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Objectives: We sought to evaluate the value of the extent of microvascular damage as assessed with myocardial contrast echocardiography (MCE) in the prediction of left ventricular (LV) remodeling after ST-segment elevation myocardial infarction (STEMI) as compared with established clinical and angiographic parameters of reperfusion., Background: Early identification of post-percutaneous coronary intervention microvascular dysfunction may help in tailoring appropriate pharmacological interventions in high-risk patients. The ideal method to establish effective microvascular reperfusion after percutaneous coronary intervention remains to be determined., Methods: A total of 110 patients with first successfully reperfused STEMI were enrolled in the AMICI (Acute Myocardial Infarction Contrast Imaging) multicenter study. After reperfusion, peak creatine kinase, ST-segment reduction, and Thrombolysis In Myocardial Infarction (TIMI) and myocardial blush grade were calculated. We evaluated perfusion defects with MCE by using continuous infusion of Sonovue (Bracco, Milan, Italy) in real-time imaging. The endocardial length of contrast defect (CD) on day 1 after reperfusion was calculated. Wall motion score index, the extent of wall motion abnormalities, LV end-diastolic volume, and ejection fraction after reperfusion and at follow-up also were calculated., Results: Of 110 patients, 25% evolved in LV remodeling and 75% did not. Although peak creatine kinase, ST-segment reduction >70%, and myocardial blush grade were not different between groups, in patients exhibiting LV remodeling, TIMI flow grade 3 was less frequent (p < 0.001), wall motion score index was greater (p < 0.001), and CD was greater (p < 0.001). At multivariate analysis, only TIMI flow grade <3 and CD with a cutoff of >25% were independently associated with LV remodeling. Among patients with TIMI flow grade 3, CD was the only independent variable associated with LV remodeling., Conclusions: Among patients with TIMI flow grade 3, the extent of microvascular damage, detected and quantitated by MCE, is the most powerful independent predictor of LV remodeling after STEMI as compared with persistent ST-segment elevation and myocardial blush grade.

Objectives: The purpose of this study was to investigate whether a direct relation can be demonstrated between myocardial perfusion defects detected during dobutamine stress test (DST) by cardiovascular magnetic resonance (CMR) and impairment of coronary microvascular dilatory function in patients with cardiac syndrome X (CSX)., Background: Despite the fact that coronary microvascular dysfunction has been shown in most patients with CSX, the ischemic origin of CSX remains debated. No previous study assessed whether a strict relation exists between abnormalities in myocardial perfusion and coronary microvascular dysfunction in CSX patients., Methods: Eighteen CSX patients (mean age 58 +/- 7 years, 7 men) and 10 healthy control subjects (mean age 54 +/- 8 years, 4 men) underwent myocardial perfusion study by gadolinium-enhanced CMR at rest and at peak DST (maximal dose 40 microg/kg/min). Coronary flow response (CFR) to adenosine (140 microg/kg/min in 90 s) in the left anterior descending (LAD) coronary artery was assessed by high-resolution transthoracic echo-Doppler and expressed as the ratio between coronary flow velocity at peak adenosine and at rest., Results: At peak DST, reversible perfusion defects on CMR were found in 10 CSX patients (56%) but in none of the control subjects (p = 0.004). The CFR to adenosine in the LAD coronary artery was lower in CSX patients than in control subjects (2.03 +/- 0.63 vs. 3.29 +/- 1.0, p = 0.0004). The CSX patients with DST-induced myocardial perfusion defects in the LAD territory on CMR had a lower CFR to adenosine compared with those without perfusion defects in the LAD territory (1.69 +/- 0.5 vs. 2.31 +/- 0.6, p = 0.01). A significant correlation was found in CSX patients between CFR to adenosine and a DST perfusion defect score on CMR in the LAD territory (r = -0.45, p = 0.019)., Conclusions: Our data concurrently show DST-induced myocardial perfusion defects on CMR and reduced CFR in the LAD coronary artery territory in CSX patients, thus giving strong evidence that a dysfunction of coronary microcirculation resulting in myocardial perfusion abnormalities is present in these patients.

