Expanding the noninvasive coronary physiology assessment with transthoracic Doppler echocardiography.
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Arteries↗
Biomedical subjects
S Iliceto
Publications and source records attributed to S Iliceto.
Detection of early impairment of coronary flow reserve in patients with systemic sclerosis.
OBJECTIVE: To investigate whether coronary flow reserve (CFR), measured by a new non-invasive method, is impaired early in patients with systemic sclerosis (SSc) and whether CFR impairment correlates with clinical or functional measures, or both. METHODS: 27 patients with SSc without clinical evidence of ischaemic heart disease and 23 control group subjects matched for age and sex were studied. CFR was evaluated in the left anterior descending coronary artery (LAD) with a new non-invasive method: contrast (Levovist) enhanced transthoracic Doppler during adenosine infusion. The pulsed wave Doppler examination of blood flow velocity was recorded in the LAD at rest and after maximum vasodilatation by adenosine infusion. RESULTS: In patients with SSc, without clinical evidence of ischaemic heart disease, CFR was impaired (p=0.0001). 14/27 patients with SSc had severe reduction of the CFR (< or =2.5) compared with controls (p=0.002). A non-significant trend between mean CFR and the severity and duration of the disease was also seen. CONCLUSIONS: CFR is often reduced in patients with SSc, suggesting early preclinical cardiac involvement in SSc. This impairment in coronary microvasculature is detectable by a non-invasive echocardiographic method and in this study was more common in the diffuse form of SSc.
Adult↗
Prevention of thromboembolism in patients with mitral stenosis and associated atrial fibrillation: effectiveness of low intensity (INR target 2) oral anticoagulant treatment.
Mitral stenosis (MS) in association with atrial fibrillation (AF) is a clinical condition at high risk for systemic thromboembolism. Although oral anticoagulants greatly reduce the incidence of thromboembolism in these patients, the optimal intensity of treatment has never been tested in specific clinical trials, and current recommendations are derived from studies of nonrheumatic AF. In this study we tested the effectiveness of two different intensities. The study design was carried out as an open randomized prospective study in an anticoagulation clinic. We randomized 103 patients with MS and AF to a low (target INR = 2) or moderate (target INR = 3) anticoagulation regimen. The primary end points were systemic thromboembolism, major bleeding and vascular death. During a mean follow-up of 4.5 years, 1 systemic embolism occurred in the low intensity group (0.41 per 100 pt/yrs, CI 0.01-2.3), and 1 minor stroke occurred in the moderate intensity group (0.40 per 100 pt/yrs, CI 0.01-2.3; p = ns). Major bleeding occurred in 8 patients, with 3 in the low intensity (1.25 per 100 pt/yrs) and 5 in the moderate intensity group (2.0 per 100 pt/yrs, Incidence Rate Ratio 0.6, CI 0.1-3.1; p = ns). Total events (systemic embolism, major bleeding and vascular death) occurred in 7 low intensity patients and 8 moderate intensity patients. As expected, minor bleeding was more frequent in the moderate intensity group of patients, who actually had more intense treatment and required closer monitoring of oral anticoagulant treatment. These data suggest that low intensity anticoagulation, as performed in an anticoagulation clinic, is effective and safe in high risk patients with MS and AF.
Acenocoumarol↗
Contrast-enhanced harmonic color Doppler for left ventricular opacification: improved endocardial border definition compared to tissue harmonic imaging and optimization of methodologyin patients with suboptimal echocardiograms.
