Contrast-Enhanced Harmonic Color Doppler for Left Ventricular Opacification: Improved Endocardial Border Definition Compared to Tissue Harmonic Imaging and Optimization of Methodology in 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.     

Stimulated Acoustic Emission Nonbackscatter Contrast Effect of Microbubbles Seen with Harmonic Power Doppler Imaging

Transient imaging has been introduced to enhance the signal intensities when using echo contrast agents. However, this phenomenon is not clearly understood. To evaluate the mechanisms of this phenomenon, isolated pig hearts were investigated with different echo imaging techniques in the beating, working heart as well as in an asystolic state without any motion of the heart. The hearts of five German farm pigs (21 ± 2.5 kg) were surgically explanted and inserted in an artificial circulation providing physiological flow and pressures. Levovist in the dosage of 0.05–0.3 g was injected into the left atrium and contrast effects evaluated in the left ventricular (LV) cavity and in the myocardium with an ultrasound imager (ATL, HDI 3000) equipped with a prototype software for harmonic imaging. Harmonic B-scans and power Doppler registrations were performed with continuous and intermittent recordings (ECG triggered at end-systole) in the beating heart and using an external trigger in the asystolic heart in which perfusion was interrupted for 20 seconds. In the beating pig heart, transient harmonic power Doppler imaging provided intensive opacification of the LV cavity and visible myocardial uptake when ECG triggering was performed. In the asystolic pig heart, with uninterrupted perfusion, both triggered and nontriggered registrations showed contrast signals in the LV cavity and in the myocardium. These findings cannot be explained with the known physics of ultrasound contrast media. Stimulated acoustic emission occurring during disintegration of the microbubbles in the acoustic field would explain this phenomenon, which has not yet been described for Levovist.     

Identification of cardiac abnormal structures with harmonic power Doppler contrast echocardiography

We describe two cases in which echocardiographic image enhancement with an intravenous contrast agent using harmonic power Doppler (HPD) imaging established the diagnosis of abnormal structures in the left ventricle (LV).     

Harmonic Power Doppler Contrast Echocardiography: Preliminary Experimental Results

This preliminary experimental study demonstrates the potential usefulness of harmonic power Doppler imaging in producing left ventricular myocardial opacification and demonstrating intra-myocardial coronary vessels during contrast echocardiography using Levovist, a saccharide-based contrast agent. The contrast effect was most dramatic when a vasodilator such as dipyridamole or nitroglycerin was used in conjunction with contrast injections of Levovist. No significant myocardial opacification was noted with B-mode harmonic imaging alone.     

Head-to-head comparison of fundamental, tissue harmonic and contrast harmonic imaging with or without an air-filled contrast agent, levovist, for endocardial border delineation in patients with poor quality images.

Recent developments in tissue harmonic imaging and intravenous contrast agents have enhanced left ventricular endocardial border delineation (EBD). In a total of 48 patients with poor quality images, apical 4- and 2-chamber views were obtained with fundamental, tissue harmonic and contrast harmonic imaging with or without intravenous Levovist, an air-filled contrast agent. The left ventricle (LV) was divided into 12 segments, and the EBD of each segment was scored: (1) not visible, (2) barely visible, (3) well delineated. The EBD index (EBDI), defined as the sum of the endocardial scores divided by 12 was obtained for each patient. Of a total of 576 LV segments, 231 were scored as 1 by fundamental imaging and that number decreased to 125 segments by tissue harmonic imaging and 116 segments by fundamental imaging with Levovist. The number of segments scored as 1 decreased to 38 segments by tissue harmonic imaging with Levovist, and to 29 segments by contrast harmonic imaging with Levovist. The EBDI by fundamental imaging was 1.85+/-0.29, which improved significantly with the addition of Levovist (2.10+/-0.36, p<0.001) and was nearly identical to that by tissue harmonic imaging (2.15+/-0.32, p=NS). Tissue and contrast harmonic imaging with Levovist further enhanced the EBDI (2.43+/-0.26, 2.51+/-0.27, respectively). Levovist enhances EBD, even in the fundamental mode, to the level obtained with tissue harmonic imaging. Tissue harmonic and contrast harmonic imaging are the best modalities for enhancing EBD after Levovist injection.     

