Left Ventricular Long-axis View Research Articles

Automated detection scheme for acute myocardial infarction using convolutional neural network and long short-term memory.

The early detection of acute myocardial infarction, which is caused by lifestyle-related risk factors, is essential because it can lead to chronic heart failure or sudden death. Echocardiography, among the most common methods used to detect acute myocardial infarction, is a noninvasive modality for the early diagnosis and assessment of abnormal wall motion. However, depending on disease range and severity, abnormal wall motion may be difficult to distinguish from normal myocardium. As abnormal wall motion can lead to fatal complications, high accuracy is required in its detection over time on echocardiography. This study aimed to develop an automatic detection method for acute myocardial infarction using convolutional neural networks (CNNs) and long short-term memory (LSTM) in echocardiography. The short-axis view (papillary muscle level) of one cardiac cycle and left ventricular long-axis view were input into VGG16, a CNN model, for feature extraction. Thereafter, LSTM was used to classify the cases as normal myocardium or acute myocardial infarction. The overall classification accuracy reached 85.1% for the left ventricular long-axis view and 83.2% for the short-axis view (papillary muscle level). These results suggest the usefulness of the proposed method for the detection of myocardial infarction using echocardiography.

Effects of adenosine stress on myocardial perfusion in healthy mice

Objective To explore the effects of adenosine stress on myocardial perfusion in healthy mice by myocardial contrast echocardiography (MCE). Methods MCE was carried out to quantify regional myocardial perfusion at rest and during adenosine stress using a VEVO2100 system in 26 C57BL/6 mice.Echocardiography images from standardized parasternal long axis and short axis at papillary muscle level were consecutively acquired in real-time. All dynamic images were recorded for off-line analysis.Left ventricular myocardial perfusion quantitative parameters were acquired both under resting status and during adenosine stress. Replenishment curves of myocardial contrast were obtained and myocardial blood flow(MBF) was calculated. Results Twenty-six experimental animals successfully underwent MCE before and during adenosine stress. There was no significant difference in heart rate, left ventricular structure and functional parameters before and during adenosine stress (all P>0.05). Rates of signal rise β values which were used to estimate blood velocity of middle anterior septum and posterior wall in left ventricular long-axis view and anterior wall, lateral wall, inferior wall and septal wall in short-axis view at papillary muscle increased significantly during stress compared with those at rest (all P 0.05). The MBF in each segment of the myocardium increased significantly during stress compared with those in resting state (all P<0.05). Conclusions The physiological characteristics of myocardial perfusion in mice before and during adenosine stress were preliminarily obtained, which provided a basis for the application of adenosine stress echocardiography in cardiovascular disease models such as coronary heart disease in mice. Key words: Echocardiography, stress; Adenosine; Mice; Myocardial perfusion

Early assessment of the left ventricular function by epirubicin-induced cardiotoxicity in postoperative breast cancer patients.

Epirubicin (Epi) is a potent and effective drug for many malignant cancers with serious cardiotoxicity. Therefore, layer-specific two-dimensional speckle tracking echocardiography (2D-STE) was used to evaluate the longitudinal and circumferential systolic function of the left ventricular for the early detection of cardiotoxicity in this retrospective work. Overall, 130 female patients with postoperative breast cancer who did not receive radiotherapy were classified into three groups: Group A (control group, n=40) without any chemotherapy; Group B (n=44) administered Epi at 180~240mg/m2 ; and Group C (n=46) administered Epi at ≥360mg/m2 . Peak and global systolic longitudinal strains (GLS) in the total and endocardium, mid-myocardium, and epicardium were measured and calculated from apical four-chamber, apical two-chamber, and left ventricular long-axis views, respectively. Peak and global circumferential strains (GCS) in the total and endocardium, mid-myocardium, and epicardium were measured and calculated from mitral annulus, papillary muscle, and apical levels of the short-axis view, respectively. The total GLS and GLS of the endocardium in every view were significantly reduced in group C compared with both groups A and B (P<.05), but there was no significant difference between groups A and B (P>.05). The GLS of the epicardium and mid-myocardium in groups B and C were not significantly reduced (P>.05). There were no significant differences in the total GCS and layer-specific GCS of endocardium, mid-myocardium, and epicardium among the three groups (P>.05). Left ventricular longitudinal systolic dysfunction was detected. Moreover, an impaired endocardium was also detected in an early assessment by layer-specific 2DSTE.