OBJECTIVES: This study compared the efficacy of contrast-enhanced harmonic color Doppler (C-HCD) and tissue harmonic imaging (THI) for left ventricular endocardial border delineation and explored the optimal methodology of C-HCD in patients with suboptimal echocardiograms. BACKGROUND: The value of C-HCD in improving endocardium remains unknown. Effects of harmonic velocity-encoded color Doppler (HVD) and harmonic power Doppler (HPD) as well as contrast administration and image acquisition modalities on left ventricular opacification (LVO) have not been established. METHODS: One hundred (50 HVD, 50 HPD) patients with suboptimal echocardiograms during conventional fundamental echocardiography were studied with THI and C-HCD using Levovist. Each patient underwent different random contrast administration and image acquisition modalities. Endocardial border definition score index (EBDI), blooming artifacts, contrast destruction, and salvage of suboptimal echocardiograms were calculated in each patient after contrast enhancement. RESULTS: EBDI improved from 2.05 +/- 0.61 in THI to 2.73 +/- 0.48 in HVD, and 1.98 +/- 0.73 in THI to 2.69 +/- 0.51 in HPD (both P < 0.001). The conversion of a nondiagnostic image from fundamental echocardiography to an optimal diagnostic image was 33 (33%) patients in THI compared to 77 (77%) patients in C-HCD (P < 0.001). Blooming artifacts were seen more commonly in HVD than HPD, intermittent than continuous image acquisition, and bolus than infusion administration (all P < 0.001). There was less contrast destruction in intermittent compared with continuous image acquisition (P < 0.001). Contrast destruction was similar in HVD and HPD, bolus and infusion injection of contrast. The highest salvage rate of a nondiagnostic image from THI to an optimal diagnostic image was 45.5% and 42.4% in HPD mode, with intermittent image acquisition during bolus and infusion contrast administrations. CONCLUSIONS: C-HCD seems more effective in demonstrating improved endocardial border definition compared to THI. HPD has less blooming artifacts compared with HCD. The optimal method for LVO was to use HPD with intermittent image acquisition during bolus or infusion administration of Levovist.
Adolescent↗
Quantification of left ventricular function with contrast-enhanced harmonic colour Doppler and a semiautomated boundary detection algorithm in technically difficult patients: feasibility, accuracy, and inter-observer variability.
AIMS: Patients with poor quality echocardiograms impede the application of available automatic boundary detection technologies. Tissue harmonic imaging and contrast media can allow optimal differentiation of left ventricular blood pool and tissue, making it possible to utilize automatic boundary detection software for automatic non-operator-dependent computation of left ventricular volumes. We integrated contrast-enhanced harmonic colour Doppler with a semiautomated boundary detection algorithm to explore the feasibility, accuracy and inter-observer variability for left ventricular volume assessment in technically difficult patients. METHODS AND RESULTS: Twenty-six patients with more than two segments not clearly visualized in tissue harmonic imaging were studied with contrast-enhanced harmonic colour Doppler using Levovist. Twenty patients (77%) achieved full left ventricular contrast filling without apparent blooming artefacts. Contrast-enhanced harmonic colour Doppler-automatic boundary detection was successfully implemented in these 20 patients, despite three (15%) in which it was not possible to acquire more than three cardiac cycles' values. Contrast-enhanced harmonic colour Doppler-automatic boundary detection measurements agreed closely with the manually drawn data. Among the three independent readers in the three techniques, the best correlation, lowest SEE, smallest limits of agreement and inter-observer variability were obtained in contrast-enhanced harmonic colour Doppler-automatic boundary detection. CONCLUSION: Contrast-enhanced harmonic colour Doppler-automatic boundary detection was feasible and accurate in estimation of left ventricular volume and function in patients with poor acoustic windows. This technique significantly reduced inter-observer variability, thus improving reliability and confidence of investigators in left ventricular function assessment. Contrast-enhanced harmonic colour Doppler-automatic boundary detection may have great potential in clinical evaluation of left ventricular volume and function, especially when on-line software is available.
Algorithms↗
Clinical applications of contrast echocardiography.