Intracoronary injection of bone marrow stem cells seems to improve left ventricular (LV) function after acute myocardial infarction (AMI). Granulocyte colony-stimulating factor (G-CSF) could improve myocardial function and perfusion noninvasively through mobilization of stem cells into peripheral blood, although previous clinical trials have produced controversial results. Forty-one patients with large anterior wall AMI at high risk of unfavorable remodeling were randomized 1:2 to G-CSF (10 microg/kg/day for 5 days) or to conventional therapy. All patients underwent successful primary or rescue percutaneous coronary intervention. LV function was assessed by echocardiography before G-CSF administration, > or =5 days after AMI, and at follow-up. Only patients with a LV ejection fraction <50% at baseline were enrolled in the study. After a median follow-up of 5 months (range 4 to 6) patients treated with G-CSF exhibited improvement in LV ejection fraction, from 40 +/- 6% to 45 +/- 6% (p = 0.068) in the absence of LV dilation (LV end-diastolic volume from 147 +/- 33 to 144 +/- 46 ml at follow-up, p = 0.77). In contrast, patients treated conventionally exhibited significant LV dilation (LV end-diastolic volume from 141 +/- 35 to 168 +/- 41 ml, p = 0.002) in the absence of change in LV ejection fraction (from 38 +/- 6% to 38 +/- 8%, p = 0.95). However, when comparing patients treated with G-CSF with controls, variations in these parameters were significantly different at 2-way analysis of variance (p = 0.04 for LV end-diastolic volume, p = 0.02 for LV ejection fraction). In conclusion, G-CSF prevents unfavorable LV remodeling and improves LV function in patients with large anterior wall AMI and decreased LV ejection fraction after successful percutaneous coronary intervention.

Background and Aim of the Study: Myocardial apoptosis has been implicated in heart failure and post-infarct remodeling. In some patients with severe aortic stenosis, delayed valvular replacement is associated with a poor in-hospital outcome. The study aim was to evaluate the impact of cardiomyocyte apoptosis on the postoperative course after aortic valve replacement (AVR) for severe aortic stenosis., Methods: During elective AVR, myocardial biopsies were obtained from the left ventricle of 11 patients with severe left ventricular hypertrophy (LVH), and the samples analyzed for apoptosis., Results: The mean apoptotic rate was 10.4 +/- 3.7 per thousand. (range: 5-16 per thousand). The apoptotic rate correlated directly with preoperative NYHA functional class, duration of intensive care unit (ICU) stay, number of days of postoperative acute renal insufficiency, and serum level of troponin T at 24 h; the apoptotic rate correlated inversely with cardiac index at 24 h postoperatively. At multivariate analysis, the apoptotic rate and left ventricular mass index were independent predictors of prolonged ICU stay. The apoptotic rate and duration of cardiopulmonary bypass were predictive of the duration of postoperative acute renal insufficiency., Conclusion: The study results showed an association between myocardial apoptosis and postoperative outcome in patients with severe LVH submitted for AVR. Non-invasive correlates of apoptosis may be introduced as a means of identifying patients at a higher operative risk, and may help in the evaluation of asymptomatic patients with severe aortic stenosis. Anti-apoptotic strategies before and during surgery would possibly ameliorate the surgical results.

Background: Recent data show that percutaneous coronary intervention (PCI) in patients with stable postthrombolytic ST-segment elevation myocardial infarction (STEMI) is better than no PCI or ischemia-guided PCI. These results still have to find a pathophysiologic explanation. We hypothesized that complete mechanical recanalization of infarct-related artery improves clinical benefits of thrombolysis as a result of more preserved and better perfused coronary microcirculation. To test this hypothesis, we studied a selected STEMI population presenting very early after symptom onset in whom successful infarct-related artery reperfusion was obtained by thrombolysis followed or not by elective PCI within 24 hours, and we compared these 2 groups with those underwent primary PCI., Methods: This study analyzed 96 patients with STEMI randomized within 3 hours from symptom onset to primary PCI (group A, n = 36), tenecteplase followed within 24 hours by PCI (group B, n = 30), or to tenecteplase alone (group C, n = 30). Microvascular perfusion was assessed by myocardial contrast echocardiography. Regional contrast score, endocardial length and area of contrast defect on day 2 (T1) and at predischarge (T2), left ventricular end-diastolic volume, regional wall motion score, extent of wall motion abnormalities, and ejection fraction at T1, T2, and at 3 months' follow-up were calculated., Results: Baseline clinical and angiographic characteristics were not statistically different between groups. The extent of microvascular damage and of myocardial salvage was similar in primary PCI-treated or in invasively treated patients after lytic administration. Conversely, group C patients, although treated very early with fibrinolytic therapy, showed higher extent of microvascular damage and infarct size and a more depressed left ventricular function after reperfusion and at follow-up., Conclusions: Our data suggest that early PCI after lysis is more effective in preserving myocardial perfusion and function than lysis alone and may be a helpful alternative when primary PCI is not available.

