Short-axis Projection Research Articles

A learning-based, region of interest-tracking algorithm for catheter detection in echocardiography.

Echocardiography (echo) is gaining popularity to guide the catheter during surgical procedures. However, it is difficult to discern the catheter tip in echo even with an acoustically active catheter. An acoustically active catheter is detected for the first time in cardiac echo images using two methods. First, a convolutional neural network (CNN) model was trained to detect the region of interest (ROI), the interior of the left ventricle, containing the catheter tip. Color intensity difference detection technique was implemented on the ROI to detect the catheter. This method succeeded in detecting the catheter without any manual input on 94% and 57% of long- and short-axis projections, respectively. Second, several tracking methods were implemented and tested. Given the manually identified initial positions of the catheter, the tracking methods could distinguish between the target (catheter tip) and the surrounding on the rest of the frames. Combining the two techniques, for the first time, resulted in an automatic, robust, and fast method for catheter detection in echo images.

401 Myocardial viability and ischaemia assessment in chronic coronary total occlusions according to collaterals distribution: a retrospective analysis

Abstract Aims Whether CTO-PCI (chronic total occlusions—percutaneous coronary intervention) offers clinical benefit over optimal medical therapy is still a matter of debate. Viability and ischaemia assessment could improve selection of candidates to PCI. Traditionally, well-developed collaterals are considered a marker of myocardial viability in CTO territory. Current literature offers few data concerning the relationship between viability/ischaemia and collaterals distribution. Methods and results We retrospectively analysed the Cardiovascular Magnetic Resonance (CMR) studies and coronary angiographies of patients with at least one CTO referred at Humanitas Research Hospital between June 2009 and September 2020. We included 131 patients who underwent CMR with LGE assessment; of them, 111 (85%) underwent stress-CMR with adenosine. AHA segments (16 segment/patient for a total of 2096 segment assessed) were assessed on three short axis projection and scored for WMSI on cine images, for the presence of ischaemia on first pass perfusion, and for viability on LGE images. Viability was defined as LGE transmurality ≤50% and WMSI (wall motion score index) >1. Patients were divided in three groups according to collaterals distribution at coronary angiography: Patients with TD collaterals were more likely to have viable segments in the CTO-territory (90% of the segments in TD, 76% in WD, and 71% in PD, coeff. 0.107, P < 0.001). No statistically significant differences were found between groups as regard the amount of ischaemic segments (61% of the segments in TD, 65% in WD, and 60% in PD, P = 0.189). Conclusions The presence of myocardial viability is slightly associated with the degree of coronary collateralization at coronary angiography while the amount of ischaemia is not. Stress CMR should be considered in CTO patients before a reopening attempt.

Quantitative assessment of myocardial scar heterogeneity using cardiovascular magnetic resonance texture analysis to risk stratify patients post-myocardial infarction

To determine whether heterogeneity of cardiac scar, as assessed by cardiovascular magnetic resonance (CMR) texture analysis, may provide insight into better risk stratification for patients with previous myocardial infarction (MI). Patients with previous MI (n=76) were followed for a median of 371.5 days after late gadolinium enhancement (LGE) CMR. The primary endpoint was a composite of ventricular tachycardia, ventricular fibrillation, or unexplained syncope. Areas of LGE were identified and manually segmented on a short-axis projection. The characteristics of the scar heterogeneity were evaluated via CMR texture analysis. This is a filtration-histogram technique, where images are filtered using the Laplacian of a Gaussian filter to extract features different sizes (2-6 mm in radius) corresponding to fine, medium, and coarse texture scales followed by a quantification step using histogram analysis (skewness and kurtosis). Patients suffering arrhythmic events during the follow-up period demonstrated significantly higher kurtosis (coarse-scale, p=0.005) and lower skewness (fine-scale, p=0.046) compared to those suffering no arrhythmic events. Furthermore, Kaplan-Meier analysis showed significantly higher coarse kurtosis (p=0.004), and lower fine skewness (p=0.035) were able to predict increased incidence of ventricular arrhythmic events. In this pilot study, indices of texture analysis reflecting textural heterogeneity were significantly associated with a greater incidence of arrhythmic events. Further work is required to delineate the role of texture analysis techniques in risk stratification post-MI.