Improvement in Endocardial Border Delineation Using Tissue Harmonic Imaging

Background and Methods: For years, tissue has been assumed to be a linear medium in diagnostic ultrasound applications; thus, no backscattered signals in the second harmonic band are expected in harmonic imaging without the injection of a contrast agent. However, it has been shown that a useful tissue image is formed even without a contrast agent. The aim of this study was to evaluate whether this tissue harmonic image provided improved visualization of endocardial borders. Fifty-six adult patients with various heart diseases were investigated using conventional two-dimensional echocardiography and tissue harmonic imaging. In 30 of these patients, the left ventricular endocardial borders were well defined in the standard parasternal and apical views using conventional two-dimensional echocardiography. In the remaining 26 patients, delineation of endocardial borders was not possible in at least two segments. The equipment used was an ATL HDI-3000 diagnostic system equipped with harmonic imaging. Results: In all 56 patients, the myocardium and valves could be imaged with tissue harmonic imaging. Harmonic recordings were sharper and contained fewer clutter artifacts than conventional recordings. Most striking was the enhancement of left ventricular endocardial borders. In the 26 patients with incomplete delineation of left ventricular endocardial borders, wall motion could be evaluated in 290 of 312 (93%) segments with tissue harmonic imaging compared with only 168 of 312 (54%) segments with conventional echocardiography (P < 0.001). Conclusions: Tissue harmonic imaging improves image quality and can be used to enhance the definition of left ventricular endocardial borders. These findings can be explained by the nonlinear propagation of ultrasound within the tissue, which results in distortion of the transmitted signal and, thus, harmonic generation.     

Enhancement of Left Ventricular Cavity Opacification by Harmonic Imaging After Venous Injection of Albunex

Venous injection of Albunex does not consistently produce left ventricular (LV) cavity opacification during conventional echocardiography. We postulated that by increasing the signal-to-noise ratio, harmonic imaging will result in more successful LV cavity opacification and provide a better assessment of regional LV systolic function. Forty-two patients with poor baseline endocardial delineation were given 10 ml intravenous injections of Albunex during continuous fundamental and harmonic imaging. Change in segmental wall-thickening scores and the confidence levels for these scores were assessed for 3 observers with various levels of experience. Compared with fundamental imaging, harmonic imaging significantly improved the success of LV cavity opacification (83% vs 62%, p <0.05). The background-subtracted video intensity within the central two thirds of the LV cavity increased threefold (from 10 ± 15 to 31 ± 29, p <0.05) with harmonic imaging. The spatial extent of opacification increased from 40% of the LV cavity during fundamental imaging to 65% with harmonic imaging (p <0.001). The confidence level for assessing regional LV systolic function improved (p <0.05) after contrast administration, particularly when observer experience was limited. We conclude that in patients with poor endocardial definition, injection of intravenous Albunex should be combined with harmonic imaging to improve LV cavity opacification.

We assessed left ventricular (LV) cavity opacification produced by venous injection of Albunex during fundamental and harmonic imaging in 42 patients. Harmonic imaging significantly increased the success rate of LV cavity opacification, the background-subtracted peak video intensity, and the spatial extent of cavity opacification; harmonic imaging also improved the confidence level for assessing regional LV systolic function, especially in readers with less experience.     

The clinical applications of contrast echocardiography.

