Extent Of Wall Motion Abnormalities Research Articles

Impact of Total Ischemic Time on the Recovery of Regional Wall Motion Abnormality after STEMI in the Modern Reperfusion Era.

Background Total ischemic time (TIT) is an important factor for predicting mortality among patients with ST-segment elevation myocardial infarction (STEMI). However, the correlation between TIT and the extent of wall motion abnormality has not been well studied. Therefore, we investigated changes in the wall motion score index (WMSI) value based on TIT in STEMI patients who underwent primary percutaneous coronary intervention (PCI) and subsequent transthoracic echocardiography. Methods STEMI patients who underwent primary PCI and follow-up coronary angiography were analyzed after the exclusion of cases of in-stent restenosis (ISR). WMSI values were calculated by dividing the sum of scores by the number of segments visualized. Results A total of 189 patients underwent primary PCI for STEMI, and 151 had no ISR with a median follow-up of 12.3 months. TIT was 180 (117–369) minutes in a subset of 151 patients (mean age of 62 years; 76% male). Among patients without ISR, 109 (72%) demonstrated a decrease in the WMSI value during the follow-up period. The WMSI values of patients with TITs of 180 minutes or less were significantly decreased relative to those among patients with TITs of greater than 180 minutes (p=0.020). Among patients with TITs of 180 minutes or less, the TIT was significantly shorter among those with a reduction in the WMSI value than among those with an increase in the WMSI value (106 [81–124] vs. 133 [100–151] minutes; p=0.018). TIT was an independent predictor for a reduction in the WMSI value among these patients (adjusted hazard ratio: 0.976 (0.957–0.995); p=0.016). Conclusions In the modern reperfusion era of STEMI, patients with TITs of 180 minutes or less experienced a significant degree of recovery from regional wall motion abnormalities.

Myocardial deformation measures by cardiac magnetic resonance tissue tracking in myocarditis: Relationship with systolic function and myocardial damage

Introduction and ObjectivesCardiac magnetic resonance (CMR)-based tissue tracking (TT) enables quantification of myocardial deformation and may be used as an objective measure of myocardial involvement in myocarditis. The aims of this study were to characterize myocardial deformation alterations in myocarditis and to determine their relationship with the extent of late gadolinium enhancement (LGE), regional wall motion abnormalities (WMA) and left ventricular ejection fraction (LVEF). MethodsA single-center, retrospective study was conducted by identifying patients with clinically suspected myocarditis who underwent CMR between 2012 and 2016. The myocardial deformation parameters were derived by TT and correlated with LVEF, LGE and WMA, through Spearman's coefficient. ResultsA cohort of 78 patients with myocarditis (aged 42.7±17.2 years) were included. CMR characteristics including morphologic parameters (LVEF 52.1±12.8%), extent of WMA (29.3±41.0%) and of LGE (30.5±21.8%) were assessed. Significant correlations were found between all deformation parameters (strain, strain rate, velocity and displacement) and both LVEF and extent of WMA. LGE was significantly correlated with systolic radial strain (r: -0.32, p=0.004), strain rate (r: -0.27, p=0.017) and displacement (r: -0.32, p=0.004) as well as systolic circumferential strain (r: 0.28, p=0.013). ConclusionDeformation parameters are an objective method for quantification of myocardial function in myocarditis. They correlate with LVEF, extent of WMA and degree of myocardial damage. Further studies are needed to assess their incremental beneficial value for the diagnosis and risk stratification of myocarditis.

The Assessment of left ventricular Function in MRI using the detection of myocardial borders and optical flow approaches: A Review

The evaluation of left ventricular wall motion in Magnetic Resonance Imaging (MRI) clinical practice is based on a visual assessment of cine-MRI sequences. In fact, clinical interpreters (radiologists) proceed with a global visual evaluation of multiple cine-MRI sequences acquired in the three standard views. In addition, some functional parameters are quantified following a manual or a semi-automatic contouring of the myocardial borders. Although these parameters give information about the functional state of the left ventricle, they are not able to provide the location and the extent of wall motion abnormalities, which are associated with many cardiovascular diseases. In the past years, several approaches were developed to overcome the limitations of the classical evaluation techniques of left ventricular function. The aim of this article is to present an overview of the different methods and to summarize the relevant techniques based on myocardial contour detection and optical flow for regional assessment of left ventricular abnormalities.

