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Background Persistence of subtle abnormal myocardial deformation such as postsystolic shortening (PSS) after transient ischemia can be used to diagnose a history of myocardial ischemia (myocardial ischemic memory). Furthermore, early systolic lengthening (ESL) has recently attracted attention as another marker of myocardial ischemia. However, it is unclear whether the persistence of such abnormal deformation can be detected by three-dimensional (3D) speckle-tracking echocardiography, which has relatively low spatial and temporal resolution compared with two-dimensional echocardiography. The aim of this study was to evaluate the diagnostic accuracy of myocardial ischemic memory and its spatial extent using 3D speckle-tracking echocardiography. Methods The left circumflex coronary artery was occluded for 2 min, followed by reperfusion, in 33 dogs. Their hemodynamic and 3D echocardiographic data were chronologically acquired. Peak systolic strain, early systolic strain index as a parameter of ESL, postsystolic strain index as a parameter of PSS, and myocardial dysfunction index as a combined parameter of ESL and PSS were analyzed in all left ventricular segments. Results At the center of the risk area, early systolic strain index and postsystolic strain index significantly increased until 20 min after reperfusion compared with baseline, although peak systolic strain recovered by 20 min. Myocardial dysfunction index significantly increased for >20 min after reperfusion and allowed better diagnostic accuracy of ischemic memory than the other parameters. In the 147 risk segments, abnormal values of myocardial dysfunction index remained in 49 segments (33%) at 20 min after reperfusion, whereas abnormal peak systolic strain was observed in only 13 segments (9%). Conclusions ESL and PSS persisted after transient ischemia and could be detected by 3D speckle-tracking echocardiography. Integrated analysis of ESL and PSS provided higher diagnostic accuracy of ischemic memory. This method may be useful for detecting transient ischemic insults in patients after the disappearance of anginal attack.

Left atrial (LA) work can be measured through speckle tracking echocardiography by calculating LA pressure–strain loop area, which includes two distinct phases of active contraction/relaxation (A-work) and passive dilation/emptying (V-work). Echocardiographic and hemodynamic data were acquired at baseline and during occlusions of left anterior descending (LAD: n = 7) and left circumflex (LCx: n = 9) coronary arteries in dogs. Left ventricular (LV) circumferential strain was decreased and mean LA pressure was increased in both occlusions. Doppler-derived stroke volume was maintained during LAD occlusion, but it decreased during LCx occlusion. A-work increased during LAD occlusion, but it did not change during LCx occlusion. V-work decreased during LCx occlusion more than during LAD occlusion. The compensatory mechanism of LA function was limited during LCx occlusion, but this occurred during LAD occlusion. This study provided insight into a role of LA function in variable hemodynamic consequences in acute myocardial infarction.

Imaging technology capable of detecting myocardial ischemic memory is desired because angina is often temporary. Post-systolic shortening (PSS) is myocardial shortening after aortic valve closure, which is easily measured via speckle-tracking echocardiography and is a known sensitive marker of

Objective This study was established to examine the efficacy of a high-frequency liner probe for visualizing fine anatomy of coronary microcirculation. Methods The vessel size and its velocity-time integral at the anterior wall in dogs by real-time contrast echocardiography with high-frequency liner probe and pulse Doppler methods, and the coronary flow volume, were measured before and after adenosine triphosphate injection. A 3-dimensional (3D) image was reconstructed by the built-in 3D system using intermittent flash echocardiographic images. Results The increments of flow volume calculated from vessel sizes and velocity-time integral were well correlated with those of coronary flow volume. Using intermittent flash echocardiographic images, fine dots and lines of contrast echocardiographic–expected arterioles were evident, and easily and quickly reconstructed as coronary plexus by 3D system. Conclusion A high-frequency liner probe provides the fine-vessel images to evaluate those morphologic changes; a 3D reconstruction image could provide new information about coronary arterioles.

Background Residual collateral-derived myocardial blood flow (MBF) (A × β) is important to protect against myocardial ischemia after acute coronary occlusion. Methods Recruitment of microcollateral was assessed in 22 dogs with left circumflex coronary artery occlusion by analysis of MBF and regional wall thickening (WT) using real-time myocardial contrast echocardiography. Results Video intensity and WT at the center of risk area were significantly lower than those at the border of risk area. The video intensity, A value, β value, and MBF correlated well with WT after left circumflex coronary artery occlusion. The WT of the area with above 25% of normal MBF was preserved and was higher than that at below 25%. However, the deterioration of WT was not distinguished according to A value. Conclusion Real-time myocardial contrast echocardiography is a useful noninvasive method to evaluate collateral-derived MBF, which can be a reliable index of protection against myocardial ischemia.