Ultrasound contrast agents are approved for opacification of the heart chambers and to improve endocardial border definition. The myocardial contrast enhancement is also very useful for assessing thickening of the myocardium and myocardial perfusion. Several multicentre and numerous single-centre trials have demonstrated the usefulness of contrast echocardiography in clinical practice. Contrast echocardiography is probably one of the best validated echocardiographic techniques. Improved accuracy of contrast-enhanced images is not restricted to patients with a poor baseline image quality. Even with an optimal baseline image quality the borders are not as well defined as after LV opacification. Usage of contrast can improve image alignment and helps to avoid off-axis scanning. Contrast studies are particularly useful when a precise measurement of LV function is needed: 1. To decide about the need of implantable cardioverter-defibrillators (ICDs), cardiac resynchronization therapy (CRT), 2. Follow-up of patients with moderate valvular disease and decision for surgical treatment, 3. Selection and monitoring of patients undergoing chemotherapy with cardiotoxic drugs, 4. Assessment of LV function in patients in intensive care and coronary care units. Optimal endocardial border delineation is crucial and often can be achieved only by ultrasound contrast: 1. Assessment of LV thrombi and masses, 2. Left ventricular non-compaction/apical hypertrophy, 3. Right ventricular dysplasia, right ventricular thrombus, 4. Stress echocardiography and regional wall motion assessment. Future echocardiography will be more 3D and more quantitative than current echocardiography. And contrast echocardiography has already proven its value for both applications.     

Harmonic imaging: echocardiographic enhanced contrast intensity and duration

The intensity and duration of contrast effect within the left ventricular cavity after an intravenous bolus of Levovist Injection were observed with both harmonic and fundamental imaging in nine patients with known or suspected coronary artery disease. Contrast intensity was assessed by a qualitative grading system (0, none; 1, weak; 2, moderate; 3, good) and by videodensitometric analysis of pixel intensity. Duration of left ventricular contrast effect was determined by measuring time from the initial visual appearance of contrast agent to its disappearance. The mean increase in pixel intensity within the left ventricular cavity from precontrast to peak contrast was significantly greater for second harmonic than for fundamental imaging (25.5 vs 7.1; P < 0.012). The mean contrast intensity qualitative score with harmonic imaging was higher (2.6 ± 0.73 vs 1.2 ± 0.44; P < 0.01) and the duration of contrast effect was longer (242 ± 131 s vs 53 ± 33 s; P < 0.004). Second harmonic imaging significantly enhanced contrast intensity and prolonged visible duration of contrast effect after a peripheral venous injection of Levovist.     

Comparison of native and contrast-enhanced harmonic echocardiography for visualization of left ventricular endocardial border

Our study was designed to compare the utility of fundamental and second harmonic imaging (SH) for visualization of the left ventricular (LV) endocardial border. SH is a new imaging modality using nonlinear acoustic response, which may provide better endocardial border delineation. Standard apical views were studied in 42 patients using fundamental frequency (FF), SH without contrast (1.6- to 1.8-MHz and 2.1- to 2.5-MHz transmission frequencies), and SH after an intravenous injection of 2.5 g of Levovist. The quality of endocardial delineation in 16 standard segments was scored from 0 to 2. The endocardial visualization index was calculated as a mean of the scores. SH with and without contrast significantly improved LV endocardial border detection (endocardial visualization index 1.25+/-0.53, 1.64+/-0.67, 1.55+/-0.69, and 1.73+/-0.28 for fundamental, lower, and higher frequency harmonic and contrast-harmonic mode, respectively, p <0.005). Improvement was found in all LV segments. The number of invisible segments decreased from 142 (FF) to 54, 112, and 61 (in lower, higher, and contrast SH mode, respectively, p <0.001). Endocardial delineation in the apical segments using SH was optimal after contrast injection. In the basal LV area, contrast-enhanced images were less informative because of signal attenuation. Thus, SH significantly improves visualization of the LV endocardial border. Contrast enhancement with Levovist improves imaging of the apical segments but has no additional advantage in the basal segments. SH emerges as first-line modality for studies of LV function.     