Abstract 17186: Regional Extracellular Volume Fraction Can Identify Cardiac Muscle Changes in Patients With Duchenne Muscular Dystrophy

Background: Duchenne muscular dystrophy (DMD) is an X-linked inherited disorder causing dilated cardiomyopathy with variable onset and progression. Our aim was to compare native T1 mapping and extracellular volume fraction (ECV) in boys with DMD to controls to identify markers of preclinical myocardial disease. Methods: With IRB approval and informed consent/assent, 17 boys with DMD had cardiac magnetic resonance imaging (MRI) with contrast. Ejection fraction (EF), presence of late gadolinium enhancement (LGE), native T1, and ECV mapping were obtained using a modified Look-Locker sequence on a 1.5T MR scanner (Figure 1). Results were compared with age and gender matched controls with no history predisposing to cardiac fibrosis (i.e. bypass, myocarditis, etc). Results: Seventeen DMD subjects (age 14 ± 5 years; EF 56% ± 8%) were compared with 13 normal controls (age 17 ± 4 years) with normal EF and no LGE. DMD subjects had low-normal EF (average EF 56% ± 8%) and 10 of 17 (59%) had evidence of LGE, all in the lateral location. Comparing native T1 in DMD vs controls, septal native T1 was 1060 ± 71 ms versus 990 ± 34 ms (p < 0.01) and lateral native T1 was 1090 ± 93 versus 978 ± 37 ms, respectively (p < 0.01). Comparing ECV values in DMD vs controls, septal ECV was 29.6 ± 7.8 and 25.9 ± 3.4 (p = 0.03) and lateral ECV was 32.7 ± 8.7 and 24.4 ±3.6 (p < 0.01), respectively. All DMD patients with abnormal EF and/or presence of LGE also had higher ECV values. Conclusions: ECV is strongly-related to DMD and differs significantly compared to normals, particularly in the lateral wall. ECV mapping may be a useful technique for identifying preclinical myocardial changes in DMD. Figure 1. A) Precontrast T1 map, B) post contrast T1 map and C) ECV map with scale on the right in the short axis projection of a boy with Duchenne muscular dystrophy. Arrows indicate elevated values laterally.

Experimental Study of Kinematic Activity of Left Ventricular Myocardium.

A method of invasive and non-invasive examination of epicardial motion was tested on domestic pigs (n=15). The invasive study employed a contact kinematic sensor of the epicardial wall motion, which determined the amplitude, velocity, and angular parameters of examined epicardial region. A non-invasive assessment of the epicardial kinematics based on echocardiographic 2D Velocity Vector Imaging and ECG recoding used to determine the heart electrical axis. The 4-chamber views were uses to analyze the longitudinal displacements of lateral wall of the left ventricle at the basal, mid, and apical segments. In addition, the radial displacements were determined in short axis projections at basal and apical segments as well as at the level of papillary muscles. The animals with normal or horizontal heart's electrical axis demonstrated similar displacement of the epicardium along X-axis and in longitudinal direction, while displacement along Y-axis corresponded to that in radial direction. The combined invasive and non-invasive approach in measurement of epicardium motion makes it possible to quantify the kinematic epicardial activity.