The value of core lab stress echocardiography interpretations: observations from the ISCHEMIA Trial.

BackgroundStress echocardiography (SE) is dependent on subjective interpretations. As a prelude to the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) Trial, potential sites were required to submit two SE, one with moderate or severe left ventricular (LV) myocardial ischemia and one with mild ischemia. We evaluated the concordance of site and core lab interpretations.MethodsEighty-one SE were submitted from 41 international sites. Ischemia was classified by the number of new or worsening segmental LV wall motion abnormalities (WMA): none, mild (1 or 2) or moderate or severe (3 or more) by the sites and the core lab.ResultsCore lab classified 6 SE as no ischemia, 35 mild and 40 moderate or greater. There was agreement between the site and core in 66 of 81 total cases (81 %, weighted kappa coefficient [K] =0.635). Agreement was similar for SE type - 24 of 30 exercise (80 %, K = 0.571) vs. 41 of 49 pharmacologic (84 %, K = 0.685). The agreement between poor or fair image quality (27 of 36 cases, 75 %, K = 0.492) was not as good as for the good or excellent image quality cases (39 of 45 cases, 87 %, K = 0.755). Differences in concordance were noted for degree of ischemia with the majority of discordant interpretations (87 %) occurring in patients with no or mild LV myocardial ischemia.ConclusionsWhile site SE interpretations are largely concordant with core lab interpretations, this appears dependent on image quality and the extent of WMA. Thus core lab interpretations remain important in clinical trials where consistency of interpretation across a range of cases is critical.Trial registrationClinicalTrials.gov NCT01471522

The oldest patient with takotsubo cardiomyopathy.

Takotsubo cardiomyopathy (TTC) is a rare condition that affects mainly aging women. According to a retrospective review, patients with TTC accounted for approximately 2% of all the patients with suspected acute coronary syndrome (ACS). A few reports indicated that the average age of TTC patients was 68 years, although children or young adults may also be affected. In US and Europe, a number of contemporary TTC studies report that 90% of patients with TTC are women aged 65–70 years. Meta analysis showed that the age ranged from 10 to 89 years. [1] There was also one case study of a 90-year-old patient with TTC ― the oldest patient known so far. In that case, the patient died during the course of treatment from severe multi-organ failure. [2] In the present case report, we present a 98-years old woman with TTC admitted to our clinic. A 98-years old patient was admitted to our clinic because of significant chest pain and general weakness accompanied by hypotension that required catecholamine administration with ST-segment elevation in the anterolateral leads in ECG. The patient suffered from hypertension and third stage of chronic kidney disease. Urgent cardiac catheterization and ventriculography confirmed the absence of any critical coronary disease, but also the presence of a typical apical ballooning and midventricular hypokinesis. Troponin I (TnI) at admission was 5.555 ng/mL and creatine kinase soenzyme MB (CK-MB) mass was 14.5 ng/mL. Inflammatory parameters were not elevated, whereas N-terminal pro brain natriuretic peptide (NT-proBNP) concentration was markedly elevated, at 18,623 pg/mL. NT-proBNP/TnI ratio was 3352.48 on the first day and even higher after 24 h, at 7113.36. This markers profile is characteristic of TTC. There is a relatively small increase in creatine kinase and troponin concentrations in relation to the extent of wall motion abnormalities. BNP is always elevated in patients with TTC and is higher than in patients with ST-segment elevation myocardial infarction. Some researchers suggest that TTC can be distinguished from ACS on the basis of the characteristic profile of cardiac markers consisting of a sudden increase in the concentration of NT-proBNP in the first few days when there is only a small increase in markers of myocardial necrosis (the ratio of NT-pro BNP/troponin). [3]

Comparison of segmental wall motion abnormalities on echocardiography in patients with anteroseptal versus extensive anterior wall ST-segment elevation myocardial infarction