Comparison of a new intravenous echo contrast agent (BY 963) with albunex for opacification of left ventricular cavity

Transpulmonary echo contrast agents improve the evaluation of left ventricular function by two-dimensional echocardiography due to a better endocardial border delineation. To compare the contrast effect in the right and left ventricular cavities, a new transpulmonary echocontrast agent, BY 963 and Albunex were intravenously administered to five non-anaesthetized dogs. The right and left ventricular echocardiographic image intensities were quantitatively measured at 60 cardiac cycles using a commercially available ultrasound system. BY 963 and Albunex were intravenously administered at three doses: 0.01 ml/Kg, 0.05 ml/Kg and 0.1 ml/Kg. The area under the curve (AUC, intensity units x heart cycles) and peak intensity (Peak I, intensity units) were estimated for the right (RV) and left ventricular (LV) cavities at the mid ventricular level using acoustic intensitometry. BY 963 injection produced the following values: At the dose of 0.01, 0.05 and 0.1 ml/Kg the AUC amounted to 702±449, 877±470 and 890±320 intensity units x heart cycles in RV and to 542±406, 806±557 and 721±392 in LV (LV/RV ratios: 77%, 92% and 81%). Peak I was at the doses 0.01, 0.05 and 0.1 ml/Kg 29±4.7, 33±5.2 and 35±3.2 intensity units in RV and 18±5.9, 21±6.2 and 20±3.3 in LV (LV/RV ratios: 62%, 64% and 57%).Albunex also produced right and left heart opacification values: at the doses 0.01, 0.05 and 0.1 ml/Kg the AUC amounted to 416±231, 493±231 and 674±390 in RV and to 71±71, 158±102 and 277±120 in LV (LV/RV ratios: 17%, 34% abd 41%). Peak I was at the doses of 0.01, 0.05 and 0.1 ml/Kg 19±5.2, 23±5.4 and 29±4.1 in RV and 8±4.8, 13±4.7 and 17±3.2 in LV (LV/RV ratios: 42%, 57% and 59%).Intravenous injection of BY 963 leads to complete opacification of the left ventricular cavity and to high AUC values and peak intensity values at all three dosages. The loss of contrast effect from the right to the left ventricular cavity was very low: the LV/RV ratio of BY 963 was higher than that of Albunex.The new transpulmonary echo contrast agent BY 963 promises to be an excellent echo contrast agent for the noninvasive assessment of left ventricular function.     

Intravenous contrast echocardiography

Intravenous contrast echocardiography has become possible in Japan because of the release of the commercially available contrast agent, Levovist. Intravenous administration of Levovist satisfactorily stains the left ventricular cavity, which makes it possible to clearly delineate the endocardial border. Clear delineation of the endocardial border provides easy and accurate measurement of left ventricular dimension and wall thickness, and wall motion abnormalities can be easily and accurately judged, too. Another benefit of intravenous contrast echocardiography is the assessment of myocardial perfusion. Our preliminary experimental and clinical experiences showed the possibility of myocardial staining with intravenous contrast echocardiography. Impressive myocardial staining is obtainable with the combined use of intermittent and contrast harmonic power Doppler imaging. In order to obtain reproducible and clear myocardial contrast images, we have to pay attention to how to inject contrast and settings of ultrasound equipment, i.e., mechanical index, gain setting, depth of focus point, and pulse repetition frequency, artifacts. In the near future, a lot of issues should be standardized to make it possible to compare myocardial contrast echo studies.     