Asanuma T, Fujihara T, Otani K, Miki A, Ishikura F, Beppu S. Noninvasive vessel-selective perfusion imaging with intravenous myocardial contrast echocardiography. J Am Soc Echocardiogr. 2004 Jun;17(6):654-8. doi: 10.1016/j.echo.2004.03.011., Background Intravenous myocardial contrast echocardiography (MCE) cannot identify each perfusion area of coronary vessels separately. However, by destroying microbubbles passing through a specific vessel using high-power ultrasound during intravenous MCE, vessel-selective perfusion imaging (VSPI) may be feasible. Methods In 10 open-chest dogs, intermittent short-axis images were obtained during contrast agent infusion using an ultrasound system. For VSPI, a probe coupled to another ultrasound machine was placed on the proximal left circumflex coronary artery (LCx). High-power ultrasound pulses were transmitted to destroy bubbles passing through the LCx. A negative contrast area on VSPI was considered to represent the perfusion area of the LCx (LCx-VSPI). A negative contrast area on conventional MCE during LCx occlusion and a region without staining by Evans blue dye were used as gold standards for defining the LCx perfusion area. LCx-VSPI was compared with a negative contrast area on conventional MCE during LCx occlusion and a region without staining by Evans blue dye. Results Despite lack of LCx occlusion, high-power destructive pulses produced a definite area of negative contrast on the LCx region. Decreased power of ultrasound pulses resulted in disappearance of the negative contrast area. An excellent relationship was demonstrated between both LCx-VSPI and a negative contrast area on conventional MCE during LCx occlusion (r = 0.93, P < .0001), and LCx-VSPI and a region without staining by Evans blue dye (r = 0.92, P = .0002). Conclusion: VSPI during intravenous MCE may be feasible for noninvasive assessment of perfusion areas associated with specific vessels.

The effect of ultrasound signal attenuation on myocardial blood flow parameters derived from contrast replenishment was evaluated using harmonic gray-scale (HGS) and harmonic power Doppler (HPD) imaging. In vitro experiments were performed in a flow model, whereas in vivo experiments were performed in 5 open-chest dogs. In each study, intermittent HGS and HPD images were acquired at various pulsing intervals during contrast infusion. A silicone pad was interposed between the transducer and target region to simulate attenuation conditions. Baseline-subtracted HGS and HPD signal intensities were measured with and without silicone pad, and myocardial blood flow parameters A and beta were calculated using contrast replenishment. Attenuation with HGS images could be offset by baseline subtraction, as baseline images provided the reference for attenuation. However, attenuation with HPD images could not be compensated for, as baseline signal intensity was theoretically 0. In HGS mode, silicone attenuation produced no significant decreases in A and beta. In HPD mode, however, A and beta were significantly decreased by silicone attenuation (A, P.001; beta, P.05). Compared with nonattenuated regions, myocardial blood flow parameters in attenuated regions are underestimated when HPD imaging is used. Baseline-subtracted HGS imaging may be useful to compensate for thoracic wall attenuation.

Our objective was to compare harmonic-to-fundamental frequency ratio peak (HFRp) analysis with conventional harmonic gray-scale densitometric analysis on the basis of ability to eliminate heterogeneity in ultrasound signals. Broadband radio frequency and harmonic data were obtained by using intermittent short-axis scans in 10 open-chest pigs before and during infusion of contrast microbubbles. HFRp and gray-scale intensity values were measured in 6 segments of left ventricular myocardium. In baseline images, the influence of anisotropy on HFRp values was significantly less than that in gray-scale intensities. In perfusion assessment with subtraction, contrast heterogeneity in HFRp values was significantly smaller than that in gray-scale intensities. The increase in HFRp values after subtraction was significantly greater than that in gray-scale intensities in lateral (P.001), posterior (P.0001), and inferior (P.01) myocardium. HFRp analysis can compensate for baseline myocardial anisotropy and regional contrast heterogeneity. With background subtraction, HFRp analysis allows better quantification of myocardial perfusion.