BACKGROUND: Contrast media, used in conjunction with newly developed echocardiographic techniques, can currently be used in several clinical settings: (1) the study of myocardial perfusion, (2) delineation of the endocardial border in technically difficult echocardiographic examinations, and (3) enhancement of low-intensity blood flow, especially coronary blood flow, to study coronary flow reserve. METHODS: Published studies were reviewed to identify the advantages of associating contrast perfusion with classic or new echocardiographic and ultrasonographic imaging techniques in the study of myocardial perfusion and coronary artery flow. RESULTS: Several studies demonstrated the usefulness of contrast echocardiography, even in patients with a bad acoustic window, in evaluating opacification of the left ventricle or in enhancing echocardiographic color Doppler studies of coronary flow and coronary flow reserve. Preliminary results of transthoracic echocardiographic studies of myocardial perfusion are described. CONCLUSIONS: The clinical applications of contrast echocardiography are effective in exploiting examinations that provide poor diagnostic information (ventricular cavity opacification) or in obtaining new physiopathologic data (microvascular opacification/perfusion and coronary flow reserve). The evaluation of coronary flow reserve by contrast-enhanced transthoracic Doppler ultrasonography is an attractive new diagnostic modality that points the way toward important new clinical applications of contrast echocardiography. This technique is useful in evaluating the severity of coronary artery disease of the left anterior descending coronary artery and in all clinical conditions in which the effects of therapeutic interventions aimed at improving coronary flow reserve need to be monitored.
Blood Flow Velocity↗
[Medico-legal features of early discharge in acute myocardial infarction and chest pain].
The authors' aim is to outline some of the main medico-legal problems in cardiology, especially those regarding the premature hospital discharge of patients with undefined chest pain and/or with acute myocardial infarction. After a brief overview on the etiology and clinical definition of chest pain and myocardial infarction, premature hospital discharge is defined and the incidental medico-legal risks that physicians operating in such situations are exposed to are pointed out. Next, the profiles regarding both the positive and negative views of professional medical responsibility are described. In the negative frame, the authors outline the most frequent civil and penal aspects of the unpremeditated responsibility. Then the physician's error, in both qualitative (generic or specific guilt) and quantitative (degree) terms, is considered; particularly, negligence, imprudence and inexperience, as qualitatively accepted meanings of generic guilt, are dealt with by adopting illustrative cases settled in the light of the right legal interpretation. The phases of the diagnostic or prognostic error are evaluated, and clinical protocols, as a reference parameter for the identification of error, are considered. Lastly, the problem of causality, essential condition for the judgment about the professional responsibility, and the problem of the patient's consent, including an evaluation of the legal capability or incapability about the declaration of consent, are examined closely.
Chest Pain↗
Ischemia-reperfusion injury at the microvascular level: treatment by endothelin A-selective antagonist and evaluation by myocardial contrast echocardiography.
BACKGROUND: The purpose of this study was to verify whether endothelin A-antagonist administration at the time of coronary reperfusion preserves postischemic microvasculature and whether myocardial contrast echo (MCE) is able to detect pharmacologically induced changes in microvascular reflow. METHODS AND RESULTS: Twenty dogs underwent 90 minutes of LAD occlusion (OCC) followed by 180 minutes of reperfusion (RP). Five minutes before LAD reopening, an intravenous bolus (5 mg/kg) of LU 135252 was given in 10 dogs and vehicle in the remaining 10. At baseline (BSL), OCC, and 90 and 180 minutes of RP, microvascular flow (BF) was assessed by microspheres, and MCE was performed with intravenous echo contrast. MCE videointensity and BF were expressed as risk area/control ratio. Myocardial thickness of the risk area was calculated by 2D echo. No differences in BF between the 2 groups were observed at BSL, OCC, and 90 minutes of RP. At 180 minutes of RP, BF was decreased in controls (70+/-7.4% of BSL; P:<0.005 versus BSL) and preserved in LU 135252-treated animals (89+/-4% of BSL; P=NS versus BSL; P<0.05 versus controls). Videointensity at MCE closely followed the changes in BF observed in both groups throughout the protocol. Myocardial thickness at 180 minutes of RP increased to 138.6+/-9.9% of BSL in controls and remained at 108.9+/-7.4% of BSL in treated dogs (P<0.05). CONCLUSIONS: Endothelin A-antagonist treatment at the time of reperfusion significantly limited the progressive decrease in postischemic microvascular reflow and the increase in myocardial thickness. MCE allowed a reliable evaluation of pharmacologically induced changes in microvascular flow.