ObjectiveAcute anteroseptal ST-segment elevation (STE) myocardial infarction (AS-STEMI), defined as STE limited to leads V1 to V3, has historically been associated with a smaller infarct size than extensive anterior STEMI (EA-STEMI), in which STE extends to leads V4 to V6. We compared the differences in global and regional wall motion by transthoracic echocardiography between patients with AS-STEMI and EA-STEMI. MethodsPatients who presented with anterior STEMI and underwent primary percutaneous coronary intervention between January 2008 and March 2011 were included. For each subject, a transthoracic echocardiogram that was performed within 24hours of admission was interpreted by an independent investigator blinded to the patient's electrocardiographic data. ResultsOf the 65 subjects who met our inclusion criteria, 30 had AS-STEMI and 35 had EA-STEMI. No differences were observed between groups in baseline characteristics or the mean number of hypokinetic, akinetic, and dyskinetic segments. Apical inferior segment dysfunction occurred more often in patients with EA-STEMI than in patients with AS-ASTEMI (71.4% vs 43.3%; P=.04). Distribution and extent of wall motion abnormalities were similar between patients with AS-STEMI and those with EA-STEMI. ConclusionThe term AS-STEMI may be misleading, as it implies that only the anteroseptal segments are involved. We show that regional dysfunction in patients with AS-STEMI extends beyond the anteroseptal region.

Extent of wall motion abnormalities with cardiovascular magnetic resonance imaging overestimates the degree of coronary artery disease in patients with ischemic cardiomyopathy

Background Patients with ischemic cardiomyopathy (CMP) often develop regional wall motion abnormalities (WMA) due to myocardial scarring, stunning or hibernation. Abnormal functioning myocardial segments without evidence of fibrosis on late gadolinium-enhancement cardiac magnetic resonance (LGE-CMR) are felt to represent stunned or hibernating myocardium, presumably with significant coronary artery disease (CAD) in the vessel supplying the region. We analyzed the association between segmental wall motion abnormalities (WMA) and underlying CAD in ischemic CMP. Methods 53 consecutive patients referred for LGE-CMR with recent coronary angiography ( 50% transmural LGE, consistent with larger extent of WMA compared to LGE. No significant correlations were found between segments with any WMA and >50% transmural LGE (r= 0.05, p=0.71.). Of the 53 patients with ischemic CMP by LGE-CMR, 47 patients (89%) had documented coronary artery disease by angiography. There was no significant correlation between number of vessels with severe stenoses (>70%) and any WMA (r=0.19, p=0.18). Additionally, the number of segments with evidence of any WMA was more extensive than number of segments supplied by severe stenoses. Conclusions

Clinical Characteristics and Outcome of Left Ventricular Ballooning Syndrome in a European Population

We assessed the clinical characteristics and determinants of the prognosis of patients with left ventricular ballooning syndrome (LVBS) in an European population. A total of 128 patients with LVBS (98% women, age 67 ± 11 years) were prospectively followed up for a median of 13 months. A trigger event was identifiable in 58% of the patients. Anterior ST-segment elevation was documented in 38% and negative T waves in 41% of the patients. Apical ballooning was present in 82% and midventricular ballooning in 18%. The initial LV ejection fraction was 41 ± 9%. In-hospital events included the death of 1 patient (0.8%), LV failure in 13 (10%), LV thrombi in 4 (3.1%), sustained ventricular or supraventricular tachyarrhythmias in 6 (4.7%) and asystole in 2 patients (1.6%). The extent of wall motion abnormalities (odds ratio 4.16, p = 0.012), dyspnea at presentation (odds ratio 3.42, p = 0.01), and treatment with nitrates (odds ratio 0.30, p = 0.015) were significant univariate predictors of in-hospital events. The recovery of regional wall motion abnormalities occurred within 1 month of the event in 73% of patients. During follow-up, events occurred in 7 (6%) of 121 patients, including noncardiac death in 1 (0.8%), recurrent LVBS in 2 (1.6%), heart failure in 1 (0.8%), and recurrent chest pain in 3 (2.5%). In conclusion, in a European population, LVBS was characterized by a significant rate of in-hospital events, mainly related to pump failure, and low short-term mortality. The extent of wall motion abnormalities was the best predictor of acute events. Contractile recovery occurred within 1 month in most patients. The long-term prognosis was good, with a recurrence rate of <2%/year.

