Echocardiographic quantification of regional left ventricular wall motion with color kinesis

Comparative Effectiveness and Harms of Intraoperative Transesophageal Echocardiography in Noncardiac Surgery: A Systematic Review

Intraoperative use of transesophageal echocardiography (TEE) has become commonplace in high-risk noncardiac surgeries but the balance of benefits and harms remains unclear. This systematic review investigated the comparative effectiveness and harms of intraoperative TEE in noncardiac surgery. We searched Ovid MEDLINE, PubMed, EMBASE, and the Cochrane Library from 1946 to March 2017. Two reviewers independently screened the literature for eligibility. Studies were assessed for the risk of selection bias, confounding, measurement bias, and reporting bias. Three comparative and 13 noncomparative studies were included. Intraoperative TEE was employed in a total of 1912 of 3837 patients. Studies had important design limitations. Data were not amenable to quantitative synthesis due to clinical and methodological diversity. Reported incidence of TEE complications ranged from 0% to 1.7% in patients undergoing various procedures (5 studies, 540 patients). No serious adverse events were observed for mixed surgeries (2 studies, 197 patients). Changes in surgical or medical management attributable to the use of TEE were noted in 17% to 81% of patients (7 studies, 558 patients). The only randomized trial of intraoperative TEE was grossly underpowered to detect meaningful differences in 30-day postoperative outcomes. There is lack of high-quality evidence of effectiveness and harms of intraoperative TEE in the management of non-cardiac surgeries. Evidence, however, indicates timely evaluation of cardiac function and structure, and hemodynamics. Future studies should be comparative evaluating confounder-adjusted impact on both intraoperative and 30-day postoperative clinical outcomes.

Utilization of Intraoperative Real-time Three-Dimensional Transoesophageal Echocardiography to Objectively Assess Improvement in Synchronization and Regional Wall Motion after Coronary Reperfusion

It is well known that myocardial ischemia leads to Regional Wall Motion Abnormalities (RWMAs) and reversible depression of Left Ventricular (LV) systolic function. Transoesophageal Echocardiography (TEE) is an established tool for early diagnosis of new RWMAs. However, evaluation of RWMAs by echocardiography is largely qualitative and relies on visual assessment of wall segments. Evaluation of LV systolic function and Ejection Fraction (EF) is more reproducible and accurate with Real-Time 3D Echocardiography (RT3DE) as compared with two-dimensional and M-mode techniques. Primary advantages for RT3DE are fast and largely automated volumetric analysis of LV function and LV volumes, without geometric assumptions and risk of underestimating volumes in foreshortened views. This case illustrates the use of intraoperative RT3DE during coronary artery bypass surgery to objectively assess: LV systolic function with LV volumes and RWMAs and improvement in cardiac synchronization following coronary reperfusion.

Role of echocardiography in the contemporary management of chronic heart failure

Echocardiography is an excellent noninvasive tool for the assessment of ventricular size and both systolic and diastolic function, and it is routinely used in patients with heart failure. This review will discuss the role of echocardiography in heart failure diagnosis, prognostic assessment and in the management of heart failure patients.

Evaluation of left ventricular diastolic function by fractional area change using cine cardiovascular magnetic resonance: a feasibility study

BACKGROUND

Evaluation of left ventricular (LV) diastolic function is essential for the management of heart failure. We verified whether LV diastolic function could be evaluated by measuring the fractional area change (FAC) using cine cardiovascular magnetic resonance (CMR).

METHODS

We collected clinical data from 59 patients who underwent echocardiography and cine CMR. Normal, impaired relaxation, pseudonormal, and restrictive LV filling were observed in 15, 28, 11, and 5 patients, respectively. We calculated FAC during the first 30% of diastole (diastolic-index%) in the short-axis view, by tracing the contours on only three MR cine images.

RESULTS

The diastolic index was significantly lower (p < 0.0001) in patients with impaired relaxation (32.4 ± 7.5), pseudonormal filling (25.4 ± 5.6), and restrictive filling (9.5 ± 1.5) compared to those with normal diastolic function (67.7 ± 10.8), and the index decreased significantly with worsening of diastolic dysfunction. The diastolic index correlated positively with early diastolic mitral annular velocity measured by tissue Doppler imaging (r = 0.75, p < 0.0001), respectively.

CONCLUSIONS

Measurement of FAC can be useful for the evaluation of LV diastolic function using cine CMR.

Semi-automatic algorithm for construction of the left ventricular area variation curve over a complete cardiac cycle

Background

Two-dimensional echocardiography (2D-echo) allows the evaluation of cardiac structures and their movements. A wide range of clinical diagnoses are based on the performance of the left ventricle. The evaluation of myocardial function is typically performed by manual segmentation of the ventricular cavity in a series of dynamic images. This process is laborious and operator dependent. The automatic segmentation of the left ventricle in 4-chamber long-axis images during diastole is troublesome, because of the opening of the mitral valve.

Methods

This work presents a method for segmentation of the left ventricle in dynamic 2D-echo 4-chamber long-axis images over the complete cardiac cycle. The proposed algorithm is based on classic image processing techniques, including time-averaging and wavelet-based denoising, edge enhancement filtering, morphological operations, homotopy modification, and watershed segmentation. The proposed method is semi-automatic, requiring a single user intervention for identification of the position of the mitral valve in the first temporal frame of the video sequence. Image segmentation is performed on a set of dynamic 2D-echo images collected from an examination covering two consecutive cardiac cycles.

Results

The proposed method is demonstrated and evaluated on twelve healthy volunteers. The results are quantitatively evaluated using four different metrics, in a comparison with contours manually segmented by a specialist, and with four alternative methods from the literature. The method's intra- and inter-operator variabilities are also evaluated.

Conclusions

The proposed method allows the automatic construction of the area variation curve of the left ventricle corresponding to a complete cardiac cycle. This may potentially be used for the identification of several clinical parameters, including the area variation fraction. This parameter could potentially be used for evaluating the global systolic function of the left ventricle.