Identification of the heart wall and chamber based on temporal change of ultrasonic scatterer distribution

In most current methods for evaluating the cardiac function by ultrasound, the heart wall area is identified manually by an examiner. To eliminate examiner dependence and to improve usability, an automatic heart wall identification method is desirable. Identification based on only echogenicity often fails because of low echogenicity of some areas of the heart wall. In the present study, to determine more essential features, we focused on the relative temporal change of ultrasonic scatterer distribution and proposed three features for identification of the heart wall and the chamber: cross-correlation of RF signals, that of envelopes, and spatial dispersion of movement vectors in small regions. In an in vivo experiment, using echogenicity and the three features, we identified the heart wall and the chamber in the left ventricular long-axis view, resulting in criteria of separability J of 1.69, 1.40, and 3.02 using these features compared with the result of 0.979 using echogenicity.

Dynamic estimation of myocardial deformation using ultrasound RF-data: A preliminary study.

Analytic minimization (AM) is one of elastography algorithms. In this study, a healthy male volunteer lying in lateral position was examined by an ultrasound system. The left ventricular long-axis view of the heart was acquired and the ultrasound radio frequency (RF) data were stored for estimation of myocardial deformation. The methods of AM and Linear polynomial curve fitting were used to calculate the displacement and strain, respectively. The myocardial deformation was dynamically estimated. The strain maps at approximately 50ms, 140ms, and 240ms after the beginning of the ventricle systole indicate the contraction of different myocardial segments. This study provides a potential method to assess the survival myocardium in patients with myocardial infarction in future study.

Normal and shear strains of the left ventricle in healthy human subjects measured by two-dimensional speckle tracking echocardiography

BackgroundAnimal studies have shown that shear deformation of myocardial sheets in transmural planes of left ventricular (LV) wall is an important mechanism for systolic wall thickening, and normal and shear strains of the LV free wall differ from those of the interventricular septum (IVS). We sought to test whether these also hold for human hearts.MethodsThirty healthy volunteers (male 23 and female 7, aged 34 ± 6 years) from Outpatient Department of the University of Tokyo Hospital were included. Echocardiographic images were obtained in the left decubitus position using a commercially available system (Aloka SSD-6500, Japan) equipped with a 3.5-MHz transducer. The ECG was recorded simultaneously. The peak systolic radial normal strain (length change), shear strain (angle change) and time to peak systolic radial normal strain were obtained non-invasively by two-dimensional speckle tracking echocardiography.ResultsThe peak systolic radial normal strain in both IVS and LV posterior wall (LVPW) showed a trend to increase progressively from the apical level to the basal level, especially at short axis views, and the peak systolic radial normal strain of LVPW was significantly greater than that of IVS at all three levels. The time to peak systolic radial normal strain was the shortest at the basal IVS, and increased progressively from the base to the apical IVS. It gradually increased from the apical to the basal LVPW in sequence, especially at short axis views. The peak of radial normal strain of LVPW occurred much later than the peak of IVS at all three levels. For IVS, the shear deformation was clockwise at basal level, and counterclockwise at mid and apical levels in LV long-axis view. For LVPW, the shear deformations were all counterclockwise in LV long-axis view and increased slightly from base to the apex. LVPW showed larger shear strains than IVS at all three levels. Bland-Altman analysis shows very good agreement between measurements taken by the same observer and by two independent observers.Conclusion“Myocardial sheets” theory also holds true for intact human LV. Moreover, dyssynchrony exists even in healthy human subjects, which should be considered when evaluating the diseased hearts.

Acute Myocardial Infarction Secondary to Thrombosis in the Right Coronary Sinus of Valsalva

A 78-year-old woman with a history of paroxysmal atrial fibrillation and hypertension presented with sudden chest pain, dyspnea, and severe hypoxia (O2 saturation=79%; arterial blood gas test results: Paco2 level=37.4 mm Hg and Pao2 level=46.1 mm Hg under high-flow oxygen administration). Electrocardiography showed ST elevation in the inferior leads. Transthoracic echocardiography showed hypokinesis of the right ventricular free wall and enlargement of the right ventricle with flattening of the interventricular septum during diastole (online-only Data Supplement Movie I). As clinical suspicion for pulmonary embolism associated with inferior myocardial infarction was high, emergent multidetector computed tomography (MDCT) was performed: no thrombi were found in the pulmonary artery, but a thrombus was observed in the right coronary sinus of Valsalva (Figure 1A and 1B). After MDCT, repeat echocardiography …

