.001, 0.048, and 0.001, respectively). Among the males aged over 65 yr, the prevalence of carotid stenosis > or = 50% and > or = 30% were 4.0% and 18.2%, respectively. Asymptomatic carotid stenosis is not uncommon in Korea. Carotid ultrasonography is necessary for people with above-listed risk factors.
Adolescent ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Carotid Stenosis/complications/*epidemiology/ultrasonography ; Data Interpretation, Statistical ; Diabetes Mellitus, Type 2/complications ; Female ; Health Surveys ; Humans ; Hypertension/complications ; Male ; Middle Aged ; Myocardial Ischemia/complications ; Prevalence ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Factors ; Sex Factors

OBJECTIVETo analyze the correlation between myocardial ischemia and carotid atherosclerosis in hypertensive patients.

METHODSThe clinical data were collected from 85 hospitalized hypertensive patients admitted between May 2005 and September 2008 without the complication of coronary artery disease as confirmed by cardiac computed tomographic angiography (CTA). According to the results of treadmill exercise test, the patients were divided myocardial ischemia group and ischemia-free group. Univariate and multivariate analyses were used to screen the risk factors of myocardial ischemia. The correlations were analyzed between myocardial ischemia, common carotid artery intima-media thickness (IMT), Crouse score of the carotid plaque, thickness of the intraventricular septum and left artrium. The receiver operating characteristic (ROC) curves were used to evaluate the sensitivity and specificity of IMT and Crouse score in predicting the presence of myocardial ischemia in hypertensive patients.

RESULTSCarotid plaque formation was identified as the major risk factor of myocardial ischemia in hypertensive patients (OR=4.982, P=0.004). The incidence of myocardial ischemia in the hypertensive patients with carotid plaques was significantly higher than that in the patients without the plaque (Chi2=9.317, P=0.002). Myocardial ischemia in hypertensive patients was positively correlated to the thickness of the intraventricular septum (r=0.362, P=0.001) and left artrium (r=0.298, P=0.009), and the IMT of the common carotid artery was positively correlated to the thickness of the intraventricular septum (r=0.231, P=0.045). The area under cure (AUC) of the ROC curve of Crouse score was 0.726-/+0.061 in predicting the presence of myocardial ischemia in the hypertensive patients (P=0.001), and that of IMT was 0.682-/+0.061 (P=0.006).

CONCLUSIONCarotid plaque formation is the major risk factor of myocardial ischemia in hypertensive patients and shows a positive correlation to the onset of myocardial ischemia, but both the common carotid artery IMT and the Crouse score of the carotid plaque are not accurate markers for predicting myocardial ischemia in patients with hypertension.

Adult ; Aged ; Aged, 80 and over ; Atherosclerosis ; complications ; pathology ; Carotid Artery, Common ; diagnostic imaging ; pathology ; Coronary Angiography ; methods ; Female ; Humans ; Hypertension ; complications ; pathology ; Male ; Middle Aged ; Multivariate Analysis ; Myocardial Ischemia ; etiology ; pathology ; Risk Factors ; Tomography, X-Ray Computed ; Ultrasonography

The anomalous origin of the right coronary artery is a rare condition, but it has clinical importance because there have been reports of nonfatal or fatal myocardial infarction and sudden death associated with exercise for patients with this anatomy. We describe here a patient for whom 64 channel multi-detector row computed tomography was useful to identify this anomaly, and intravascular ultrasound was used to evaluate the myocardial ischemia by visualizing the coronary lumen.
Coronary Vessels ; Death, Sudden ; Humans ; Myocardial Infarction ; Myocardial Ischemia ; Ultrasonography, Interventional