Assessment of left ventricular diastolic function using color kinesis: differentiation between normal and pseudonormalized patterns

PURPOSE

Doppler examination of transmitral flow has been widely used to noninvasively assess left ventricular (LV) diastolic function. However, it has been demonstrated that transmitral flow velocity is dependent on LV relaxation and left atrial pressure. Increases in left atrial pressure compensate for the effects of impaired LV relaxation, frequently resulting in a "pseudonormalization" of the transmitral flow pattern. The purpose of this study was to assess whether analysis of diastolic color kinesis (CK) can be applied to differentiation between normal and pseudonormalized (PN) patterns of LV inflow.

METHODS

We studied 60 subjects with a ratio of early to late transmitral peak velocities (E/A) greater than 1.0 according to conventional Doppler echocardiography. All subjects simultaneously underwent measurement of the early diastolic mitral annular velocity (e'), which was measured by tissue Doppler imaging, and LV ejection fraction (EF), which was calculated by the modified Simpson method. Study subjects were classified into the following three groups according to the value of e' and EF: (1) the normal group (e' > 10 cm/s, EF > 60%), including 20 subjects (mean age 35 ± 10 years); (2) the PN1 group (e' < 7 cm/s, EF > 50%), consisting of 20 patients [mean age 63 ± 11 years, 15 patients with hypertensive heart disease (HHD), 5 patients with aortic valve stenosis]; and (3) the PN2 group (e' < 7 cm/s, EF < 50%), consisting of 20 patients (mean age 61 ± 17 years, 18 patients with dilated cardiomyopathy, 2 patients with HHD). Diastolic CK images were obtained for each subject from the LV midpapillary short-axis view. Analysis of CK diastolic images was performed using ICK software. The CK-diastolic index (CK-DI) was defined as the calculated LV segmental filling fraction during the first 30% of diastole, expressed as a percentage. The mean CK-DI was determined from the average CK-DI of six LV segments.

RESULTS

The mean CK-DI was 70.9% ± 6.5% in the normal group, 46.3% ± 10.4% in the PN1 group, and 36.3% ± 5.1% in the PN2 group. The mean CK-DI was significantly reduced in the PN1 and PN2 groups compared with the normal group (P < 0.0001). Although there was no difference in e' (PN1 group: 4.6 ± 1.8 cm/s, PN2 group: 4.4 ± 1.7 cm/s) between the two pseudonormalized patient groups, the mean CK-DI was significantly reduced in the PN2 group compared with the PN1 group (P < 0.005). The reduction in mean CK-DI was seen not only in pseudonormalized patients with LV systolic dysfunction but also in those with preserved LV systolic function.

CONCLUSION

The analysis of diastolic CK with ICK software is a useful method for detecting delayed early diastolic relaxation. We concluded that diastolic CK images may be applied to differentiating between normal and pseudonormalized patterns of LV inflow.

Diagnostic value of parametric imaging of left ventricular wall motion from contrast-enhanced echocardiograms in patients with poor acoustic windows

BACKGROUND

Analysis of left ventricular (LV) regional wall motion (RWM) is subjective and may be challenging in patients with suboptimal images, even with contrast enhancement. It was hypothesized that the amplitude and timing of RWM obtained from contrast-enhanced echocardiograms can be accurately represented in still-frame parametric images. This study was designed to (1) test this hypothesis, (2) establish the diagnostic value of these images as an aid for inexperienced readers, and (3) test the feasibility of automated quantitative analysis of RWM.

METHODS

Contrast-enhanced apical 4-chamber, 2-chamber, and 3-chamber LV views were acquired in 45 patients with poor acoustic windows. The interpretation of dynamic images by an experienced reader who classified RWM as normal or abnormal was used as a reference for comparisons against (1) visual interpretation of parametric images, (2) interpretation of dynamic images by two inexperienced readers (American Society of Echocardiography level I) without and subsequently with parametric images, and (3) automated quantification of RWM.

RESULTS

Expert readers detected abnormal RWM in 30 patients (437 of 945 segments). Visual interpretation of parametric images showed good agreement with the reference (sensitivity, 85%; specificity, 82%; accuracy, 84%). The interpretations by inexperienced readers improved with the addition of parametric images, with increases in specificity (from 58% to 79%) and accuracy (from 74% to 84%), despite a slight decrease in sensitivity (from 92% to 91%). Automated classification was feasible and accurate (sensitivity, 82%; specificity, 78%; accuracy, 80%).

CONCLUSION

Parametric images derived from contrast-enhanced echocardiograms of patients with poor acoustic windows accurately depicted RWM, improved the diagnostic accuracy of inexperienced readers, and allowed the objective detection of RWM abnormalities.

Detection of left ventricular systolic and diastolic abnormalities in patients with coronary artery disease by color kinesis

BACKGROUND

Color kinesis (CK) is a recently developed echocardiographic technique based on acoustic quantification that automatically tracks and displays endocardial motion in real time and has been used in initial studies to improve the evaluation of global and regional wall motion.

HYPOTHESIS

For further validation of the use of CK for analysis of segmental ventricular dysfunction, we assessed its sensitivity and specificity for detection of regional systolic and diastolic wall motion abnormalities in patients with coronary artery disease (CAD).

METHODS

Two-dimensional (2-D) echocardiography and CK were used to study 15 normal subjects and 63 patients with technically good quality echocardiographic tracings, who underwent coronary arteriography within 1 month of echocardiography. Significant (> 70% luminal diameter stenosis) CAD was present in 50 patients (79%).