Common two-dimensional echocardiographic estimates of aortic linear dimensions are interchangeable

ObjectiveTo compare two echocardiographic methods of measuring aortic diameter in short-axis projections. MethodsRight-parasternal short-axis 2-dimensional projections of the left atrium and aorta were obtained from dogs and cats undergoing routine cardiac evaluation. Two investigators measured the aortic valve linear dimension using 2 methods: along the commissure between the non-coronary and right-coronary cusps and along the commissure between the non-coronary and left-coronary cusps. Inter-observer and intra-observer variability and agreement were assessed by comparing blinded measurements with each method by 4 trained observers on a standardized set of images. Measurements were compared for agreement using the limits of agreement analysis. Variability between observers was compared by examining residuals and intraclass correlation. Results274 canine and 100 feline aortic valve images were measured in the first part of the study. One observer demonstrated slight proportional bias, while the other observer showed more variability (less agreement). When results were pooled for both investigators, no bias was identified, and 95% limits of agreement were ±10% of the mean measurement for both species. In the second part of the study, 106 images were measured. Intraobserver variability was <4% for all observers. Inter-observer agreement was very high. Individual bias was identified in some observers, but was considered clinically inconsequential. Normalized differences between the 2 methods of measurement were below ±15% of the measured value for all observers. ConclusionsOur results show sufficient agreement between two common methods used to measure aortic linear dimensions to suggest that these methods are interchangeable.

1081Constrictive Pericarditis in the Modern Cardiology Era Quantitative Analysis of Constrictive Physiology using Four-Dimensional MRI

Objectives: Accurate diagnosis of constrictive pericarditis (CP) is a well-recognized clinical challenge. Since magnetic resonance imaging (MRI) provides high resolution assessment of ventricular volumes, we sought to investigate left ventricular (LV) and right ventricular (RV) time-volume curve using four-dimensional MRI (4D MRI) in patients with CP. Methods: Fourteen patients with CP who had undergone surgery for pericardiectomy and 10 normal subjects were included. Three dimensional MRI covering the whole myocardium in the short axis projection was performed. LV and RV volumes were evaluated over the whole cardiac cycle to generate a four-dimensional MRI dataset for assessment of ventricular time volume curve yielding systolic function and filling parameters: end-diastolic and end-systolic volume, ejection fraction, filling time, early and late filling volume, E/A ratio, peak filling rate (PFR), and time to peak filling rate (TPFR). Results: In patients compared with normal subjects, LV and RV end-diastolic and end-systolic volumes were decreased (all P < 0.05), but biventricular ejection fraction was similar. The filling time of both ventricles was significantly shorter (both P < 0.001). In early diastole, LV and RV filling volumes were increased (P = 0.004, P < 0.001; respectively), in late diastole; however, LV and RV filling volumes were reduced (both P < 0.001). Biventricular E/A ratio and PFR were higher (all P < 0.001) and TPFR of the right ventricle was lower (P = 0.02) in patients compared with normal subjects. Conclusion: In patients with CP quantitative 4D MRI analysis provides reduction in end-diastolic and end-systolic volumes and demonstrated a typical hemodynamic response. In early diastole both ventricles have an increased filling, in late diastole, however; the constricted physiology allowed only a slight ventricular filling.

Novel Simple Approach for Detection of Regional Perturbations of Cardiac Function in Mouse Models of Cardiovascular Disease

Transthoracic murine echocardiography is a cornerstone of small animal research, but conventional methods cannot detect regional perturbations in cardiac function. Reliable assessment of regional cardiac function would be of value in transgenic models of myocardial disease. Until now automatized algorithms for achieving this suffers from a number of drawbacks. We developed a simple algorithm for rapidly assessing the relative myocardial radial thickening that occurs between end-diastole and end-systole, that is, regional radial transmural end-systolic strain (RTESS). Echocardiographic assessment was performed in mice at baseline (n = 8), 2 hours postintraperitoneal isoprenaline (ISO) injection (n = 8), and 10 days postmyocardial infarction (post-MI) (n = 6). A >1000 frames/sec cine loop was acquired by the ECG-gated Kilohertz visualization technique in the parasternal short-axis projection at 3 mm below the mitral annulus. Endo- and epicardial borders were traced at end-diastole and end-systole and RTESS was calculated for each of n segments by the algorithm. The intra- and inter-observer coefficients of variation for segmental RTESS assessment were 5.11 and 7.32, respectively. At baseline, average segmental RTESS was 56.75% and RTESS was similar in all cardiac segments regardless of how many segments the heart was divided into. In the akinetic myocardium of MI and ISO mice, 47.36% and 26.22% length of the endocardium, respectively, RTESS was near zero and significantly different from the remaining myocardium. We describe a simple and straightforward approach to quantify regional myocardial deformation in mouse models of cardiovascular disease.