Data on coronary flow reserve (CFR) in patients with syndrome X are still controversial. Further, noninvasive evaluation of epicardial and microvascular flow reserves in these patients has never been performed. In 17 patients with syndrome X and in 17 age- and gender-matched control subjects, CFR in the mid left anterior descending coronary artery (LAD) was evaluated by transthoracic color and pulse-wave Doppler using a 7-mHz probe (Sequoia, Siemens). Peak diastolic LAD flow was calculated at rest and at peak adenosine (140 microg/kg/min intravenously in 90 seconds). Myocardial contrast echocardiography (MCE) was performed at rest and during adenosine use by real-time cadence pulse sequencing and intravenous SonoVue (Bracco; 5 ml at 1 ml/min) and microvascular blood volume (A), velocity (beta), and flow (Axbeta) by replenishing curves (y = A[1 - e(betat)]). CFR was measured by Doppler echocardiography as an adenosine/rest velocity ratio and by MCE as a microvascular volume, velocity, and flow adenosine/rest ratio. Compared with controls, patients with syndrome X demonstrated lower LAD CFR and velocity and flow microvascular flow reserves (p <0.01, <0.005, and <0.005, respectively). In patients with syndrome X, those with angina and ST-segment depression during adenosine testing had even lower LAD CFR and velocity and flow microvascular flow reserves compared with those with no symptoms (p <0.0001, <0.0001, and <0.005, respectively). LAD CFR demonstrated a significant linear correlation with velocity microvascular flow reserve (r = 0.92, p <0.0001) and flow microvascular flow reserve (r = 0.77, p <0.0001). In conclusion, CFR in the LAD, successfully evaluated by transthoracic Doppler echocardiography and MCE, is significantly decreased in patients with syndrome X and even more in those with angina pectoris and ST-segment depression during adenosine testing. Thus, noninvasive evaluation of CFR by echocardiography is feasible and provides information on the severity of microvascular impairment.

The burden of aortic stenosis is increasing steadily and, despite major advances in diagnosis and management, surgical valve replacement is still the only effective treatment. Most recently, experimental studies in animals and clinical studies in humans have shown that myocardial hypertrophy, microcirculatory dysfunction and cardiomyocyte apoptosis are among the central pathophysiologic mechanisms involved in the natural history of aortic stenosis, i.e. the passage from a compensated and hypertrophic heart to a dysfunctional heart prone to ischemia, arrhythmia and pump failure. This updated review emphasizes the promises of these new research avenues as well as their potential therapeutic applications.

Background: Information on the accuracy of both magnetic resonance imaging (MRI) and myocardial contrast echocardiography (MCE) for the identification of perfusion defects in patients with acute myocardial infarction is limited. We evaluated the accuracy of MRI and MCE, using Single Photon Emission Computed Tomography (SPECT) imaging as reference technique., Methods: Fourteen consecutive patients underwent MCE, MRI and 99mTc-MIBI SPECT after acute myocardial infarction to assess myocardial perfusion. MCE was performed by Harmonic Power Angio Mode, with end-systolic triggering 1:4, using i.v. injection of Levovist. First-pass and delayed enhancement MRI was obtained after i.v administration of Gadolinium-DTPA. At MCE, homogeneous perfusion was considered as normal and absent or "patchy" perfusion as abnormal. At MRI, homogenous contrast enhancement was defined as normal whereas hypoenhancement at first-pass followed by hyperenhancement or persisting hypoenhancement in delayed images was defined as abnormal., Results: At MCE 153 (68%) of segments were suitable for analysis compared to 220 (98%) segments at MRI (p<0.001). Sensitivity, specificity and accuracy of MCE for segmental perfusion defects in these 153 segments were 83, 73 and 77%, respectively. Sensitivity, specificity and accuracy of MRI were 63, 82, and 77%, respectively. MCE and MRI showed a moderate agreement with SPECT (k: 0.52 and 0.46, respectively). The agreement between MCE and MRI was better (k: 0.67) that the one of each technique with SPECT., Conclusion: MCE and MRI may be clinically useful in the assessment of perfusion defects in patients with acute myocardial infarction, even thought MCE imaging may be difficult to obtain in a considerable proportion of segments when the Intermittent Harmonic Angio Mode is used.