Value of prenatal ultrasound observation of subaortic conical connection in the diagnosis of complete transposition of great anteries

Objective To investigate the value of prenatal ultrasound observation of subaortic conical connection in the diagnosis of complete transposition of great arteries(TGA).Methods Echocardiography findings of 22 cases with complete TGA confirmed by autopsy were retrospectively analyzed and summarized.Results All cases were shown subaortic conical connection on two-dimensional echocardiography,the two great arteries were parallel in 18 cases on left ventricular long-axis view,the character of normal right ventricular outflow tract surrounding the aortic root disappeared in 17 cases.There were 13 cases with ventricular septal defect and 2 cases with left ventricular outflow tract obstruction.Aorta and pulmonary artery were shown in right anterior and left posterior position among 20 cases,and in anterior and posterior position in 2 cases.Conclusions Prenatal ultrasound observation of subaortic conical connection is of great value in the diagnosis of complete TGA. Key words: Ultrasonography,prenatal; Heart defects,congenital; Complete transposition of great arteries

Evaluation of left ventricular torsion by two-dimensional ultrasound speckle tracking imaging in heart transplant patients

Objective To evaluate the value of left ventricular (LV) torsion for assessing left ventricular function in adult heart transplant patients using two-dimensional speckle tracking imaging.Methods Basal and apical LV short-axis view and apical LV long-axis view of two-demensional images were acquired in 30 heart transplant patients and 17 healthy volunteers. Using two-dimensional strain software,LV basal and apical rotation versus time profiles were obtained at their short-axis level respectively. LV torsion was defined as apical rotation relative to the base, so the LV torsion versus time profiles could be drawn. LV basal rotation,apical rotation,global torsion and their time to peak were respectively measured,and the rate of LV untwisting was calculated. Statistical analysis was used to find the difference between the two groups and to investigate the relationship between LV torsion or the rate of LV untwisting and echocardiographic parameters. Results LV apical rotation and LV global torsion in heart transplant group were significantly lower than those in normal group. LV global torsion inversely correlated with LV end systolic volume,positively with LV ejection fraction. There was no significant difference between the two groups in the rate of LV untwisting. The rate of LV untwisting didn't correlate with echocardiographic parameters. Conclusions LV torsion can be measured exactly by two-dimensional speckle tracking imaging, it can be used to quantify LV global systolic function in heart transplant patients. Key words: Echocardiography; Heart transplantation; Ventricular function,left; Torsion; Speckle tracking imaging

Mechanism of Persistent Ischemic Mitral Regurgitation After Annuloplasty

We hypothesized that surgical annuloplasty for ischemic mitral regurgitation (MR) that displaces the posterior annulus anteriorly can potentially augment posterior leaflet (PML) tethering, leading to persistent MR. Relationships between leaflet configurations and persistent ischemic MR after the annuloplasty were investigated. In 31 patients with surgical annuloplasty for ischemic MR and 20 controls, posterior and apical displacement of the leaflet coaptation, the anterior leaflet (AML) and PML tethering angles relative to the line connecting annuli, coaptation length (CL), and the MR grade were quantified before and early after surgery in echocardiographic left ventricular long-axis views. Six of the 31 patients showed persistent MR despite annuloplasty. Compared with patients without persistent MR, those with MR showed no improvement in the left ventricular ejection fraction and systolic volume, similar reduction in the annular area, significant increase in posterior displacement of the coaptation (P<0.01), no improvement in AML tethering, greater worsening in PML tethering (P<0.01), and no increase in the CL. All tethering variables were significantly correlated with both preoperative and postoperative MR in univariate analysis, and reduced CL was the primary independent determinant of both preoperative and postoperative MR. Although increased AML tethering was the primary determinant of the preoperative CL (r2=0.46, P<0.0001), increased PML tethering was the primary determinant afterward (r2=0.60, P<0.0001). Although tethering of both leaflets is the major determinant of ischemic MR before surgical annuloplasty, both leaflets tethering but with predominant and augmented PML tethering is related to persistent ischemic MR after the annnuloplasty.