Animals↗
Myocardial infarction and left ventricular remodeling: results of the CEDIM trial. Carnitine Ecocardiografia Digitalizzata Infarto Miocardico.
Left ventricular dilatation after acute myocardial infarction (MI) is a powerful predictor of progressive functional deterioration, culminating in heart failure and death. The most important determinants of post-MI left ventricular remodeling are the size of the infarct, the degree of residual stenosis in the infarct-related artery, and the viability of the infarct zone. In addition to reperfusion therapy and angiotensin-converting enzyme inhibition, metabolic intervention with L-carnitine may represent a therapeutic approach for preventing left ventricular dilatation and preserving cardiac function. Ongoing studies with early metabolic intervention with carnitine in the acute phase of infarction may prove successful in protecting the microcirculation against ischemic damage and enhancing its ability to respond to blood flow resumption. The results of the multicenter, randomized, double-blind Carnitine Ecocardiografia Digitalizzata Infarto Miocardico (CEDIM) trial suggest that the early and long-term administration of L-carnitine attenuates progressive left ventricular dilatation after acute anterior MI. Results show significant, consistent reductions in end-diastolic volume and end-systolic volume in patients who received L-carnitine compared with placebo. The ongoing CEDIM-2 trial (projected 4000 patients with acute MI) will assess the efficacy of L-carnitine in reducing the combined incidence of death and heart failure at 6 months. In addition to standard reperfusion therapy and angiotensin-converting enzyme inhibition, metabolic intervention with L-carnitine may be a therapeutic approach for preventing left ventricular dilatation and preserving cardiac function by limiting infarct size, decreasing residual stenosis in the infarct-related artery, and increasing viability of the infarct zone.
Cardiomyopathy, Dilated↗
Cardiac dysfunction in acromegaly: evidence by pulsed wave tissue Doppler imaging.
OBJECTIVE: To verify whether the accuracy of data on myocardial function provided by pulsed-wave tissue Doppler imaging (PWTDI), a new echocardiographic application that allows quantitative measurements of myocardial wall velocities, could help towards a better understanding of the natural history of acromegalic cardiomyopathy. DESIGN: Eighteen patients with active acromegaly (ten men and eight women; mean age 48.0+/-15.0 years) with no other detectable cause of heart disease underwent PWTDI. Thirteen healthy individuals matched for age and body mass index acted as a control group. METHODS: Ejection fraction (EF), transmitral early/late diastolic velocity (E/A) ratio and isovolumic relaxation time (IVRT) were measured by conventional echocardiography; systolic peak (Sv) and early (Ev) and late (Av) diastolic peak velocities, Ev/Av ratio and regional IVRT (IVRTs) were obtained by PWTDI. RESULTS: All patients showed appreciably abnormal left ventricular global diastolic function represented by prolongation of the IVRT (P<0.001). Using PWTDI we found a prolongation of IVRTs and inversion of the Ev/Av ratio. In addition, the Ev/Av ratio proved to be significantly negatively correlated with IVRT; this correlation was not present in the case of the E/A ratio. Furthermore, a decrease in Sv was detected in the basal segment of the lateral wall (P<0.01), which had the greatest degree of diastolic dysfunction. CONCLUSIONS: PWTDI confirmed the acknowledged diastolic dysfunction that accompanies acromegalic cardiomyopathy and highlighted the greater sensitivity of regional PWTDI with respect to global Doppler diastolic indexes. Furthermore, by revealing an impairment of regional systolic function in presence of a normal EF, the findings with PWTDI contradicted the largely accepted theory that systolic function remains normal for several years in patients affected by acromegalic cardiomyopathy.
Acromegaly↗
Microvascular damage during myocardial ischemia-reperfusion: pathophysiology, clinical implications and potential therapeutic approach evaluated by myocardial contrast echocardiography.