Objective: To test the hypothesis that impaired coronary and myocardial blood flow are linked with increased myocyte apoptosis, thus establishing a link between pressure overload and left ventricular (LV) remodelling., Methods and Results: Peak diastolic coronary blood flow velocity (CBFV) was evaluated at transthoracic Doppler echocardiography, and signal intensity (SI) and the rate of SI rise (beta) were measured at myocardial contrast echocardiography in 11 patients with severe aortic stenosis and LV hypertrophy. In the same patients, biopsies were obtained from the anterolateral LV free wall during surgery and analysed for cardiomyocyte apoptosis. LV mass corrected CBFV (CBFVI) was significantly lower in patients than in controls (median 0.100 cm.g/s (interquartile range 0.07-0.115) v 0.130 cm.g/s (0.130-0.160), p = 0.002). Similarly, SI*beta was significantly lower in patients than in controls (11 1/s (8-66) v 83 1/s (73-95), p = 0.001). Apoptotic rate was increased in aortic stenosis more than 100-fold versus controls (1.2% (0.8-1.4) v 0.01% (0.01-0.01), p < 0.001) and inversely correlated with lower CBFVI and SI*beta (r = -0.77, p = 0.001 for both)., Conclusions: Patients with severe aortic stenosis and LV hypertrophy have impaired myocardial perfusion, which is associated with enhanced cardiomyocyte apoptosis. Impaired myocardial perfusion and the ensuing oxygen demand-supply imbalance may, at least partially, be responsible for increased apoptosis and possible transition to heart failure, thus establishing a link between pressure overload, LV remodelling, and heart failure.

Previously defined as the failure to achieve uniform intramyocardial reperfusion after prolonged but reversible coronary occlusion, only recently has no-reflow phenomenon been characterized as a heterogeneous clinical condition. In fact, in about half of post-infarct patients that show no-reflow after 24 hours from coronary recanalization by either thrombolysis or PTCA, no-reflow phenomenon is spontaneously reversible. Reversible no-reflow is associated with favorable left ventricular remodeling even in the absence of significant improvement in regional contractile function. Thus, it may be a clinical marker of yet unknown mechanisms, which may favorably affect myocardial response to necrosis. Based on the pathogenesis and on the time-course of no-reflow, the phenomenon may be associated with lack of patency or with loss of anatomic integrity of microvessels, with the former being potentially reversible while the latter associated with definitive tissue damage. As a consequence, possible therapeutic strategies of no-reflow have to be designed according to not only the main target [microvessel patency or integrity], but also taking into account the timing of development of the damage. This "mini review" is focused on recent advances on the pathogenesis and clinical presentation on no-reflow. These data will give the opportunity to formulate novel interpretation and classification of the phenomenon and consequently, to propose adequate therapeutic strategies.

Aims: Recent data suggest that the administration of bone marrow-derived stem cells (BMSC) might improve myocardial perfusion and left ventricular (LV) function after acute myocardial infarction (AMI). The aim of this study was to assess spontaneous mobilization of BMSC expressing the haematopoietic and endothelial progenitor cell-associated antigen CD34+ after AMI and its relation to post-infarction remodelling., Methods and Results: Peripheral blood concentration of CD34+ BMSC was measured by flow cytometry in 54 patients with AMI, 26 patients with chronic stable angina (CSA), and 43 normal healthy subjects. In patients with AMI, LV function was measured by 2D-echocardiography. Eighteen AMI patients were reassessed at 1 year. BMSC concentration was higher in patients with AMI (mean peak value: 7.04+/-6.27 cells/microL), than in patients with CSA (3.80+/-2.12 cells/microL, P=0.036) and in healthy controls (1.87+/-1.52 cells/microL, P<0.001). At multivariable analysis statin use (P<0.001), primary percutaneous intervention (P=0.048) and anterior AMI (P=0.05) were the only independent predictors of increased BMSC mobilization after AMI. In the 28 patients without subsequent acute coronary events reassessed at 1 year follow-up, CD34+ cell concentration was an independent predictor of global and regional improvement of LV function (r=0.52, P=0.004 and r=-0.41, P=0.03, respectively)., Conclusion: AMI is followed by enhanced spontaneous mobilization of BMSC, in particular, in patients on statin therapy and following a primary percutaneous intervention. More importantly persistent spontaneous mobilization of BMSC might contribute to determine a more favourable post-AMI remodelling.