Regional Myocardial Systolic Function Assessed by Strain Tissue Doppler Imaging in Patients With Isolated Noncompaction of Left Ventricular Myocardium: A Study of Two Cases

Isolated noncompaction of the left ventricular myocardium (INVM) is associated with a high incidence of heart failure. However, it is difficult to determine accurately left ventricular (LV) systolic function because of the trabeculated ventricles. The purpose of this study was to clarify whether strain imaging could detect regional myocardial systolic function in 2 patients with INVM. We recorded myocardial strain profiles at the basal, mid-, and apical portions of the LV free wall and ventricular septum (VS) in the apical LV long-axis view. Case 1 (15-year-old male) was referred to our hospital because of ECG abnormalities. Case 2 (83-year-old female) was admitted to our hospital for congestive heart failure. Two-dimensional echocardiography in both patients showed numerous prominent trabeculations and deep intertrabecular recesses at the apex of the LV wall. Because of the trabeculations, it was difficult to determine accurately LV ejection fraction by 2-dimensional echocardiography. The percent fractional shortening of the LV (%FS) in both cases was within a normal range. However, the peak systolic strains at the apical, mid-, and basal portions of the LV free wall were lower in Case 2 (-12, -12, and -11%, respectively) than in Case 1 (-33, -37, and -37%, respectively). The peak systolic strains at the apical, mid-, and basal portions of the VS were also lower in Case 2 (-11, -16, and -11%, respectively) than in Case 1 (-27, -27, and -29%, respectively). We conclude that strain measurements are useful for evaluating regional myocardial systolic function in patients with INVM.

Effect of Aging on Diastolic Left Ventricular Myocardial Velocities Measured by Pulsed Tissue Doppler Imaging in Healthy Subjects

We evaluated the effect of aging on diastolic left ventricular (LV) wall motion velocity in 80 healthy persons with the use of pulsed tissue Doppler imaging. The wall motion velocity patterns were recorded at the middle regions of the LV posterior wall and ventricular septum in the parasternal (along the short axis) and apical (along the long axis) LV long-axis views. In the posterior wall, the peak early diastolic wall motion velocities (Ews) along both axes correlated inversely with age (long axis: r = –0.61, P < .0001; short axis: r = –0.55, P < .0001), and the peak atrial systolic wall motion velocities (Aws) along both axes correlated directly with age (long axis: r = 0.59, P < .0001; short axis: r = 0.65, P < .0001). In the ventricular septum, the Ew along the long axis correlated inversely with age ( r = –0.51, P < .0001), and the Aws along both axes correlated directly with age (long axis: r = 0.57, P < .0001; short axis: r = 0.53, P < .0001). The Ews along both axes at the posterior wall correlated directly with the peak early diastolic transmitral flow velocity. The Aws along both axes at the ventricular septum and posterior wall correlated directly with the peak atrial systolic transmitral flow velocity. The times from the second heart sound to the peak of the early diastolic waves of the ventricular septum and posterior wall along both axes significantly increased with age. The times from the aortic component of the second heart sound to the peak of the early diastolic motion velocities along both axes were significantly longer at the ventricular septum than at the posterior wall. Pulsed tissue Doppler imaging may be useful for evaluating the effect of aging on diastolic LV function in healthy persons. (J Am Soc Echocardiogr 1999;12:574-81.)

Assessment of Left Ventricular Systolic Wall Motion Velocity with Pulsed Tissue Doppler Imaging: Comparison with Peak dP/dt of the Left Ventricular Pressure Curve

To assess the usefulness of the tissue Doppler imaging variables for the evaluation of left ventricular (LV) systolic function, we compared variables obtained by the pulsed Doppler method with the LV ejection fraction (%EF) and the maximum value for the first derivative of LV pressure (peak dP/dt). We examined 65 patients, including 15 patients with noncardiac chest pain, 15 with ischemic heart disease, 15 with dilated cardiomyopathy, 10 with hypertensive heart disease, and 10 with asymmetric septal hypertrophic cardiomyopathy. The subendocardial systolic wall motion velocity patterns were recorded for LV posterior wall and ventricular septum in the parasternal LV long-axis view. The peak dP/dt was significantly lower in the hypertensive heart disease, hypertrophic cardiomyopathy, and dilated cardiomyopathy groups. The peak systolic velocity was lower and the time from the electrocardiographic Q wave to the peak of the systolic wave for the posterior wall was longer in the hypertensive heart disease (5.9 ± 0.5 cm/sec and 215 ± 21 msec, respectively), hypertrophic cardiomyopathy (6.2 ± 0.9 cm/sec and 217 ± 17 msec, respectively), and dilated cardiomyopathy (5.2 ± 0.8 cm/sec and 235 ± 26 msec, respectively) groups than in the noncardiac chest pain (7.7 ± 0.9 cm/sec and 187 ± 24 msec, respectively) and the ischemic heart disease (7.6 ± 0.8 cm/sec and 184 ± 22 msec, respectively) groups. In all groups, the peak systolic velocity and the time from the electrocardiographic Q wave to the peak of the systolic wave for the posterior wall correlated directly and inversely, respectively, with the %EF ( r = 0.59, p < 0.0001; r = –0.59, p < 0.0001) and the peak dP/dt ( r = 0.75, p < 0.0001; r = –0.68, p < 0.0001). Both tissue Doppler variables for the ventricular septum did not correlate with the %EF but roughly correlated with peak dP/dt. We conclude that the systolic LV wall motion velocity parameters obtained by pulsed tissue Doppler imaging may be useful for noninvasive evaluation of global LV systolic function in patients with no regional asynergy. (J Am Soc Echocardiogr 1998;11:442-9.)