Early identification of trastuzumab-related cardiotoxicity with speckle-tracking echocardiography.

e11096 Background: New targeted therapies have improved the prognosis of patients with breast cancer but cause several off-target effects, such as left ventricular dysfunction and heart failure that has still a 5-years mortality of 50%. Adjuvant treatment of breast cancer consists of combination chemotherapy with anthracyclines (A) and, in women with ErbB2 over-expressing disease, trastuzumab (T). A can cause an irreversible left ventricular dysfunction, named type I cardiomyopathy. T causes can cause left ventricular systolic dysfunction between 3% and 18%, and heart failure between 2% and 4%, but these are reversible and there seems to be no apparent ultrastructural changes (II type cardiomyopathy). Methods for measuring cardiac function in M-mode with shortening fraction (FA) and in B-mode with ejection fraction are not very sensitive in detecting early myocardial damage. The aim of this study was to evaluate if myocardial strain by speckle tracking technique (ST) was able to identify early left ventricular dysfunction in mice treated with doxorubicin (D) and T, alone or in combination (D+T). Methods: We measured radial myocardial strain (%) with ST and FA by assessing M-mode short axis projection in C57BL/6 mice at time 0, 2 and 6 days of daily administration of D (2.17 μg/g/day), T (2.25 μg/g/day), D + T (2.17 μg/g/day + 2.25 μg/g/day, respectively), and in a control group. Results: The second day we found a significant reduction of radial strain in the group D (p = 0.003), T (p = 0.03) and D+T (p = 0.003). The FA was reduced significantly on day 2 only in group D (p < 0.001) and D+T (p = 0.001), whereas in group T was normal, and decreased only at day 6 (p = 0.001). Conclusions: With myocardial strain obtained with ST technique it is possible to identify left ventricular systolic dysfunction early, before conventional echocardiography. The reason why this was found only in T group probably lies in the fact that T does not cause myocardial necrosis, in contrast to A, but reversible alterations (harder to detect early with the reduced FA). These studies will be extended to patients, to evaluate the clinical impact of early identification of T-related cardiotoxicity in the treatment of women affected by breast cancer. No significant financial relationships to disclose.

Cardiotoxic effects, or lack thereof, of anti-ErbB2 immunoagents.

e11054 Background: Herceptin (H), an anti-ErbB2 humanized antibody prescribed for treatment of ErbB2-positive breast cancer, has proved to be an essential tool in immunotherapy. However, large-scale clinical studies with H have shown that it engenders cardiomyopathy, particularly in patients treated either concurrently or previously with anthracyclines. Two novel human antitumor immunoconjugates were engineered in our laboratory by fusion of a human anti-ErbB2 scFv, Erbicin, with either a human RNase or the Fc region of a human IgG1, and thus called Erb- hRNase and Erb-hcAb (human anti-ErbB2-compact antibody), respectively. Both immunoagents are selectively cytotoxic for ErbB2-positive cancer cells in vitro and vivo. The Erbicin-derived immunoagents (EDIA) target on breast cancer cells an ErbB2 epitope different from that of H. We report that EDIA did not show in vitro cardiotoxic effects on rat and human cardiomyocytes, whereas H was strongly toxic. Methods: Methods for measuring cardiac function in M-mode with shortening fraction (FA) and in B-mode with ejection fraction are not very sensitive in detecting early myocardial damage. In this study we evaluated myocardial strain by speckle tracking technique (ST) by Color Doppler echocardiography (Visual sonic Vevo 2100) to identify early left ventricular dysfunction in mice treated with EDIA, doxorubicin (D), H, their associations and in a sham group. We measured ST and FA by assessing M-mode short axis projection in C57BL/6 mice at time 0, 2 and 6 days of daily administration. Results: EDIA did not impair cardiac function in vivo in a mouse model whereas H significantly reduced radial strain at 3 days of treatment and fractional shortening (% FS) at 6 days of treatment compared to the sham group in a fashion similar to D. Similarly, cardiac fibrosis, an index of collagen accumulation following cardiac muscle deterioration, was significantly attenuated in mice treated with either Erb-hcAb or Erb-hRNase as compared to those treated with H or D. Conclusions: These results suggest that the Erb-hcAb and the immuno RNase are immunoagents which can fulfil the therapeutic need of patients ineligible to H treatment due to cardiac dysfunction. No significant financial relationships to disclose.