Pulmonary transit of echocontrast agents during mechanical ventilation: a clinical transthoracic echocardiographic study

In this study, we investigated whether the ultrasound contrast agents Levovist or Sono Vue injected intravenously during mechanical ventilation effectively pass through the pulmonary circulation. With echocardiography, we measured the time for the contrast to pass through the lungs; and the intensity of right and left ventricular cavity opacification at four time points: during spontaneous breathing (baseline), 5 minutes after the beginning of mechanical ventilation, and 5 minutes and 30 minutes after extubation. Forty patients undergoing elective peripheral neurosurgical procedures were prospectively and randomly enrolled: 20 patients received intravenous Levovist 1 g and 20 patients received intravenous Sono Vue 1 mL, at the four predefined time points. After intravenous injection, both Levovist and Sono Vue effectively passed through the lungs and opacified the right and left ventricular cavities, at the four time points. Pulmonary transit times were similar and constant for the two contrast agents tested: 6 +/- 2 seconds at baseline, 5 +/- 2 seconds during mechanical ventilation, 7 +/- 2 seconds at 5 minutes and 6 +/- 2 seconds at 30 minutes after extubation with Levovist; and 6 +/- 4 seconds at baseline, 6 +/- 3 seconds during mechanical ventilation, 6 +/- 2 seconds at 5 minutes and 7 +/- 3 seconds at 30 minutes after extubation with Sono Vue. In all patients, each of the four contrast injections achieved high-grade right and left ventricular chamber opacification. In conclusion, both the ultrasound contrast agents tested in this study, Levovist and Sono Vue, after intravenous injection pass through the pulmonary circulation during mechanical ventilation. Ultrasound contrast agents with these characteristics are suitable for intraoperative organ perfusion studies, with intravenous injection.     

Use of harmonic echocardiographic contrast imaging and intravenous bolus of Levovist for evaluation of the left ventricle

Harmonic imaging is a new imaging modality using nonlinear acoustic response, which is particularly sensitive for the particles of contrast agents. Our study was designed to compare the potential of harmonic echocardiographic imaging of the left ventricle using a contrast agent, Levovist to improve the detection of endocardium in patients with suboptimal image quality. 40 patients were studied using standard transthoracic apical views of the left ventricle patients using fundamental frequency and second harmonic frequency after and intravenous injection of 2.5 g Levovist. The quality of endocardial delineation in 16 standard segments was scored from 0 to 2. Endocardial visualization index was calculated as a mean of the scores to express overall diagnostic quality. Harmonic imaging with contrast significantly improved left ventricular endocardial border detection (endocardial visualization index at baseline 1.24 +/- 0.41, with contrast 1.63 +/- 0.38; p < 0.001). The improvement was qualitatively observed in all parts of the left ventricle: in apex (2.4 +/- 0.8), in the middle part (2.5 +/- 0.9) and slightly less in the basal part (2.1 +/- 1.1) as scored on a 0-3 scale. The number of invisible segments decreased from 124 (fundamental) to 50 in contrast harmonic mode. The persistence of the contrast enhancement, prolonged in harmonic as compared to fundamental imaging (284 +/- 136s vs 117 +/- 87s; p < 0.001) enabled convenient recording of all necessary views. Harmonic imaging after an intravenous injection of Levovist significantly improves the visualization of left ventricular endocardial border. Prolonged contrast effect after a single bolus enhances the pertinence of the method in clinical practice.     

Combined use of contrast-enhanced 2-dimensional and color Doppler echocardiography for improved left ventricular endocardial border delineation using Levovist, a new venous echocardiographic contrast agent

Transthoracic echocardiography often provides inadequate endocardial border visualization, particularly of the left ventricular apex. The aim of this study was to determine whether the transpulmonary echocardiographic contrast agent, Levovist, could improve endocardial visualization. Accordingly, 43 patients underwent 2-dimensional echocardiography before and after intravenous administration of Levovist. Definition of the left ventricular septal, apical and lateral borders was graded: 0 = no definition, 1 = partial definition, 2 = complete definition. Color Doppler was performed before and after contrast in 32/43 patients and similarly scored to determine any further benefit in apical border detection. There was significant (p %lt; 0.001) improvement of the average end-diastolic scores of the septal, apical and lateral regions (1.4 %plusmn; 0.5, 0.6 %plusmn; 0.7 and 0.9 %plusmn; 0.5 before and 1.8 %plusmn; 0.4, 1.4 %plusmn; 0.6 and 1.7 %plusmn; 0.5 after Levovist). The average end-systolic score was significantly different (p %lt; 0.001) from end-diastolic values in the apex only (0.3 %plusmn; 0.6 before and 0.8 %plusmn; 0.7 after Levovist). Average apical scores using color Doppler improved from 0.3 %plusmn; 0.6 and 0.1 %plusmn; 0.2 during end-diastole and end-systole to 1.7 %plusmn; 0.5 and 1.2 %plusmn; 0.6, respectively, after Levovist (p %lt; 0.001); the average end-diastolic contrast-enhanced color Doppler score was significantly higher than the corresponding grey scale score (p %lt; 0.001). We conclude that left ventricular endocardial border definition is significantly improved by Levovist. The use of contrast enhanced color Doppler can compensate for limited efficacy of this method in the apex.     