RESULTS

Color kinesis tracked endocardial motion accurately in 93% of left ventricular segments. Wall motion score, systolic segmental endocardial motion (SEM), and the time of systolic SEM (tSEM) and diastolic (tDEM) segmental endocardial motion were calculated. Intra- and interobserver variability were within narrow limits. SEM and tSEM were significantly lower and tDEM was significantly higher in the patient population than in the control group (p < 0.001). Comparison between CK and 2-D echocardiography showed a correlation coefficient of 0.81 between the two techniques. The score was identically graded in 74% of segments, with concordance of 82% in diagnosing segments as abnormal. Interobserver concordance was 86% for CK (r = 0.85) and 81% for 2-D echocardiography (r = 0.80). The sensitivity and specificity of systolic and diastolic CK parameters for the detection of CAD were 88 and 92% and 77 and 85%, respectively. The positive predictive values were 93 and 96%, respectively, the negative predictive values were 63 and 73%, respectively, and the overall accuracy was 86 and 91%, respectively.

CONCLUSIONS

Our data suggest that CK is a feasible and sensitive technique for identifying regional systolic as well as diastolic wall motion abnormalities in patients with CAD.

Power motion imaging can improve image quality in stress conditions with tachycardia

BACKGROUND

Stress echocardiographic studies are useful, but the evaluation of wall motion is sometimes suboptimal. The recently developed technique of power motion imaging can enhance mobile tissue definition.

HYPOTHESIS

The study was undertaken to determine whether power motion imaging improves endocardial definition during tachycardia compared with conventional two-dimensional (2-D) imaging.

METHODS

Twenty pigs were studied during pacing rates of 100, 120, and 150 beats/min. We compared power motion imaging with standard 2-D imaging using systolic thickening visualization (STV) scores (3 = excellent definition of systolic thickening approximately 0 = total lack of visualization of systolic thickening) at each heart rate. We calculated the sum of the scores of 22 left ventricular segments as the overall STV score, and also calculated the sum of the scores in 10 parasternal segments and 12 apical segments separately.

RESULTS

The overall STV scores in both imaging methods were similar at 100 beats/min, but scores for power motion imaging were significantly higher than those of usual 2-D imaging at 120 and 150 beats/min. Using power motion imaging, the overall STV scores were similar as heart rate was increased; however, while using standard 2-D imaging, STV scores were significantly decreased as heart rate was increased. Findings were analyzed separately by parasternal and apical images. Especially in the parasternal images, the scores were significantly increased as heart rate was increased using power motion imaging.

CONCLUSIONS

We conclude that power motion imaging improves the detection of endocardial border in stress condition with tachycardia, and thus this modality is useful for stress echocardiography.

In vivo validation of a novel method for regional myocardial wall motion analysis based on echocardiographic tissue tracking

The objective of this study was to validate a recently developed tissue tracking (TT) method for cardiac motion, by comparing it with precise invasive measurements of motion and to prove its capability to reflect moderate hemodynamic changes induced by asynchronous activation. In four open-chest sheep, sono-crystals measured the left ventricle(LV) equator's diameters simultaneously with 2D ultrasound acquisition. The LV was paced either from the posterior or from the lateral wall, just prior to the normal LV activation. Global functional indices were calculated based on the regional motions extracted by the TT method. The correlation coefficient between the shortening of the diameters and the global circumferential strain (GCS) was 0.99 +/- 0.004. The peak GCS differentiated between the pacing modes (paired t test, P < 0.05). The GCS, a measurement closely based on the TT method, followed the precise sono-crystals measurements and reflected moderate hemodynamic changes, thus providing a substantial proof of the TT method's accuracy and clinical value.

Echocardiography and assessing fluid responsiveness: acoustic quantification again into the picture?

Accurate identification of fluid responsiveness has become an important issue in critically ill patients. Pulse pressure and stroke volume variation have been shown to be reliable predictors of fluid responsiveness. Apart from these two valuable techniques, echo-Doppler offers an interesting alternative for estimating the adequacy of filling. Acoustic quantification is a high-tech tool for delineating the blood-tissue interface on-screen in real time. Cannesson and coworkers utilized this technique in ventilated patients to assess stroke area changes, with the intention being to predict fluid responsiveness.

Usefulness of automated quantitation of regional left ventricular wall motion by a novel method of two-dimensional echocardiographic tracking

A novel 2-dimensional (2-D) echocardiographic tracking method enables the automated tracking of displacement between 2 points of interest in echocardiographic images. The purpose of this study was to evaluate whether this 2-D tracking method could be used to measure left ventricular (LV) wall thickness and percent systolic wall thickening (%WT) in parasternal short-axis views, in comparison with conventional manual measurement, and to determine whether this system can be used to quantitatively assess regional LV wall motion in echocardiography. In 24 subjects (12 with LV wall motion abnormalities), 6 segments in the short-axis images were assessed by this method. Two sample points at the endocardium and epicardium were tracked automatically during 1 cardiac cycle. Then, LV wall thickness and %WT were calculated. In 50 subjects (32 with LV wall motion abnormalities), average %WT as an average of all %WT in every degree of angle in each of the 6 segments was measured by this method, and the results were compared with the visual assessment of LV wall motion scores. There was excellent agreement between the 2-D tracking and manual methods for LV wall thickness (r = 0.99) and %WT (r = 0.97). The mean differences in LV wall thickness and %WT were 0.1 +/- 0.4 mm and 0 +/- 5.4%, respectively. Average %WT was significantly decreased in the regions of hypokinetic or akinetic wall motion compared with those of normal motion (18 +/- 4% and 4 +/- 4% vs 39 +/- 10%, p <0.001). In conclusion, this 2-D tracking method can be used for the noninvasive, automated quantitation of LV wall motion in 2-D echocardiography.

Automated three-dimensional analysis of mitral annular dynamics in patients with myocardial infarction using automated mitral annular tracking method

BACKGROUND

A newly developed automated mitral annular tracking method (AMAT) has recently become available and enables us to perform automated analysis of mitral annular dynamics.

PURPOSE

To evaluate mitral annular dynamics using AMAT.