During myocardial ischemia produced by coronary occlusion, coronary microvessels and cardiac myocytes undergo progressive functional and structural changes. The prompt reopening of the epicardial vessel is the main therapeutic strategy to limit the vascular and cellular damage. However, the full benefit of reperfusion can be limited by progressive microvascular obstruction and cell death occurring after the reestablishment of flow. During ischemia-reperfusion, preservation of the integrity of the coronary microvasculature is a fundamental prerequisite to ensuring myocardial viability. Therefore, therapeutic approaches should be developed to prevent and treat microvascular impairment resulting from ischemia-reperfusion. Also, given the importance of the assessment and treatment of post-reperfusion disorders of coronary microvasculature, a diagnostic tool able to evaluate the structural and functional status of the microcirculation in vivo is needed. Myocardial contrast echocardiography has been demonstrated to be extremely useful in this setting. In this review, the anatomic and functional characteristics of the coronary microcirculation are described during normal conditions, as well as in the presence of ischemia-reperfusion injury. The role of myocardial contrast echocardiography in the assessment of microvascular dysfunction and specific potential therapeutic approaches to the treatment of microvascular damage during ischemia and after reperfusion are also discussed.
Animals↗
Transmural heterogeneity of myocardial contraction and ischemia. Diagnosis and clinical implications.
Myocardial contraction behaves heterogeneously, being greater in subendocardial than in subepicardial layers. Similarly, during acute myocardial ischemia or infarction, the subendocardium is the first myocardial layer to suffer. Conventional two-dimensional echocardiography cannot distinguish the transmural extension of myocardial ischemia or infarction, showing akinesia also when only the subendocardium is affected. Novel ultrasonographic techniques (like tissue characterization with integrated backscatter or Doppler tissue imaging) and nuclear magnetic resonance tagging can investigate myocardial contraction in different transmural layers and distinguish subendocardial from transmural ischemia or infarction. With the advent of thrombolysis and primary angioplasty in the acute phase of myocardial infarction a correct diagnosis of the extension of myocardial necrosis cannot ignore its transmural wavefront development. The salvage of the subepicardial layer does not give direct information on overall myocardial thickening but is one of the major determinants of overall left ventricular dysfunction and size. Although it is still necessary to investigate this phenomenon, new ultrasonographic techniques give us important information and more opportunities to appropriate diagnosis and future treatment of cardiac patients.
Animals↗
Early administration of verapamil after thrombolysis in acute anterior myocardial infarction. Effect on left ventricular remodeling and clinical outcome. VAMI Study Group. Verapamil Acute Myocardial Infarction.
BACKGROUND: The administration of verapamil during the reperfusion phase of acute myocardial infarction can reduce the extent and severity of microvessel damage and limit myocardial dysfunction. We aimed at investigating the effect of early verapamil administration on left ventricular remodeling and the clinical evolution after myocardial infarction. METHODS: Eighty-eight patients with first acute anterior myocardial infarction thrombolysed < 4 hours from symptom onset were enrolled in a multicenter, randomized, double-blind, controlled study of verapamil administration (5 mg i.v. + 2 microg/kg/min over 24 hours). Echocardiographic end-diastolic (EDV) and end-systolic (ESV) left ventricular volumes were assessed by biplane Simpson's rule. RESULTS: At 90 days, EDV in the verapamil and placebo groups was respectively 88.9 +/- 27.8 and 95.8 +/- 30.7 ml (p = 0.11), ESV was 52.6 +/- 22.7 and 57.7 +/- 25.4 ml (p = 0.18). There was no change over time in the verapamil group (day 3 vs day 90: EDV 85.0 +/- 17.7 vs 88.9 +/- 27.8 ml, p = NS; ESV 48.7 +/- 14.1 vs 52.6 +/- 22.7 ml, p = NS) while left ventricular volume increased in the placebo group (day 3 vs day 90: EDV 87.6 +/- 21.1 vs 95.8 +/- 30.7 ml, p = 0.03; ESV 52.0 +/- 16.9 vs 57.7 +/- 25.4 ml, p = 0.08). NYHA functional classes were differently distributed at 30 and 90 days (chi2 = 0.009 and 0.07), with a lower prevalence of classes II and III in the verapamil group (p = 0.03). CONCLUSIONS: The early intravenous administration of verapamil in thrombolysed patients can reduce left ventricular remodeling and NYHA functional class after acute anterior myocardial infarction.