Objective: To identify in humans the temporal patterns of no reflow and their functional implications., Methods: 24 patients with first acute myocardial infarction and successful coronary recanalisation by recombinant tissue-type plasminogen activator (n = 15) or primary percutaneous transluminal coronary angioplasty (n = 9) were studied by myocardial contrast echocardiography within 24 hours of recanalisation and at one month's follow up. Myocardial contrast echocardiography was performed by intermittent harmonic power Doppler and intravenous Levovist. The regional contrast score index (CSI) was calculated within dysfunctioning myocardium. Videointensity was measured (dB) within risk and control areas and their ratio was calculated., Results: In 8 patients reflow was observed at 24 hours and persisted at one month. Conversely in 16 patients areas of no reflow were detectable at 24 hours. At one month, no reflow was spontaneously reversible in 9 patients (mean (SD) CSI and videointensity ratio improved from 2.5 (0.5) to 1.4 (0.6) and from 0.6 (0.1) to 0.7 (0.1), respectively; p < 0.05) and was sustained in the remaining 7 patients (CSI and videointensity ratio remained unchanged from 2.6 (0.6) to 2.6 (0.5) and from 0.5 (0.2) to 0.5 (0.2), respectively; NS). Left ventricular function improved significantly in patients with reflow and reversible no reflow. Volumes were enlarged only in patients with sustained no reflow., Conclusions: No reflow detected at 24 hours may be sustained or spontaneously reversible at one month. Such reversibility of the phenomenon is associated with preserved left ventricular volumes and function. Clarification of the mechanisms of delayed reversibility may lead to tailored treatment of no reflow even in the subacute phase of myocardial infarction.

Background: Myocardial contrast echocardiography (MCE) has potential value in the assessment and quantitation of myocardial perfusion defects. However, the severity of stenosis detectable by MCE and its diagnostic accuracy remain undefined. Thus, we produced coronary stenoses of variable severity and quantified their effect on MCE., Methods and Results: Three grades of left anterior descending (LAD) obstructions were produced in 7 open-chest swine. The stenoses were nonflow-limiting at rest, but decreased coronary hyperemia by 31.3% +/- 4.7%, 69.9% +/- 5.3% and 98.9% +/- 1.1%, respectively. Regional myocardial blood flow (RBF) was measured with fluorescent microspheres and was expressed as the ratio of LAD and control (LCx) beds. MCE was performed with 0.3 mg/kg intravenous AF0150 during ECG-gated harmonic imaging in short-axis view. Background-subtracted peak intensity (PI) was expressed as the ratio of LAD/LCx beds. Both RBF and PI ratios progressively decreased with increasing grades of stenosis. MCE showed a significant correlation with RBF (r = 0.74; P <.0001). Ratios of both PI and RBF differed significantly from baseline when coronary hyperemia was reduced more than 50%. An LAD/LCx ratio less than 0.6 by MCE yielded 61% and 83% sensitivity and 85% and 76% specificity with stenosis that reduced coronary hyperemia more than 50% and more than 75%, respectively., Conclusion: MCE with intravenous AF0150 during vasodilation correctly depicted the progressive reduction of flow ratios produced by graded coronary stenoses. A significant reduction of PI ratio was observed with stenosis causing more than 50% reduction of coronary hyperemia. An MCE ratio in stenosed/control beds could be selected, which exhibited good sensitivity and specificity in the identification of coronary stenosis.

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.

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.

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.