Real-Time 3-Dimensional Echocardiography

One of the most significant developments of the last decade in ultrasound imaging of the heart was the evolution of 3-dimensional (3D) imaging from slow and labor-intense offline reconstruction to real-time volumetric imaging. This imaging modality provides valuable clinical information that empowers echocardiographers with new levels of confidence in the diagnosis of heart disease. We have previously described the technological milestones in the development of real-time 3D echocardiographic (RT3DE) imaging and its major advantages over conventional 2-dimensional echocardiography (2DE) and reviewed the published literature that supported the use of this new methodology in clinical practice.1 Since 2006, the growing availability of RT3DE technology, its ease of use, and its multiple attractive features have sparked significant interest in the research community, resulting in a large number of publications, most of which have endorsed RT3DE imaging for clinical use by demonstrating its unique capabilities in different scenarios. In parallel, the clinical acceptance of this new tool has broadened significantly. The most recent clinically significant addition is matrix-array transesophageal echocardiography (TEE), which provides images of unprecedented quality that aid surgeons and interventional cardiologists in planning and guiding procedures and evaluating their outcomes. The purpose of the present article is to review the most recent RT3DE literature and provide readers with an update on the latest developments and the current status of this noninvasive imaging tool. Because different potential applications of RT3DE imaging have been explored to various extents, they are described here separately, and each is discussed with an emphasis on the scientifically established facts, along with the known stumbling blocks and difficulties. A firmly established advantage of 3D imaging over cross-sectional slices of the heart is the improvement in the accuracy of the evaluation of left ventricular (LV) volumes and ejection fraction (EF) by eliminating the need for geometric modeling, which …

The Extent of Microvascular Damage During Myocardial Contrast Echocardiography Is Superior to Other Known Indexes of Post-Infarct Reperfusion in Predicting Left Ventricular Remodeling: Results of the Multicenter AMICI Study

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. 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. 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. 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. 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.

Quantitation of Myocardial Borderzone Using Reconstructive 3-D Echocardiography After Chronic Infarction in Rats—Incremental Value of Low-Dose Dobutamine

Myocardial remodeling determines the degree of left ventricular dysfunction and mortality after transmural chronic myocardial infarction (CMI). Noninvasive characterization and quantitation of myocardial borderzone and collagenous scar are therefore parameters of clinical interest. The aims of this study were (i) to measure accuracy of reconstructive 3-D echocardiography (3DE) in scar and myocardial borderzone size assessment and (ii) to investigate the incremental value of low-dose dobutamine stress. 3DE was performed in 14 immunodeficient rats (rnu-rnu, 180–200 g) with anterior CMI 25 d after coronary ligation. Briefly, consecutive parallel short-axis cineloops were obtained electrocardiogram-gated starting from base to the apex. Morphology (mass, surface) and function (contractility, contractile reserve) of different compartments were assessed and correlated with 3-D histomorphometry. Histology was done using picrosirius red for collagen staining. 3DE left ventricular mass correlated closely with histomorphometry (y = 0.89x + 155, p < 0.0001, r = 0.80). Hypo- and akinetic myocardial surface correlated well with borderzone myocardium (y = 0.34x + 17, p = 0.009, r = 0.62) and collagenous scar (y = 1.9x + 4.4, p < 0.0001, r = 0.79), respectively. Extent of abnormal wall motion was closely related to borderzone and scar tissue area (y = 0.82x + 7, p < 0.0001, r = 0.77). 3DE quantitation of borderzone myocardium, but not collagenous scar, was more closely correlated to histomorphometry during inotropic stimulation. Global contractile reserve is positively associated with the size of myocardial borderzone. Regional contractile reserve of borderzone myocardium is not negatively associated with its collagen content. 3DE allows precise quantitation of myocardial borderzone and identification of transmural scar tissue noninvasively. Assessment of contractile reserve improves characterization and estimation of myocardial borderzone after CMI. (E-mail: ghanem@uni-bonn.de)

Location and Extent of Wall Motion Abnormality as Determinants of Systolic and Diastolic Remodeling

Location and Extent of Wall Motion Abnormality as Determinants of Systolic and Diastolic Remodeling

Does coronary angioplasty after timely thrombolysis improve microvascular perfusion and left ventricular function after acute myocardial infarction?