Although the distribution of atherosclerosis at the curved coronary segments has implications for atherogenesis and interventional procedures, few data exist regarding the plaque distribution in these sites. Therefore, we prospectively analyzed the intravascular ultrasound images of 55 coronary sites from 37 patients where the atherosclerotic plaque and pericardium were simultaneously demonstrated by intravascular ultrasound. The pericardial images were defined as a high-intensity linear echo image moving during cardiac cycles outside the vessel wall. By the line that was parallel to the pericardial image, the vessel area was divided into 2 semicircles with the same area, namely myocardial and pericardial sides. In each side, the maximal thickness, area, and percent area of plaque were measured. The plaque thickness and area of the myocardial side were significantly greater (1.5 ± 0.5 mm, 4.9 ± 2.1 mm2 or 66%, mean ± SD) than those of the pericardial side (1.1 ± 0.4 mm, 3.5 ± 2.1 mm2 or 45%, p

Background Recently, there have been many studies on genes or regenerations using small animals such as mice and rats. However, the therapeutic effects in genes or cell levels were not always available in organs. The effects on organs were evaluated by pathologic examinations. Ultrasound, a noninvasive examination, was used to evaluate organs of small animals. However, it was very difficult to evaluate in detail because of limited resolution. The evaluation of hearts in small animals is very difficult due to rapid heart rate and small size. Purpose We would like to introduce the availability of echocardiography to evaluate the cardiac function and myocardial perfusion in small animals. Methods Fourteen open-chest rats were examined to evaluate myocardial perfusion. Intravenous myocardial contrast echocardiography (MCE) was performed by fundamental and intermittent mode using a high-frequency transducer with SONOS 5500 during injection of NC 1001000. We compared the area at risk by MCE with that by Evans blue staining. Result All wall segments were clearly opacified and the risk area was clearly observed in the cases where the left anterior descending coronary artery was ligated. There was a good correlation between the area at risk by MCE and that by Evans blue staining. Conclusion Intravenous myocardial contrast echocardiography can detect perfusion defects, even in rats, using a high-frequency transducer.

Objectives. This study attempted to evaluate the effects of supine and lateral recumbent positions on pulmonary venous flow by transesophageal Doppler echocardiography in healthy subjects. Background. Although transesophageal echocardiographic examination is usually performed with the patient lying in the left lateral decubitus or supine position, little attention has been paid to the effects of these positions on pulmonary venous flow. Methods. We performed pulsed Doppler transesophageal echocardiography of the left and right pulmonary veins in 16 normal subjects as they lay in the left and right lateral decubitus and supine positions. Results. Data are reported as mean value ± SD. Adequate recordings were obtained in 12 subjects (75%). In the left pulmonary vein, peak systolic velocity and time-velocity integral of systolic flow increased significantly in the left compared with the right lateral decubitus position (56 ± 12 vs. 44 ± 13 cm/s, p < 0.05, and 15 ± 4 vs. 9 ± 4 cm, p < 0.05, respectively). In the right pulmonary vein, peak systolic velocity and time-velocity integral of systolic flow decreased significantly in the left compared with the right lateral decubitus position (38 ± 10 vs. 48 ± 9 cm/s, p < 0.05, and 9 ± 2 vs. 12 ± 2 cm, p < 0.05, respectively). There were no significant differences between positions in peak diastolic flow velocity, time-velocity integral of diastolic flow or peak velocity of flow reversal at atrial contraction. Conclusions. Pulmonary venous systolic peak velocities and time-velocity integrals of systolic flow Increase when the pulmonary venous recording is from the recumbent subject's lower side. Therefore, the effects of position should be considered in evaluating left ventricular diastolic function by transesophageal Doppler echocardiography.

In conclusion, left atrial appendage dysfunction may occur in VVI pacing with persistent retrograde ventriculoatrial conduction, and offers a potential explanation for an increased risk of thrombus formation.

We observed a patient who exhibited de novo left atrial thrombus formation after cardioversion, despite administration of adequate anticoagulant therapy. Preexisting atrial thrombus was excluded by transesophageal echocardiography. Preexisting severe left atrial mechanical dysfunction may be considered as a risk factor for de novo thrombus formation after cardioversion, as well as the poor outcome of cardioversion.

We report a case in which 2-dimensional echocardiography established the diagnosis of a left ventricular subepicardial aneurysm that was followed by rupture and sudden death before surgery. Two-dimensional echocardiography is of great help in detecting this rare complication after myocardial infarction. Urgent surgical treatment is warranted for this condition. (J Am Soc Echocardiogr 2000;13:951-2.)

lar damage in patrents with AMI. We investigated MCE with harmonic power Doppler (HPD), CFR and CF by using transthoracic echocardiography (TTE) in predicting func- tional recovery. Methods: We performed MCE (SONOSSSOO, Philips) by using 1:4 inter- mittent HPD with Levovist at rest and during ATP in 30 patients two weeks after anterior AMI. Peak videointenstty was measured within the risk and control regions. The peak intensity ratios of the risk area to the control area (PIR) at rest and during hyperemia were calculated. We measured CFR of the left anterior descending artery (LAD) two weeks after AMI. CF of LAD by TTE was also obtained within 24 hours after successfully recanalization