Measurement of left ventricular volumes and ejection fraction after intravenous contrast agent administration using standard echocardiographic equipment

The enhancement of endocardial border delineation using second harmonic imaging and contrast administration improves the measurement of ventricular volumes. In the majority of existing echocardiographic equipment, however, harmonic imaging is not yet available. The aim of this study was to assess the feasibility of the measurement of left ventricular volumes and ejection fraction after intravenous administration of the contrast agent Levovist using standard echocardiographic equipment and fundamental imaging modality. In 10 patients with good-quality two-dimensional echo imaging, 4 g (400 mg/mL concentration) of Levovist was injected intravenously. Hewlett-Packard Sonos 2000 ultrasound equipment without second harmonic imaging capability was used. To avoid the destruction of microbubbles, the echo machine was set to produce only one end-systolic and one end-diastolic frame in each cardiac cycle (dual triggering). Native and contrast imaging measurements of left ventricular volumes and ejection fractions calculated by modified Simpson's rule were compared in the fundamental mode. Intraobserver and interobserver variability values were assessed. End-diastolic volumes in native continuous and triggered mode and by contrast echo were 126 +/- 48, 121 +/- 46, and 130 +/- 50 mL, respectively (NS), whereas end-systolic volumes were 79 +/- 48, 76 +/- 45, and 79 +/- 46 mL, respectively (NS). Calculated ejection fraction using the three different imaging modalities were 0.41 +/- 0.16, 0.41 +/- 0.16, and 0.42 +/- 0.16 (NS). The intraobserver and interobserver reproducibility values were excellent in triggered mode. Standard echocardiographic equipment with fundamental imaging modality in the triggered mode is suitable for the measurement of left ventricular volumes after intravenous Levovist administration. In clinically difficult patients, contrast echocardiography in triggered mode may be applied even if echocardiographic equipment does not have harmonic imaging possibility.     

Estimation of vasodilator response by analysis of Doppler intensity kinetics with myocardial contrast echocardiography using an intravenous standardized bolus administration.

HYPOTHESIS: Myocardial perfusion can be analyzed by the first pass of Doppler intensity (DI) signals in the myocardium by myocardial contrast echocardiography with triggered power Doppler harmonic imaging (PDHI). METHODS AND RESULTS: DI versus time plots during 1:1 triggering was acquired during a mechanically standardized intravenous bolus application of Levovist (400 mg ml(-1); 3 ml min(-1)) at rest and during vasodilator stress with dipyridamole. Data were analyzed in 21 patients (pts) with normal coronary arteries and in 6 pts with left anterior descending artery (LAD) stenosis. Transthoracic distal LAD-flow velocities could be determined in 7 normal pts. At stress the DI wash-in rate and the DI plateau increased (3.14+/-0.3 versus 5.06+/-0.4 DI s(-1); 24.6+/-2.5 versus 30.8+/-1.8 DI, respectively). To analyze the effect of heart rate on the DI versus time plots investigations were performed in 7 additional controls at rest and during rapid pacing. Heart rates below 100 bpm did not disturb the DI kinetics at 1:1 triggering. CONCLUSIONS: Myocardial perfusion can be assessed by the analysis of the first pass DI kinetics using Levovist. The estimation of vasodilator response by PDHI seems to be an alternative to the determination of coronary flow reserve.     