Background: Dynamic changes of myocardial blood flow have been observed after reperfusion of an occluded coronary artery. MCE performed by intracoronary contrast injection can provide an estimate of microvascular flow. We hypothesized that MCE performed using intravenous infusion of a new generation contrast agent and electrocardiogram-gated harmonic imaging would be able to assess serial changes of microvascular perfusion., Objective: To study the potential of myocardial contrast echocardiography (MCE) to assess serial changes of microvascular flow during ischemia-reperfusion., Methods: Sixteen dogs underwent 90 or 180 min of left anterior descending coronary occlusion, followed by 180 min of reperfusion. Regional blood flow (RBF) was measured with fluorescent microspheres at baseline, during coronary occlusion, and at 5, 30, 90, and 180 min during reperfusion. At the same time points, MCE was performed with intravenous infusion of AF0150 (4 mg/min). Gated end-systolic images in short axis were acquired in harmonic mode and digitized on-line. Background-subtracted videointensity measured from MCE and RBF obtained from fluorescent microspheres were calculated for the risk area and for a control area, and were expressed as the ratio of the two areas., Results: After initial hyperemia, a progressive reduction in flow was observed during reperfusion. MCE correctly detected the time course of changes in flow during occlusion-reperfusion. Videointensity ratio significantly correlated with RBF data (r=0.79; p < 0.0001)., Conclusions: The progressive reduction in blood flow occurring within the postischemic microcirculation was accurately detected by MCE. This approach has potential application in the evaluation and management of postischemic reperfusion in humans.

Background: Infective endocarditis remains a life-threatening disease, and its optimal management is of paramount importance. Transesophageal echocardiography (TEE) is useful for the diagnosis of endocarditis-induced lesions, but the prognostic significance of the method remains controversial., Hypothesis: The purpose of this study was to relate clinical and TEE characteristics to the occurrence of mortality and/or systemic embolization in a consecutive series of 45 patients with a diagnosis of infective endocarditis., Methods: All patients underwent at least one monoplane TEE. Clinical data, episodes of embolization, and echocardiographic characteristics were prospectively recorded. Stepwise logistic discriminant analysis was performed to identify the independent variables that best predicted three binary outcomes: systemic embolization, death, and systemic embolization and/or death., Results: Twelve of the 45 patients (27%) died from the endocarditis. Significant univariate predictors of death were the presence of paravalvular abscess (p = 0.025), number of vegetations (p = 0.021), Staphylococcus aureus isolated in blood cultures (p = 0.002), medical treatment alone (p < 0.002), and systemic embolism (p < 0.001). In multivariate analysis, systemic embolism (chi 2 = 29.3; p < 0.01), echocardiographic evidence of paravalvular abscess (chi 2 = 5.6; p = 0.018), Staphylococcus aureus endocarditis (chi 2 = 5.5; p = 0.016), and medical treatment alone (chi 2 = 5.11; p = 0.024) emerged as optimal predictors of death. Systemic embolization occurred in 12 patients. Independent variables predicting systemic embolization were a total length of vegetations > 14 mm (p = 0.01), greater age (p = 0.02), and medical treatment alone (p = 0.03). When two or more vegetations were observed, the total length is the sum of the individual sizes. Independent risk factors for the development of systemic emboli and/or death as a combined end point were total length of vegetations on TEE (chi 2 = 6.4; p = 0.003) and medical treatment alone (chi 2 = 4.1; p = 0.047)., Conclusions: High-risk patients may be identified by the combination of clinical variables and TEE characteristics.

Successfully reopening the infarct-related artery after acute myocardial infarction (MI) is currently achieved more frequently than before due to efficient therapeutic strategies, including new thrombolytic drugs and percutaneous transluminal coronary angioplasty. Successful reopening does not necessarily mean reperfusion; in fact the "no-reflow" phenomenon can occur. This phenomenon is due to functional and anatomic alterations, including microcirculation. Experimental and clinical studies have demonstrated that microvascular integrity is a fundamental prerequisite for ensuring viability after an acute MI. Often, studies have also shown that myocardial contrast echocardiography is a technique capable of detecting functional and anatomic conditions of microcirculation after ischemic reperfusion, and thus myocardial contrast echocardiography can be used for viability detection after acute MI.

Objective: To report a case of eosinophilic myocarditis with remarkable initial clinical manifestations and outcome., Material and Methods: A 67-year-old woman with hypertension and a history of asthma and drug hypersensitivity was referred to our institution with a diagnosis of acute myocardial infarction on the basis of severe chest pain, ST elevation on an electrocardiogram, and a slight increase in cardiac enzymes. Further diagnostic studies were performed., Results: Echocardiography disclosed left ventricular dysfunction in conjunction with apical asynergy, thinning, and thrombus. The eosinophil count in the peripheral blood was increased only slightly. Coronary angiography showed normal arteries and prompted the performance of endomyocardial biopsy, which revealed active eosinophilic myocarditis. After corticosteroid therapy, global and regional left ventricular function returned to normal., Conclusion: This unusual clinical picture and outcome demonstrate that eosinophilic myocarditis may simulate acute myocardial infarction and should be considered in patients with a history of allergies or acute left ventricular dysfunction, even in the absence of pronounced eosinophilia in the peripheral blood. With appropriate medical therapy, recovery for these patients can be complete.