Rare case of double inlet left ventricle: Functional and anatomic information provided by adenosine Tc-99m sestamibi SPECT

Advances in cardiovascular care and cardiothoracic surgical expertise have enabled many patients with congenital heart disease to live well into adulthood. With lengthened life expectancies, congenital heart disease patients are more frequently undergoing noninvasive nuclear cardiac imaging to exclude perfusion abnormalities. We present the Tc-99m sestamibi SPECT findings of a patient with an uncommon congenital malformation. Case history. A 45-year-old man with doubleinlet left ventricle, pulmonary stenosis, pulmonary hypertension, status postmultiple systemic-pulmonary shunt procedures, and, most recently, a Potts anastamosis (descending aorta to the left pulmonary artery anastamosis) at age 31, presented to the cardiology clinic complaining of burning epigastric pain on exertion. The patient had known pulmonary artery hypertension but had improved his oxygen saturation and exercise tolerance on a regimen of bosentan, coumadin, digoxin, and verapamil. Initially, the patient underwent a modified walk test and was able to walk on a level surface at increasing speed for 15 minutes, achieving a peak speed of 1.8 miles per hour, HR 97, BP 148/69, when he complained of progressive chest burning. His pulse oximetry at rest was 84% and dropped to 72% with exercise. The electrocardiogram showed no change from baseline (sinus rhythm, left ventricular hypertrophy with strain, and ST elevation in the right precordial leads). In light of the reproducible symptoms and the patient’s strong preference for noninvasive evaluation, he underwent adenosine Tc-99m sestamibi SPECT to evaluate for coronary artery disease. The patient was infused with 140 mcg per kilogram per minute of adenosine over a 6-minute period; at 3 minutes into the infusion, 99mTc sestamibi was injected. There were no reported electrocardiogram changes or symptoms during adenosine infusion. Images were acquired with 180° SPECT approximately 30 minutes later. Findings. The adenosine sestamibi SPECT images showed a large left-ventricle cavity with no definite myocardial perfusion abnormality. Low counts were seen along the middle inferior wall because of adjacent tracer activity in a loop of small bowel. On both stress and rest images, the short-axis projection showed a smaller, rounded structure with a central lumen from the middle anterior to basal ventricular cavity, consistent with a rudimentary right ventricle (Figure 1). Because this is essentially a single functioning chamber, absent were the typical-appearing interventricular septum or right ventricle (compare with the normal right ventricle and septum in Figure 2). Despite the unusual anatomy, the gated SPECT perfusion images showed normal left ventricular myocardial wall motion and systolic thickening with an ejection fraction of 51%. The cardiac chambers were further clarified by viewing the patient’s transesophageal echocardiogram to evaluate mitral insufficiency (Figures 3 and 4).