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. 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. 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. 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.

Apical ballooning syndrome without myocardial necrosis: Proof of concept from a case report

The “apical ballooning” is a cardiac syndrome characterized by acute extensive but reversible akinesia of the apex and mid part of the left ventricle (LV), without obstructive coronary artery disease (CAD), triggered by emotional or physical stress, accompanied by chest pain and/or dyspnoea, electrocardiographic changes mimicking acute coronary syndromes (ACS), and minimal but, to date, obligatory release of cardiac enzymes. Today the precise aetiology remains unknown, but prognosis is generally excellent. We hereby report a unique case of a 60-year-old woman presenting with transient wide anterolateral akinesia and severe LV dysfunction with persistently normal myocardial markers, despite the extent of wall motion abnormalities. This clinical vignette is the first proof of the concept that timely recognition and management may be able to prevent myocardial necrosis in patients with apical ballooning syndrome.

Infarct Size Assessment in Mice

Genetically modified mice are used extensively in models of ischemia reperfusion (I/R) and nonreperfused myocardial infarction (MI) to gain insights into pathways involved in these pathologies. Echocardiography is an ideal noninvasive tool to serially monitor the cardiac murine phenotype. The present review details the surgical aspects of I/R and MI models and the measurement of MI size by pathology techniques and the input of echocardiographic techniques including the extent of wall motion abnormality and of perfusion defects using myocardial contrast echocardiography in the assessment of murine area at risk and MI size.

Takotsubo Cardiomyopathy (Acute Left Ventricular Apical Ballooning Syndrome) Occurring in the Intensive Care Unit

Diagnosis of Takotsubo cardiomyopathy (also known as stress cardiomyopathy or acute left ventricular apical ballooning syndrome) can be challenging in patients who are being treated for other diseases in the intensive care unit, because symptoms could erroneously be attributed to the underlying disease or patients may not experience symptoms due to analgesia and sedation. The aim of our study was to assess clinical features of Takotsubo cardiomyopathy occurring in the intensive care unit. Prospective observational study. University hospital. Six consecutive patients diagnosed with Takotsubo cardiomyopathy who were being treated for other diseases in the intensive care unit. None. Sudden hemodynamic deterioration (i.e., sudden hypotension, tachycardia or drop in monitored stroke volume) requiring vasopressor support was the presenting symptom in five of the six patients. Only one patient was able to report angina-like chest pain, all others were unable to experience symptoms due to analgesia and sedation. The electrocardiogram was abnormal in all patients upon diagnosis, demonstrating either ST-segment elevation (n=2) and/or T-wave inversion (n=5). Mild elevation of cardiac enzymes disproportionate to the extent of wall motion abnormalities on left ventriculography was present in all patients. All patients survived their acute event. Sudden hemodynamic deterioration requiring vasopressor support and/or ECG abnormalities consisting of ST-segment elevation, ST-segment depression or T-wave inversion may be the presenting symptom of Takotsubo cardiomyopathy in the intensive care unit and should be included in the diagnostic algorithm.

The use of stress echocardiography for prognostication in coronary artery disease: an overview

Stress echocardiography has a high accuracy for the detection of coronary artery disease. Additionally, it provides clinically useful prognostic information, such as resting left ventricular function, myocardial viability, stress-induced ischemia, vascular extent of wall motion abnormalities, and changes in end-systolic volume and ejection fraction with stress. The timing, extent, and severity of the stress-induced wall motion abnormalities are important determinants of long-term prognosis. Previous studies have shown the efficacy of stress echocardiography in predicting long-term cardiac events in mixed patient groups and the value of this test in selected patient subsets. This review attempts to define the role of stress echocardiography for prognostication in coronary artery disease, pointing out the ability of this technique to identify low-risk and high-risk subsets among patients with known or suspected coronary artery disease and thus guide patient management decisions.