Double-chambered right ventricle is an uncommon congenital heart disease, studied mostly by angiography, characterized by the division of the right ventricular cavity into two different pressure chambers. To analyze the anatomic features of this disease, data from 13 patients examined by echocardiography at the Mayo Clinic were reviewed. Despite the anatomic variety of this abnormality, two main types were identified. In the first type, intraventricular obstruction was due to an anomalous muscle bundle crossing the right ventricular cavity from the interventricular septum to the parietal wall. In the second type, no anomalous bundles were identified, and interventricular obstruction was due to marked parietal and septal hypertrophy. The main interventricular gradient was higher in the first type, and a ventricular septal defect was found to be associated more commonly with the second type.

Myocardial contrast echocardiography is a technique used in experimental and clinical settings in order to visualize the pattern of intramyocardial perfusion. In the acute phase of myocardial infarction, regional absence of flow during myocardial contrast echocardiography delineates the area at risk of necrosis, while the definitive non-perfused area expresses infarct size. Reopening the infarct-related artery, which may be achieved spontaneously by thrombolysis or percutaneous transluminal coronary angioplasty, is not a reliable indicator of intramyocardial reperfusion. If myocardial ischaemia due to coronary occlusion has been sufficiently prolonged and severe, not only myocyte viability, but also microvascular integrity is lost. Myocardial contrast echocardiography, using intracoronary injection of sonicated contrast medium, gives information about microvascular integrity and the effective presence of intramyocardial reflow. Anatomical integrity of microvasculature does not necessarily imply preserved function, and thus the microvessel vasodilating reserve may also be impaired. Myocardial contrast echocardiography has the potential to assess alterations in microvascular function, showing, in the myocardial area with reduced coronary reserve, a relatively reduced increase in echocontrast signal intensity when an intravenous vasodilator agent is administered.

Left ventricular recovery of dysfunctioning but viable myocardium can occur only in tissue in which both myocardial contractile reserve and microvascular integrity are preserved. Recent studies have demonstrated that both inotropic stimulating echo tests and myocardial contrast echocardiography can be used to assess myocardial viability in post-myocardial infarction patients. Therefore we performed a transesophageal and myocardial contrast echocardiographic evaluation of post-myocardial infarction patients to assess: the respective accuracy of post-extrasystolic potentiation and low-dose dobutamine (5 and 10 mcg) during transesophageal echocardiography in eliciting contractile reserve, and the potential of myocardial contrast echocardiography in predicting later functional recovery. Results of our studies showed comparable effects of low-dose dobutamine (5 mcg) and post-extrasystolic potentiation in increasing myocardial thickening while low-dose dobutamine (10 mcg) had a greater potential in eliciting residual contractility. Lastly, myocardial contrast echocardiography provided a clear spectrum of intramyocardial perfusion patterns in dysfunctioning areas but did not accurately correlate with later functional recovery as better predicted by low-dose dobutamine in the same segments. In conclusion, these methods represent the preferred choice of studying the perfusion-contraction match in viable myocardium thus playing an important role in prognostic and therapeutic strategies in myocardial infarction patients.

Infective endocarditis remains an important problem and the means of prevention are still insufficient. The causal bacteria have changed very little, but the incidence of nosocomial infections and endocarditis complicating intravenous drug abuse are increasing. The distinction between subacute and acute clinical presentations remains appropriate. Cardiac and neurological complications are frequent and carry a high risk of mortality. The diagnosis is obtained by the integration of clinical data and the results of blood cultures. Echocardiography is extremely useful for detecting vegetations, and for assessing the haemodynamic consequences and specific cardiac complications. Risk stratification can be obtained by correct integration of multiple parameters. The causal agent should be identified before the initiation of antimicrobial therapy. Surgery is frequently required, and should be performed rapidly when indicated.

In order to assess the role of multiplane transesophageal echocardiography in detecting mediastinal masses and in evaluating the manifestations of cardiac compression due to tumoral growth, 3 cases of patients with right ventricular outflow obstruction are presented. In each of these patients transesophageal echocardiography provided an accurate evaluation of the hemodynamic consequences of the tumoral process.