METHODS

AMAT was performed using a Toshiba Aplio SSA-770 ultrasound system in 15 normal healthy volunteers (group N), 16 patients with anterior MI (group A), and 12 inferior MI (group B). The distance between an annular point at end-diastole and at end-systole (distance D) was automatically measured using AMAT at the basal portion of the anterior, lateral, posterior, inferior, and inferoseptal wall. The angle between the mitral annular plane at end-diastole and the direction of movement of each mitral annular point from end-diastole to end-systole (angle A) was also automatically measured at all five mitral annular points. The coefficients of variation (CV) of both distance D and of angle A were calculated as indices of asynchrony of mitral annular dynamics.

RESULTS

CV of distance D in group A (22 +/- 9% (P < 0.01 vs group N)) and group B (22 +/- 10% (P < 0.01 vs group N)) were both significantly larger than in group N (13 +/- 4%). CV of angle A in group A (15 +/- 10% (P < 0.05 vs group N)) and group B (15 +/- 10% (P < 0.05 vs group N)) were also significantly larger than that in group N (8 +/- 3%).

CONCLUSION

Automated analysis using AMAT showed that mitral annular dynamics of patients with MI were less symmetrical than in normal healthy volunteers.

Color encoding of endocardial motion improves the interpretation of contrast-enhanced echocardiographic stress tests by less-experienced readers

BACKGROUND

We hypothesized that color encoding of endocardial motion could aid less-experienced readers in detection of wall-motion abnormalities at rest and stress in patients with poor acoustic windows.

METHODS

Color-encoded images (color kinesis) were obtained at rest and peak dobutamine stress in 4 standard views during intravenous infusion of contrast agent in 117 patients with poorly visualized endocardium. In 101 of 117 patients (86%), in whom contrast enhancement allowed endocardial tracking, images were reviewed by two expert readers without color overlays. Each reader graded regional wall motion as normal, abnormal, or uninterpretable, and their consensus grades served as a gold standard. The same images were then reviewed and graded with and without color overlays by 3 cardiology fellows. The accuracy of the interpretation was calculated against the gold standard separately for the 3 vascular territories (left anterior descending, left circumflex, and right coronary arteries) and averaged for the 3 fellows.

RESULTS

With the addition of color encoding: (1) the number of uninterpretable segments decreased by 55% at rest and 61% at peak stress; and (2) all 3 fellows reached higher levels of accuracy in all 3 vascular territories both at rest (6%-82% average) and at stress (73%-80%).

CONCLUSION

The addition of color encoding of wall motion to contrast-enhanced images obtained in patients with poor acoustic windows during stress tests improves the interpretation of regional left ventricular function by less-experienced readers.

Tissue cardiomyoplasty using bioengineered contractile cardiomyocyte sheets to repair damaged myocardium: their integration with recipient myocardium

BACKGROUND

We hypothesized that tissue-engineered contractile cardiomyocyte sheets without a scaffold would show histological and electrical integration with impaired myocardium, leading to the regeneration of infarcted myocardium.

METHODS

Neonatal rat cardiomyocytes were cultured on Poly(N-isopropylacrylamide)-grafted polystyrene dishes and detached as a square cell sheet at 20 degrees C. Two sheets were stacked to make thicker contractile cardiac sheets. In cross-section, the stacked sheets looked like homogeneous heart-like tissue. Two weeks after rats were subjected to left anterior descending (LAD) ligation, two treatments were conducted: 1) cardiomyocyte sheet implantation (T group, n=10), and 2) fibroblast sheet implantation (F group, n=10). The control group underwent no additional treatment (C group, n=10).

RESULTS

Echocardiography demonstrated that cardiac performance was significantly ameliorated in the T group 2, 4, and 8 weeks after implantation. The cardiomyocyte sheets became attached to the infarcted myocardium, showed angiogenesis, expressed connexin-43, and appeared as homogeneous tissue in the myocardium Electrophysiological experiments showed a QRS complex with one peak in the treated scar area in the T group, but two peaks, indicative of branch block, in that of the other groups. Furthermore, the threshold for pacing of the recipient heart was lower in the T group than in the other groups.

CONCLUSIONS

Cardiomyocyte sheets integrated with the impaired myocardium and improved cardiac performance in a model of ischemic myocardium. Techniques using such tissue-engineered cell sheets are introducing the promising concept of tissue cardiomyoplasty to the field of regenerative medicine.

Usefulness of left ventricular diastolic wall motion abnormality as an early predictor of left ventricular dilation after a first acute myocardial infarction

To determine the relation between regional diastolic wall motion abnormality and left ventricular remodeling after acute myocardial infarction (AMI), Doppler echocardiography and color kinesis with assessment of global and regional systolic and diastolic functions were performed in 84 patients who developed AMI within 24 hours of admission. In a multivariate logistic regression analysis, the percentage of left ventricular myocardial segments with diastolic wall motion abnormality (p = 0.008), absence of myocardial viability (p = 0.01), and overall diastolic function (p = 0.001) were predictors of remodeling after AMI.

Quantitative polar representation of left ventricular myocardial perfusion, function and viability using SPECT and cardiac magnetic resonance: initial results

BACKGROUND

The clinical management of patients with coronary artery disease (CAD) often involves a complex assessment of the extent and severity of changes in left ventricular (LV) myocardial perfusion, function and viability. We aimed to explore the feasibility of integrative quantitative representation of LV perfusion, function and viability in adjacent polar plots. In order to assess the clinical usefulness of the quantitative methods, we also explored the relationship and determined the agreement between visual scoring and quantitative measurement of regional perfusion and function.

METHODS

Ten patients with CAD underwent rest and stress (99m)Tc-tetrofosmin single photon emission computed tomography (SPECT) and cardiac magnetic resonance (CMR) imaging. Software was developed in-house for generating polar plots from semi-automatic quantification of rest and stress perfusion from SPECT, function from cine CMR and viability from delayed contrast enhancement (DE) CMR. The agreement between visual assessment and quantification of both perfusion and function was tested by Kendall's coefficient of concordance (W).

RESULTS

Polar plots were created using quantitative data from the semi-automatic analysis of perfusion, function and viability. Kendall's W for agreement between quantitative measurement and visual scoring was 1.0 (P<0.001) for perfusion and 0.85 (P<0.001) for function.