Calcium Channel Blockers↗
Effects of acute myocardial ischemia on intramyocardial contraction heterogeneity: A study performed with ultrasound integrated backscatter during transesophageal atrial pacing.
BACKGROUND: [corrected] Subendocardial thickening is greater than subepicardial thickening and acute myocardial ischemia mainly impairs the former. Integrated backscatter cyclic variations (IBScv) reflect regional myocardial contractility and are blunted during myocardial ischemia. We hypothesized that stress-induced myocardial ischemia mainly affects subendocardial IBScv. METHODS AND RESULTS: Multiplane transesophageal echocardiography and simultaneous atrial pacing were performed in 12 patients without coronary artery disease (CAD) and in 25 with significant CAD. In a transgastric 2-chamber view, we calculated IBScv in subendocardium and subepicardium and a heterogeneity index, both at rest and at peak-pacing. In 27 myocardial segments of patients with normal coronary arteries, and in 16 myocardial segments supplied by coronary artery without significant stenosis in patients with CAD, there was a transmural gradient of IBScv at rest and the heterogeneity index did not change during all the protocol steps. In the 53 myocardial segments related to a significantly narrowed coronary artery, the transmural gradient of IBScv, present at rest, significantly decreased at peak-pacing because of subendocardial blunting, but promptly recovered 5 seconds after pacing interruption. Moreover, the myocardial thickening at rest and peak pacing correlated with the subendocardial IBScv behavior and not with the subepicardial one. CONCLUSIONS: IBScv are greater in the subendocardium than in the subepicardium. Atrial pacing stress test does not affect IBScv in segments supplied by nonstenotic coronary arteries, whereas it affects segments supplied by diseased coronary arteries, blunting exclusively subendocardial IBScv. Heterogeneity of IBScv intramyocardial changes caused by stress-induced ischemia must be taken into account when using IBScv for investigating myocardial ischemia.
Acute Disease↗
New noninvasive method for coronary flow reserve assessment: contrast-enhanced transthoracic second harmonic echo Doppler.
BACKGROUND: We tested the hypothesis that blood flow velocity could be recorded in the left anterior descending coronary artery (LAD) during transthoracic echocardiography by use of second harmonic echo Doppler modality along with contrast enhancement (intravenous Levovist) at rest and after pharmacologically induced maximal vasodilation to assess coronary flow reserve (CFR) with a totally noninvasive approach. METHODS AND RESULTS: Fifty-six consecutive patients undergoing coronary angiography underwent transthoracic contrast-enhanced pulsed-wave Doppler recording of blood flow velocity in the LAD by use of harmonic color Doppler as a guide at rest and after maximal vasodilation by dipyridamole infusion. Contrast enhancement with the harmonic mode greatly improved the success rate of recording adequate pulsed-wave Doppler signal in the LAD. CFR was (mean+/-SD) 1.54+/-0.7 in patients with (group 1) and 2. 79+/-0.9 in patients without (group 2) significant LAD stenosis (lumen narrowing >70%) (P<0.001); sensitivity and specificity in detecting significant LAD stenosis were 86% and 90%, respectively. There was close agreement between CFRs determined by this new method and intracoronary Doppler flow wire. CONCLUSIONS: Contrast-enhanced transthoracic echo Doppler with the harmonic mode is a feasible and promising technique for assessing CFR in a totally noninvasive way.
Adult↗
Contrast-enhanced transthoracic second harmonic echo Doppler with adenosine: a noninvasive, rapid and effective method for coronary flow reserve assessment.