Hand‐held miniaturized cardiac ultrasound instruments for rapid and effective bedside diagnosis and patient screening

Technological progress in recent years has made it possible that ultrasound industry can now offer affordable, portable and battery-operated ultrasound systems the size of a laptop computer. The purpose of this study was to compare these hand-carried ultrasound instruments with standard echocardiography in order to investigate the facility of a rapid bedside diagnosis in patients with suspected or known cardiovascular disease. Fifty consecutive patients were studied with miniaturized ultrasound equipment (SonoHeart) and a conventional scanner (Acuson Sequoia) in a blinded manner. All studies were performed by three board-certified cardiologists skilled and experienced in echocardiographic practice. Investigators were not aware of any previous medical reports. With the new system, adequate images could be obtained in all patients. Left ventricular and left atrial diameters measured with the hand-held system correlated well with those obtained with conventional scanning: r = 0.87, mean difference 3.12 +/- 2.7 mm and r = 0.84, mean difference 2.8 + 2.4 mm, respectively. The presence of left ventricular dysfunction, regional wall motion abnormalities, relevant valvular regurgitation (moderate or more) or valve stenosis was correctly diagnosed in all patients. However, there was a tendency towards underestimating the extent of wall motion abnormalities particularly in patients difficult to image. Discrepancies also frequently occurred in patients with trivial or mild regurgitation, where false-positive and false-negative findings were described. Currently available hand-held echocardiography systems can facilitate rapid bedside diagnosis and patient screening. However, this recent development in echocardiography also raises a number of questions and its actual impact on general clinical practice still remains to be evaluated.

Relationship of systolic dysfunction to area at risk and infarction size after ischemia-reperfusion in mice

Whereas the extent of wall-motion abnormality (WMA) correlates well with the area at risk (AAR) and infarction size in murine models of nonreperfused myocardial infarction, this relationship is less clear in the setting of ischemia-reperfusion injury. Echocardiography was performed in mice at baseline, after left anterior descending coronary artery ligation (30 minutes) followed by reperfusion (24 hours), and after religation of the left anterior descending coronary artery. The extent of WMA before and after religation was compared with the initial infarction size measured by triphenyltetrazolium chloride and the AAR measured by fluorescent microspheres, respectively. Echocardiography showed left ventricular dilation and dysfunction after ischemia and reperfusion. WMA after religation correlated well with AAR ( r 2 = 0.70, P < .0001). The correlation between WMA and infarction size was incomplete ( r 2 = 0.59, P < .0002) in part because of underestimation of nontransmural infarcts. Echocardiography can reliably assess AAR after ischemia-reperfusion in mice; however, it does not allow for precise quantification of the small areas of necrosis that often occur in this setting.

Use of tissue Doppler imaging to facilitate the prediction of events in patients with abnormal left ventricular function by dobutamine echocardiography

The extent of abnormality in patients with positive dobutamine echocardiography (DE) is predictive of risk, but the wall motion score (WMS) has low concordance among observers. We sought whether quantifying the extent of abnormal wall motion using tissue Doppler (TD) could guide risk assessment in patients with abnormal DE in 576 patients with known or suspected coronary artery disease; standard DE was combined with color TD imaging at peak dose. WMS was assessed by an expert observer and studies were identified as abnormal in the presence of ≥1 segments with resting or stress-induced wall motion abnormalities. Patients with abnormal DE had peak systolic velocity measured in each segment. Tissue tracking was used to measure myocardial displacement. Follow-up for death or infarction was performed after 16 ± 12 months. Of 251 patients with abnormal DE, 22 patients died (20 from cardiac causes) and 7 had nonfatal myocardial infarctions. The average WMS in patients with events was 1.8 ± 0.5, compared with 1.7 ± 0.5 in patients without events (p = NS). The average systolic velocity in patients with events was 4.9 ± 1.7 cm/s and 6.4 ± 6.5 cm/s in the patients without events (p <0.001). The average tissue tracking in patients with events was 4.5 ± 1.5 mm and was significant (5.7 ± 3.1 mm) in those without events (p <0.001). Thus, TD is an alternative to WMS for quantifying the total extent of abnormal left ventricular function at DE, and appears to be superior for predicting adverse outcomes.