CONCLUSIONS

Side-by-side quantitative polar representation of LV perfusion, function and viability is feasible and may aid in the complex assessment of these parameters. The agreement between quantitative measurement and visual scoring was very good for both perfusion and function.

Diastolic wall motion abnormality after myocardial infarction: relation to neurohormonal activation and prognostic implications

BACKGROUND

Systolic wall motion abnormality (WMA) after acute myocardial infarction (AMI) is a major determinant of outcome; the presence and importance of diastolic WMA after AMI are unknown. We therefore sought to detect diastolic WMA using color kinesis and to assess its relation to neurohormonal activation and its prognostic importance in a consecutive population with a first AMI.

METHODS

Complete color-encoded color kinesis and 2-dimensional and Doppler echocardiography were performed in 149 consecutive patients with documented first AMI within 24 hours of their admission. N-terminal pro-brain natriuretic peptide was measured 3 days after AMI. Study end point was cardiac death or readmission for heart failure.

RESULTS

Diastolic area of WMA exceeded the systolic area in all but 5 patients (97%) and was significantly correlated with brain natriuretic peptide (unadjusted beta = .67, P < .0001; adjusted for systolic function, age, Killip class, and overall diastolic function beta = .27, P = .007). Diastolic WMA was also correlated with the number of diseased vessels on coronary angiography (beta = .59, P < .0001). During follow-up, 25 patients died and 11 were readmitted because of recurrent heart failure. On univariate analysis, the area of diastolic WMA was a predictor of the composite end point (hazard ratio 1.07 [95% CI 1.05-1.09], P < .0001) and remained a predictor on multivariate Cox analysis after adjustment of well-known risk factors, left ventricular systolic and overall diastolic functions (hazard ratio 1.09 [95% CI 1.06-1.15], P < .001).

CONCLUSION

The extent of diastolic WMA can be assessed early after AMI using color kinesis. Diastolic WMA is associated with neurohormonal activation and angiographic severity of coronary artery disease and provides independent prognostic information.

Two-dimensional strain-a novel software for real-time quantitative echocardiographic assessment of myocardial function

OBJECTIVES

We sought to assess the feasibility of 2-dimensional strain, a novel software for real-time quantitative echocardiographic assessment of myocardial function.

METHODS

Conventional and a novel non-Doppler-based echocardiography technique for advanced wall-motion analysis were performed in 20 patients with myocardial infarction and 10 healthy volunteers from the apical views. Two-dimensional strain is on the basis of the estimation that a discrete set of tissue velocities are present per each of many small elements on the ultrasound image. This software permits real-time assessment of myocardial velocities, strain, and strain rate. These parameters were also compared with Doppler tissue imaging measurements in 10 additional patients.

RESULTS

In all, 80.3% of infarct and 97.8% of normal segments could be adequately tracked by the software. Peak systolic strain, strain rate, and peak systolic myocardial velocities, calculated from the software, were significantly higher in the normal than in the infarct segments. In the 10 additional patients, velocities, strain, and strain rate obtained with the novel software were not significantly different from those obtained with Doppler tissue imaging.

CONCLUSION

Two-dimensional strain can accomplish real-time wall-motion analysis, and has the potential to become a standard for real-time automatic echocardiographic assessment of cardiac function.

Effects of Postischemic Regional Left Ventricular Diastolic Wall Motion Abnormalities or Delayed Relaxation Following Coronary Vasospasm on Global Diastolic Function

BACKGROUND

Regional left ventricular (LV) diastolic wall motion abnormalities detected by color kinesis (CK), an echocardiographic technique, may be a more sensitive measure to postischemic damage following coronary spasm than parameters of global diastolic function.

METHODS AND RESULTS

Regional LV diastolic wall motion was evaluated by using CK in 18 patients with variant angina on the day following coronary spasm, which was induced by intracoronary acetylcholine. Fractional regional LV cavity area expansion in the short-axis view during the first 30% of the LV filling time, was used to identify postischemic asynchronous diastolic wall motion. Regional delayed relaxation was observed in any of the LV regions in all the patients, who were divided into 2 groups (Group S: 7 patients with single-vessel spasm with regional delayed relaxation in one area. Group M: 11 patients with multivessel spasm or spasm of the proximal left anterior descending branch with regional delayed relaxation in multiple areas). In Group S, no abnormality (0%) was noted in any of the indexes of global diastolic function including the isovolumic relaxation time, the ratio of peak rapid filling to peak atrial filling velocities and the deceleration time. In contrast, in 5 (45%) of the Group M patients, abnormalities were noted in all of those indexes.

CONCLUSIONS

Postischemic regional LV-delayed relaxation following coronary vasospasm was detected sensitively by analysis of CK images. The indexes of global LV diastolic function are insensitive to postischemic damage following single vessel spasm, although they are somewhat sensitive following multivessel spasm.

Noninvasive mapping of left ventricular electromechanical asynchrony by three-dimensional echocardiography and semi-automatic contour detection

A system for analyzing left ventricular (LV) electromechanical asynchrony based on transesophageal 3-dimensional echocardiography (3-DE) and semi-automatic endocardial contour detection is described. Eighteen consecutive patients underwent 3-DE. Using TomTec 4DLV software, a 3-dimensional endocardial surface was reconstructed throughout the cardiac cycle. Matlab software generated color-coded polar maps, displaying regional LV displacement and its timing. At the segmental level, Bland-Altmann assessment showed intraobserver variability of LV displacement of 0.1 +/- 3.0 mm and timing of -5.6 +/- 160 ms (bias +/- 2 SD) for all segments and -1.6 +/- 94 ms for the nonapical segments. The combination of 3-DE and semi-automatic contour detection is feasible and provides unique information for assessing regional LV endocardial displacement and electromechanical asynchrony.