This study evaluated the application of quantitative tissue velocity imaging (QTVI) in assessing regional myocardial systolic and diastolic functions in dogs with acute subendocardial ischemia. Animal models of subendocardial ischemia were established by injecting microspheres (about 300 microm in diameter) into the proximal end of left circumflex coronary artery in 11 hybrid dogs through cannulation. Before and after embolization, two-dimensional echocardiography, QTVI and real-time myocardial contrast echocardiography (RT-MCE) via intravenous infusion of self-made microbubbles, were performed, respectively. The systolic segmental wall thickening and subendocardial myocardial longitudinal velocities of risk segments before and after embolization were compared by using paired t analysis. The regional myocardial video intensity versus contrast time could be fitted to an exponential function: y=A.(1-exp(-beta.t)), in which the product of A and beta provides a measure of myocardial blood flow. RT-MCE showed that subendocardial normalized A.beta was decreased markedly from 0.99+/-0.19 to 0.35+/-0.11 (P<0.05) in 28 left ventricular (LV) myocardial segments after embolization, including 6 basal and 9 middle segments of lateral wall (LW), 8 middle segments of posterior wall (PW) and 5 middle segments of inferior wall (IW). However, there was no statistically significant difference in subepicardial layer before and after embolization. Accordingly, the ratio of A.beta of subendocardial myocardium to subepicardial myocardium in these segments was significantly decreased from 1.10+/-0.10 to 0.31+/-0.07 (P<0.05). Although the systolic wall thickening did not change 5 min after the embolization in these ischemic segments (29%+/-3% vs 31%+/-5%, P>0.05), the longitudinal peak systolic velocities (Vs) and early-diastolic peak velocities (Ve) recorded by QTVI were declined significantly (P<0.05). Moreover, the subendocardial velocity curves during isovolumic relaxation predominantly showed positive waves, whereas they mainly showed negative waves before the embolization. This study demonstrates that QTVI can more sensitively and accurately detect abnormal regional myocardial function and post-systolic systole caused by acute subendocardial ischemia.
Contrast Media ; Echocardiography/*methods ; Endocardium/physiopathology ; Microbubbles ; Myocardial Contraction/physiology ; Myocardial Ischemia/etiology ; Myocardial Ischemia/*physiopathology ; Myocardial Ischemia/*ultrasonography ; Myocardium/pathology ; Ventricular Function, Left/*physiology

BACKGROUND: The present study was aimed at defining the topological characteristics of the carotid intima-media thickness (IMT) in hypertensives, and to delineate whether the characteristics were different from those of non-hypertensive vascular risk factors. METHODS: B-mode carotid ultrasonography was performed in 33 participants who were devoid of stroke, ischemic heart disease, and carotid plaques. Longitudinal carotid images were obtained at 6 angular sites, 0 degree indexed adjacent to the external carotid artery (ECA) side from axial image crossing both internal carotid artery (ICA) and ECA, and then 45 degrees, 90 degrees, 180 degrees, 225 degrees, and 270 degrees. From the level of the flow divider, with an interval of 5 mm, up to 15 mm proximally, all the carotid IMT was measured. The IMT was then analyzed according to the levels and angles and compared according to either of hypertension or non-hypertension vascular risk factors. RESULTS: The carotid IMT showed asymmetric distributions in both the hypertension and non-hypertension risk groups. The IMT difference according to hypertension was observed better in the right carotid artery than the left. The right carotid IMT in the hypertension group showed significantly higher values at the most levels, and especially at 0 degree and 180 degrees of angular sites. CONCLUSIONS: It is important to understand the different topological characteristics of the carotid IMT according to the presence of hypertension, for a better reproducibility and predictability of the ultrasonic carotid IMT measurement.
Carotid Arteries ; Carotid Artery, External ; Carotid Artery, Internal ; Carotid Intima-Media Thickness* ; Hypertension ; Myocardial Ischemia ; Risk Factors ; Stroke ; Ultrasonics ; Ultrasonography

Image fusion is fast catching attention as Wagner pointed out in his 2006 version of the recent progress and development presented at the annual meeting of Society of Nuclear Medicine. Prototypical fusion of bone scan and radiograph was already attempted at in 1961 when Fleming et al. published an article on strontium-85 bone scan. They simply superimposed dot scan on radiograph enabling simultaneous assessment of altered bone metabolism and local bone anatomy. Indeed the parallel reading of images of bone scan and radiography, CT, MRI or ultrasonography has been practiced in nuclear medicine long since. It is fortunate that recent development of computer science and technology along with the availability of refined CT and SPECT machines has permitted us to open a new avenue to digitally produce precise fusion image so that they can readily be read, exchanged and disseminated using internet. Ten years ago fusion was performed using Bresstrahlung SPECT/CT and it is now achievable by PET/CT and SPECT/CT software and SPECT/CT hardware. The merit of image fusion is its feasibility of reliable assessment of morphological and metabolic change. It is now applicable not only to stationary organs such as brain and skeleton but also to moving organs such as the heart, lung and stomach. Recently, we could create useful fusion image of cardiac SPECT and 64-channel CT angiograph. The former provided myocardial metabolic profile and the latter vascular narrowing in two patients with coronary artery stenosis and myocardial ischemia. Arterial stenosis was severe in Case 1 and mild in Case 2.
Angiography* ; Brain ; Constriction, Pathologic ; Coronary Stenosis* ; Coronary Vessels* ; Heart ; Humans ; Internet ; Lung ; Magnetic Resonance Imaging ; Metabolism ; Metabolome ; Microcomputers* ; Myocardial Ischemia ; Nuclear Medicine ; Positron-Emission Tomography and Computed Tomography ; Radiography ; Skeleton ; Stomach ; Tomography, Emission-Computed, Single-Photon* ; Ultrasonography