Myocardial contrast echocardiography for assessment of myocardial perfusion at rest in a patient with left main coronary artery stenosis

The present case will focus on the potential of hypoperfusion detection with myocardial contrast echocardiography (MCE) using power Doppler harmonic imaging (PDHI). PDHI is normally performed in a triggered mode. Microbubbles were destroyed by the ultrasound energy in the myocardium, and myocardium has to be refilled with microbubbles within the time interval between the ultrasound pulses to obtain repetitive information about perfusion. Using the contrast agent Levovist, however, real-time PDHI also results in myocardial opacification presumably due to perfusion signals of the arteriolar microbubble passage. A 45-year-old woman with typical stress-induced angina was admitted to our department for cardiac catheterization. Prior to the angiography a conventional echocardiogram showed normal left ventricular function. Tissue Doppler, however, demonstrated postsystolic longitudinal shortening of the septal, anterior, and lateral wall regions. Myocardial contrast echocardiography with triggered PDHI showed complete opacification of the myocardium at rest. Using real-time PDHI with Levovist, the septum could not be opacified. The consecutive angiography documented a severe unprotected main coronary artery stenosis. After angioplasty and stent implantation, MCE measurements were repeated. Repetitive intravenous bolus injections of Optison during triggered PDHI showed no differences to the investigation prior to the angioplasty. Using real-time PDHI with Levovist, however, there was a marked difference in comparison to the pre-interventional analysis. A complete opacification of the apical septum was observed. The present case suggests that different MCE techniques can analyze different compartments of the myocardial vasculature in clinical practice. This methodological comparison between triggered and real-time PDHI shows obviously differences in the DI signal detection due to the different microbubble behavior. Clinicians should be aware of the potentials of MCE to improve noninvasive diagnostic procedures in patients with ischemic heart disease.     

Right Atrial and Ventricular Infarction

In order to compare the results of transesophageal echocardiography (TEE) in diagnosis of right atrial (RA) and right ventricular (RV) infarction with those of transthoracic echocardiography (TTE), 11 patients admitted to the coronary care unit with the diagnosis of posteroinferior left ventricular (LV) acute myocardial infarction (MI) and electrocardiographic suspicion of extension to RV were studied. In two of the 11 patients, RA infarction was identified on the basis of akinesis of the RA free wall, dilatation of the atrial cavity, spontaneous echo contrast, mural thrombosis, and poor atrial contribution to RV filling. In all 11 patients, RV infarction was determined by akinesis of one or more segmental regions, dilatation of the cavity in four patients, and tricuspid regurgitation in seven. Only six cases of RV infarction were diagnosed with TTE. The findings indicate that TEE provides additional information to TTE for determining RA and RV infarction during the early stages of MI.     

Noncompaction of the ventricular myocardium: report of two cases with bicuspid aortic valve demonstrating poor prognosis and with prominent right ventricular involvement

Noncompaction of the ventricular myocardium is a rare, unclassified cardiomyopathy due to an arrest of myocardial morphogenesis. The characteristic echocardiographic findings consist of multiple, prominent myocardial trabeculations and deep intertrabecular spaces communicating with the left ventricular (LV) cavity. The disease typically involves the LV myocardium, but right ventricular (RV) involvement is not uncommon. The clinical manifestations include heart failure (HF) signs, ventricular arrhythmias and cardioembolic events. Noncompacted myocardium may occur as an isolated cardiac lesion, as well as it can be in association with congenital anomalies. We describe two illustrative cases of noncompaction of the ventricular myocardium, a 19-year-old male with bicuspid aortic valve and progressive worsening of HF, and a 61-year-old male with marked RV involvement in addition to LV apical involvement, both with the typical clinical and echocardiographic features of the disease.