Assessment of regional myocardial strain by a novel automated tracking system from digital image files

Myocardial strain imaging by Doppler tissue echocardiography is a useful method to quantify regional left ventricular function. However, this method has a problem of its Doppler angle dependency. We attempted to quantify myocardial strain by a newly developed automated tracking system from digital image files. In 6 anesthetized open-chest dogs, a pair of ultrasonic crystals was implanted at the inner site and outer site of the left ventricular wall to measure myocardial radial strain. B-mode echocardiographic images and trajectories of crystals were recorded simultaneously. Three conditions were examined by intravenous infusion of dobutamine. We used a pattern matching algorithm, which allowed us to track objects from one frame to the next. In 18 image sequences obtained in the 6 dogs, there was an excellent correlation in maximal myocardial strain between the two methods ( r = 0.92, P < .0001). Thus, this system is a promising tool to provide automated quantification of regional myocardial strain.

Diagnosis of multivessel coronary vasospasm by detecting postischemic regional left ventricular delayed relaxation on echocardiography using color kinesis

BACKGROUND

It is not known whether multivessel coronary spasm occurs spontaneously in patients who have variant angina (VA) with demonstrated multivessel spasm induced by intracoronary injection of acetylcholine (ACh). Regional left ventricular (LV) diastolic dysfunction or wall motion abnormality may persist after an episode of coronary vasospasm. Color kinesis (CK) is a recent development that facilitates the echocardiographic evaluation of regional diastolic wall motion.

METHODS AND RESULTS

Regional diastolic wall motion was evaluated using CK in 26 patients with VA within 1 week of the last episode of angina. The LV segmental filling fraction in the short-axis view during the first 30% of the diastolic filling time, expressed as a percentage, was used to objectively identify postischemic diastolic endocardial motion asynchrony. Diastolic asynchrony or regional LV delayed relaxation was noted in all 26 (100%) patients and in 14 (54%) it was detected in multiple vascular territories, suggesting multivessel spasm. Multivessel spasm was induced by ACh in 11 (79%) of the patients with suspected multivessel spasm by CK. In 11 (92%) of the 12 patients with multivessel spasm induced by ACh multiple regions of delayed relaxation had been noted by CK. The regions of delayed relaxation were largely consistent with the territories perfused by the arteries reacting to ACh (sensitivity: 96%, specificity: 91%).

CONCLUSION

ACh induced spasm in the same coronary arteries as those perfusing the regions with delayed diastolic wall motion detected by CK in most of the patients with VA, suggesting that multivessel spasm does occur spontaneously in patients with susceptible arteries.

Automated quantitative assessment of wall motion in patients with poor acoustic windows

BACKGROUND

No technique exists for objective evaluation of left ventricular wall motion in contrast-enhanced images. We tested a new technique for quantification of regional fractional area change using contrast-enhanced power modulation imaging with color kinesis.

METHODS

The feasibility of this technique for detecting acute ischemia was first tested in 11 pigs. Next, the accuracy for detecting resting wall-motion abnormalities was determined in 52 patients requiring contrast and compared with conventional interpretation of 2-dimensional images by inexperienced readers. Expert interpretation of 2-dimensional images served as the gold standard.

RESULTS

In pigs, coronary occlusion resulted in reversible hypokinesis and reduced regional fractional area change. In patients with poor acoustic windows, this technique's accuracy for quantitative detection of resting wall-motion abnormalities was 86% compared with 81% for conventional interpretation by inexperienced readers (P <.01).

CONCLUSIONS

Regional wall motion can be accurately assessed using color-encoded power modulation imaging for patients requiring contrast. This technique may prove a useful diagnostic aid to echocardiographers of varying levels of experience.

Global longitudinal strain: a novel index of left ventricular systolic function

BACKGROUND

Echocardiographic estimation of global left ventricular (LV) function is subjective and time consuming. Our aim was to develop a novel approach for assessment of global LV function from 2-dimensional echocardiographic images

METHODS

Novel computer software for tissue tracking was developed and applied as follows: digital loops were acquired from apical 2-, 3-, and 4-chamber views and a line was loosely traced along the LV endocardium at the frame wherein it was best defined. Around this line, the software selected natural acoustic markers moving with the tissue. Automatic frame-by-frame tracking of these markers during the heart cycle yielded a measure of contractility along the selected region of interest. Global longitudinal strain (GLS) and GLS rate (GLSR) were calculated for the entire U-shaped length of LV myocardium (basal, mid, and apical segments of 2 opposite walls in each view). To test this software, computer-derived GLS and GLSR were analyzed by a nonechocardiographer, blinded to the echocardiographic interpretation, in 27 consecutive patients after myocardial infarction (MI) (age 64.4 +/- 12.9 years; 19 men; mean wall-motion score index of 1.79 +/- 0.44) and compared with those obtained in 12 consecutive control patients (age 59.0 +/- 9.7 years; 8 women), with a normal echocardiographic study.

RESULTS

GLS and GLSR, averaged from the 3 apical views, differed significantly in patients post-MI compared with control patients (GLS -14.7 +/- 5.1% vs -24.1 +/- 2.9% and GLSR -0.57 +/- 0.21/s vs -1.02 +/- 0.09/s for patients post-MI vs control patients, respectively; both P <.0001). There was a good linear correlation between the wall-motion score index and the GLS and GLSR (R = 0.68 and R = 0.67, respectively; both P <.0001). A cut-off value for GLS of -21% had 92% sensitivity and 89% specificity and a cut-off value for GLSR -0.9/s had 92% sensitivity and 96% specificity for the detection of patients post-MI.

CONCLUSIONS

GLS and GLSR are novel indices for assessment of global LV function from 2-dimensional echocardiographic images. Early validation studies with the method are suggestive of high sensitivity and specificity in the detection of LV systolic dysfunction in patients post-MI.