OBJECTIVES: The purpose of this study is to evaluate the feasibility in detecting blood flow in the left anterior descending coronary artery (LAD) using transthoracic color Doppler (CD) imaging (in both second harmonic and fundamental mode) along with contrast enhancement and to verify if this new noninvasive method along with adenosine is safe, rapid and effective in assessing coronary flow reserve (CFR). BACKGROUND: Feasibility of contrast-enhanced transthoracic Doppler recording (in both second harmonic and fundamental mode) of blood flow velocity in the LAD has not been assessed. Adenosine has a greater vasodilator potency and more favorable kinetics than dipyridamole and thus it can be more suitable for assessing CFR in conjunction with this method. METHODS: Sixty-one patients with angiographically patent LAD underwent CD (both in fundamental and harmonic mode) as well as color-guided pulsed wave (PW) Doppler recording of blood flow velocity in the distal LAD before and after intravenous contrast injection. A second group of patients (n = 77), undergoing coronary angiography, was submitted to transthoracic contrast-enhanced PW Doppler recording of blood flow velocity in the LAD using harmonic CD as a guide, at rest and during adenosine-induced hyperemia. RESULTS: Harmonic CD along with echo contrast consistently improved blood flow detection in the LAD; the success rate in detecting flow of optimal quality was 88% with this approach, whereas it was 11% and 16% with CD in fundamental mode, respectively, before and after contrast. Pulsed wave Doppler results paralleled those of harmonic CD (p < 0.001 contrast harmonic vs. fundamental). In the second group of patients coronary angiography revealed 0% to <40% stenosis in 24 patients (group I), > or =40% to < or =75% in 17 patients (group II) and >75% stenosis in 34 patients (group III). There was a significant difference in CFR among the three groups of patients; CFR for peak diastolic velocity was (mean +/- SD): 2.88+/-0.7 (group I), 2.09+/-0.5 (group II) and 1.51+/-0.5 cm/s (group II) (p < 0.05 group I vs. both group II and group III; p < 0.05 group II vs. group III). The whole examination took less than 10 min. CONCLUSIONS: Contrast-enhanced second harmonic Doppler recording of blood velocity in the LAD is highly feasible and in combination with adenosine it is a rapid, safe and effective method for assessing CFR ratio.
Adenosine↗
Validation of a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) for the evaluation of coronary flow reserve: comparison with intracoronary Doppler flow wire.
OBJECTIVES: We tested the hypothesis that coronary flow reserve (CFR) in the left anterior descending coronary artery (LAD) as assessed by a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) is in agreement with CFR measurements assessed by intracoronary Doppler flow wire. BACKGROUND: Contrast-enhanced transthoracic second harmonic echo Doppler is a novel noninvasive method to detect blood flow velocity and reserve in the LAD. However, it has not yet been validated versus a gold-standard method. METHODS: Twenty-five patients undergoing CFR assessment in the LAD by Doppler flow wire were also evaluated by contrast-enhanced transthoracic Doppler to record blood flow in the distal LAD at rest and during hyperemia obtained by adenosine i.v. infusion. In five patients CFR was evaluated twice (before and after angioplasty). RESULTS: As a result of the combined use of i.v. contrast and second harmonic Doppler technology, feasibility in assessing coronary flow reserve equaled 100%. The agreement between the two methods was high. In fact, in all but five patients the maximum difference between the two CFR measurements was 0.38. Overall, the prediction (95%) interval of individual differences was -0.69 to +0.72. Reproducibility of CFR measurements was also high. The limits of the agreement (95%) between the two measurements were -0.32 to +0.32. CONCLUSIONS: Coronary flow reserve in the LAD as assessed by contrast-enhanced transthoracic echo Doppler along with harmonic mode concurs very closely with Doppler flow wire CFR measurements. This new noninvasive method allows feasible, reliable and reproducible assessment of CFR in the LAD.
Adenosine↗
Effects of acute ischaemia on intramyocardial contraction heterogeneity; new ultrasound technologies to study an old phenomenon.
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Acute Disease↗