Mitral valve protrusion assessed by use of B-mode echocardiography in dogs with mitral regurgitation

Abstract Objective To examine our hypothesis that changes of the mitral valve in dogs with mitral regurgitation lead to various degrees of protrusion of the cusp in individual dogs in systole. Design Assessing the mitral protrusion, using B-mode echocardiography in dogs with mitral regurgitation. Animals 33 dogs with chronic mitral regurgitation and 40 clinically normal dogs. Procedure The mitral valve was imaged in the right parasternal left ventricular long-axis view, and we measured the height (H) from the coaptation point or tip of the protruded cusp to the mitral annular plane. When the tip of the protruded cusp was located beyond the mitral annular plane extending into the left atrium, H was expressed as negative values. Results The H in clinically normal dogs was 3.7 ± 0.8 mm. In dogs with mitral regurgitation, the mitral cusp protruded toward the left atrium to various degrees, and H was −0.7 ± 1.9 mm (range, 2.9 to −5.0 mm). The 2 dogs in the latter group with the lowest H (−5.0 and −4.5 mm, respectively) presented typical mitral flail on B-mode images. The indices of left atrial and ventricular dimension (left atrial dimension/aortic dimension and left ventricular end-diastolic dimension/body weight, respectively) were significantly higher than those in the clinically normal dogs and were negatively correlated with H. Conclusion The mitral valve in individual dogs with mitral regurgitation has different degrees of protrusion. The degree of protrusion might be related to the hemodynamic condition in mitral regurgitation. (Am J Vet Res 1996;57:791–797)

Usefulness of transesophageal echocardiography in identifying small left ventricular apical thrombus

Objectives. The aim of this study was to determine whether transesophageal echocardiography could clarify the nature of equivocal echodense structures in the left ventricular apical region frequently found on transthoracic echocardiography by directing the ultrasound beam from the left ventricular base to the apex and achieving better image quality.Background. Transthoracic echocardiography often reveals an echogenic structure suggesting thrombus in the left ventricular apical region because of limited near-field resolution and echo vibration artifact in apical views.Methods. Thirty-six patients with coronary artery disease or dilated cardiomyopathy who had apical wall motion abnormalities and equivocal transthoracic echodense structures were studied with transesophageal echocardiography using special manipulation of the transesophageal probe for adequate imaging of the apical region. Left ventricular thrombus was defined when echogenic structures with a cleariy delineated margin adjacent to but distinct from the endocardium were observed in at least two different tomographic views in the four-chamber and left ventricular long-axis views during both systole and diastole.Results. Left ventricular thrombus (mean size 1.3 ± 0.7 cm2) was defined by transesophageal echocardiography in 19 (53%) of 36 patients with suspected thrombus on transthoracic echocardiography in the four-chamber or left ventricular long-axis view. Heavy trabeculation or extremely high echo reflection, or both, was observed in the apical region in 12 patients (33%). No extra structures in the apical region were found in five patients. In 19 patients with transesophageal echocardiographically defined thrombus, 6 patients (31%) experienced arterial embolic events before the transesophageal procedure. In contrast, none of 17 patients without transesophageal echocardiographically defined thrombi had systemic embolism (p < 0.03).Conclusions. 1) Transesophageal echocardiography is useful in identifying left ventricular apical thrombus in patients with unclear echogenic structures on transthoracic apical images; and 2) the high incidence of arterial embolism in patients with transesophageal echocardiographically detected left ventricular thrombus indicates the clinical importance of such thrombus.