Diagnosis of coronary vasospasm by detection of postischemic regional left ventricular delayed relaxation using echocardiographic evaluation with color kinesis

BACKGROUND

Coronary vasospasm has been diagnosed by invasive provocative procedures during coronary arteriography. It would be useful to have a reliable, noninvasive, and safe diagnostic method for coronary vasospasm. Regional left ventricular (LV) diastolic dysfunction may persist without systolic dysfunction after an episode of coronary vasospasm. Color kinesis (CK) has been recently developed to facilitate the echocardiographic evaluation of regional wall motion.

HYPOTHESIS

Color kinesis may be useful for diagnosis of coronary vasospasm by detection of postischemic regional LV diastolic wall motion abnormality.

METHODS

Fifty-one consecutive patients with the last chest symptom within 2 weeks (4 +/- 3 days) were studied echocardiographically. Regional fractional area change during the first 30% of LV filling time in percentage of the segmental end-diastolic area change (CK diastolic index) was used to identify diastolic endocardial motion asynchrony.

RESULTS

After diagnostic coronary arteriography with spasm provocation, 26 patients were diagnosed with coronary spastic angina (CSA) and the other 25 with chest pain syndrome (CPS). Regional delayed relaxation (CK-diastolic index < or = 50%) or diastolic asynchrony had been observed in at least one region in 25 (96%) patients with CSA, whereas it had been noted in 2 (8%) patients with CPS. In 17 (65%) patients with CSA, it had been detected in multiple vascular territories, suggesting multivessel spasm. The diastolic asynchrony disappeared in CSA after a month of angina-free period.

CONCLUSION

Analysis of CK images allows identification of regional LV delayed relaxation or diastolic asynchrony in patients with coronary vasospasm, differentiating them from patients with chest pain syndrome (sensitivity 96%, specificity 92%).

Acute Effects of Diltiazem on Regional Left Ventricular Diastolic Filling Dynamics in Patients With Hypertrophic Cardiomyopathy as Assessed by Color Kinesis

BACKGROUND

The effect of calcium antagonists on regional left ventricular (LV) filling dynamics in patients with hypertrophic cardiomyopathy (HCM) is not well known, so the present study evaluated the results of echocardiography with color kinesis (CK) analysis during diltiazem infusion.

METHODS AND RESULTS

Nineteen patients (16 men, 3 women; mean age 55+/-15 years) underwent echocardiography with CK analysis during intravenous diltiazem (10 mg/2 min). Using the quantitative CK software the LV short-axis image was divided into 6 segments and the percent endocardial expansion at the early, mid- and late-diastolic filling time was averaged for all segments, with the standard deviation of the mean used as an index of diastolic asynchrony (asynchrony index). The regional mean filling time was also measured for the corresponding segments. As global diastolic parameters, the global filling time, peak filling rate, and the time-to-peak filling were calculated. After the administration of diltiazem, the asynchrony index was decreased for all three diastolic filling times. Diltiazem shortened the mean filling time overall, especially in the posterior and lateral wall segments. These findings were associated with significant improvement in the CK-derived global diastolic parameters.

CONCLUSIONS

Diltiazam has a favorable effect on LV diastolic asynchrony, which may account for the acute changes in global LV relaxation.

Simultaneous real-time echocardiographic imaging of myocardial perfusion and regional function using color-encoded, contrast-enhanced power modulation

We hypothesized that color-encoded, contrast-enhanced, power modulation imaging could allow simultaneous quantification of myocardial perfusion and regional left ventricular function. We studied 12 anesthetized, closed-chest pigs at baseline, during acute ischemia, and during reperfusion, and 8 patients after acute myocardial infarction. Color kinesis was used to color encode endocardial motion during real-time contrast perfusion imaging with high-energy ultrasound pulses. Wall motion was assessed by calculating regional fractional area changes. Translation-free perfusion analysis was performed in automatically identified myocardial regions of interest. Steady-state intensity and postimpulse rate of contrast replenishment were calculated. In all animals, ischemia caused reversible changes in the images and the perfusion- and function-calculated indices. A significant decrease in pixel intensity (14%) and contrast replenishment rate (66%) in left anterior descending coronary artery segments, in agreement with fluorescent microspheres measurements, coincided with a decrease in fractional area change (34%). For patients, respective perfusion and function indices were 61%, 51%, and 58% lower in segments where perfusion defects, regional wall-motion abnormalities, or both were noted in gray scale images. Color-encoded, contrast-enhanced power modulation allows simultaneous real-time imaging and quantitative analysis of myocardial perfusion and regional left ventricular function.

Quantitative analysis of left ventricular regional wall motion with color kinesis during abdominal aortic cross-clamping

OBJECTIVES

The authors aimed to establish a technique for quantitative analysis of regional wall motion abnormality (RWMA) using color kinesis (CK) of transesophageal echocardiography (TEE) in surgical patients. This technique was used to determine whether RWMAs develop de novo after infrarenal aortic cross-clamping in patients undergoing vascular surgery with a preoperative dipyridamole thallium stress test (DTST).

DESIGN

An observational study.

SETTING

University hospital.

PARTICIPANTS

Thirty-eight patients undergoing infrarenal abdominal aortic aneurysm resection or aortofemoral bypass.

MEASUREMENTS AND MAIN RESULTS

CK images of the left ventricle (LV) were obtained from the midventricular transgastric short-axis view before and after infrarenal aortic cross-clamping using TEE and analyzed off-line using custom software. The predictive value of the category "reversible perfusion defect" (RD) was also estimated from DTST for predicting new RWMAs with CK. CK analysis is suitable for clinical use based on the comparison with conventional two-dimensional echocardiogram measurements and interobserver variability. CK analysis showed all 7 patients with persistent perfusion defects on DTST had RWMAs. New RWMAs occurred in 2 of 9 patients with RD and in 2 of 15 patients with normal DTST, indicating that there was no significant difference between RD and normal DTST in the incidence of new RWMAs.

CONCLUSIONS

A new method is available for clinical use, which is capable of visualizing RWMAs. These results suggest that new RWMAs introduced by aortic cross-clamping occur irrespective of the risk as assessed by preoperative DTST. CK with the new analysis method might be a useful tool to quantitatively evaluate RWMAs during surgery.

Interpretation of Left Ventricular Wall Motion During Stress Testing

This article describes the obstacles to stress echocardiographic interpretation, and reviews the techniques currently available that offer a more objective approach to stress wall motion analysis than the conventional visual methodology. These techniques include Doppler-based methods, such as myocardial Doppler velocity and strain rate imaging, as well as automated border detection techniques, such as acoustic quantification and color kinesis.

New Techniques for the Assessment of Regional Left Ventricular Wall Motion

The assessment of regional left ventricular (LV) function has been an important yet unresolved problem since the introduction of echocardiography as a diagnostic tool. Abnormal regional LV wall motion is an early finding in multiple cardiac pathologies and its diagnosis is of critical importance. In the last few years diagnostic procedures based on combined use of existing echocardiographic technologies were geared toward improving the accuracy of detection of baseline and/or induced regional wall motion abnormalities. One of the assumptions is that the combination of reduced LV wall thickening and reduced myocardial velocities can be used to accurately diagnose regional myocardial dysfunction. In this article we will discuss several new techniques for the quantification of regional LV function using Doppler echocardiography.

Assessment of Global and Regional Left Ventricular Diastolic Function in Hypertensive Heart Disease Using Automated Border Detection Techniques

Acoustic quantification (AQ) and color kinesis (CK) are techniques that involve automated detection and tracking of endocardial borders. These methods are useful for the evaluation of global and regional left ventricular (LV) systolic function and more recently have been applied to evaluating LV diastolic performance. Assessment of diastolic dysfunction in hypertensive heart disease is a relevant clinical issue in which these techniques have proven useful. The diastolic portion of left atrium and LV AQ area waveforms are frequently abnormal in patients with left ventricular hypertrophy (LVH). Left ventricular AQ curves consistently demonstrate reduced rapid filling fraction (RFF) and peak rapid filling rate (PRFR), elevated atrial filling fraction (AFF), peak atrial filling rate (PAFR), and reductions in the ratio PRFR/PAFR. Acoustic quantification complements traditional Doppler echocardiographic evaluation of global diastolic function. Many patients with significant LVH and normal Doppler diastolic parameters can be identified as having diastolic dysfunction with AQ. In addition, CK has allowed the evaluation of regional diastolic performance in hypertensive patients. Regional filling curves obtained from CK have demonstrated that endocardial diastolic motion is commonly delayed and heterogeneous in patients with LVH.

Second-generation tissue Doppler with angle-corrected color-coded wall displacement for quantitative assessment of regional left ventricular function

To test the hypothesis that a new tissue Doppler (TD) approach using angle-correction and transformation of velocity data to color-coded displacement data may objectively quantify regional left ventricular function, in vitro experiments were first performed with an oscillating echo target precisely controlled by a microstepping motor. Displacement varied from 1 to 15 mm (60 to 130 cycles/min) at angles of 0 degrees and 45 degrees to the echo transducer. Custom software transformed TD data to displacement data. Sixty-five subjects were then studied: 35 with wall motion abnormalities and 30 normal controls. Results were compared with independent visual assessment and caliper measurements of endocardial excursion from gray-scale images. In vitro displacement imaging strongly correlated with true displacement (r = 0.99, p <0.0001). In humans, peak transmural displacement discriminated normal results (6.3 +/- 3.2 mm) from hypokinesia (2.7 +/- 1.8 mm, p <0.05), akinesia (0.4 +/- 1.2 mm, p <0.05) from hypokinesia, and dyskinesia (-1.9 +/- 1.2 mm, p <0.05) from akinesia. Normal subendocardial displacement was 5.9 +/- 2.9 versus 4.0 +/- 3.9 mm in the epicardial layer (p <0.01). This displacement gradient was absent in abnormal segments. Displacement data correlated with endocardial excursion by calipers (parasternal views: r = 0.86, all views: r = 0.79, both p <0.0001). Overall accuracy of displacement imaging was 82% (kappa = 0.71) versus 66% (kappa = 0.43) for visual assessment with caliper data as the standard of reference. Angle-corrected displacement imaging was superior to routine visual assessment and is a promising new method to quantify regional left ventricular function.

Quantitative echocardiographic assessment of regional wall motion and left ventricular asynchrony with color kinesis in cardiac surgery patients

Conventional echocardiographic interpretation of regional wall motion abnormalities is subjective and experience dependent. Delayed contraction in the ejection phase (tardokinesis) and regional systolic asynchrony, sensitive markers of myocardial ischemia, cannot be accurately assessed visually. We used color kinesis (CK), a technique that evaluates spatiotemporal patterns of endocardial motion, to objectively detect regional wall motion abnormalities in patients undergoing coronary bypass surgery, and we compared it with conventional assessment of grayscale images by less experienced reviewers; we used expert grading as the gold standard for comparisons. Quantitative CK analysis agreed more closely with expert grading than less experienced reviewers (kappa coefficients, 0.74 versus 0.52 and 0.5). Global tardokinesis, identified in 9 of 26 patients (2 with normal fractional area change), was associated with an increased index of systolic asynchrony. Regional tardokinesis was identified in 48 of 150 segments: 27 segments had a normal magnitude of wall motion, 18 were hypokinetic, and 3 were severely hypokinetic/akinetic. Mildly hypokinetic segments showed delayed systolic motion, whereas residual motion of severely hypokinetic/akinetic segments occurred in early systole, reflecting passive effects produced by adjacent myocardial contraction. Quantitative CK may be a useful supplement to visual assessment, particularly for less experienced readers. By diagnosing tardokinesis, common among cardiac surgical patients even with normal standard ejection phase indices, quantitative CK may improve the intraoperative detection of regional ischemic changes.

IMPLICATIONS

Quantitative color kinesis allows for objective and sensitive intraoperative echocardiographic assessment of abnormal spatial and temporal patterns of regional ventricular wall motion, with potentially important implications for improving myocardial ischemia detection in patients undergoing cardiac surgery.