Atresia bilateral de venas pulmonares

Rev Esp Cardiol 2002;55(6):671-2 671 Congenital atresia of the pulmonary veins is a rare anomaly that is not associated with other heart disease. It has a poor prognosis and patients die secondary to pulmonary hypertension, recurrent hemoptysis, pulmonary edema, or congestive cardiac insufficiency. We present a 5-year-old male patient admitted to the hospital for asthenia, anorexia, hemoptoic vomiting, and a severe cough. Marked dystrophy was observed, with a weight of less than the 3rd percentile, pale skin and mucous, and bilateral nystagmus. Cardiovascular examination did not reveal murmurs and the second heart sound was strong. With respect to echocardiogram data, on 4-chamber projection the connections of the left pulmonary veins and the right superior vein lobe to the left atrium were not seen; in the short axis projection the great vessels were in a normal relationship, with the diameter of the pulmonary artery being greater than the diameter of the ascending aorta, the IM AG E S I N C A R D I O L O G Y

Straddling tricuspid valve as a sign of ventriculoatrial malalignment: A morphometric study of 19 postmortem cases

Background Straddling tricuspid valve, despite extensive investigation, remains an incompletely understood form of complex congenital heart disease. Methods A morphometric study of 19 postmortem cases of straddling tricuspid valve was performed, and the results were compared with 32 normal control heart specimens. Results In straddling tricuspid valve, marked malalignment of the ventricles was always found relative to the atria. The angle between the ventricular septum and the atrial septum in the short-axis projection averaged 61° ± 24°, the normal ventriculoatrial septal angle averaging 5° ± 2° ( P < .001). The right ventricular sinus (inflow tract) was significantly smaller than the left ( P < .01). A ventricular septal defect was present in 79%: atrioventricular canal type in 42%, atrioventricular canal type confluent with a conoventricular defect in 26%, and a conoventricular defect in 11%. When the straddling tricuspid valve adhered to the crest of the muscular ventricular septum (n = 4 cases, 21%), the 2 salient findings were (1) an intact ventricular septum and (2) double-outlet right atrium. The nonstraddling part of the tricuspid valve opened into the small right ventricle. The straddling part of the tricuspid valve opened into the larger left ventricle. The mitral valve also opened into the left ventricle. Hence hearts with double-outlet right atrium had 3 atrioventricular valves. Congenital mitral stenosis was present in 26% of this series. Conclusion Straddling tricuspid valve was always characterized by marked ventriculoatrial malalignment, indicated by an abnormally large ventriculoatrial septal angle, best seen in the short-axis projection. (Am Heart J 1999;138:1184-95.)

Prevalence of Carotid Kinking and Coiling in a Population at Risk

The prevalence of carotid kinking and coiling in patients with hypertension or diabetes was investigated. The authors studied three groups: 130 subjects with hypertension, 105 with diabetes, and 50 normal subjects who were comparable for age, sex distribution, and the presence of other risk factors. Color flow ultrasonography of the extracranial carotid arteries was performed by standard technique. Hard-copy photographs were obtained in three long-axis and three short-axis projections. The prevalence of carotid kinking and coiling was significantly higher in the group of hypertensive patients than in diabetics and normal subjects (14.6% vs 2% and 14.6% vs 4%, respectively; P &lt; 0.01 for both compar isons). The prevalence of carotid kinking was associated with the duration of hyperten sion, whereas it did not show any association with cigarette smoking and serum choles terol levels. A long-term observation of these patients is necessary for determining the natural history of carotid kinking and the potential for modification by adequate antihy pertensive therapy. The results of this study show that a significantly higher prevalence of carotid kinking is present in hypertensive patients in comparison with normal subjects and diabetics and this is correlated with the time of onset of hypertension.

Comparison of electron beam computed tomography scanning and magnetic resonance imaging quantification of right ventricular mass: Validation with autopsy weights

We compared, in the same human hearts, the ability of magnetic resonance (MR) imaging and electron beam computed tomography (CT) scanning to accurately quantify the free wall and septal components of right ventricular (RV) mass. Eleven hearts extracted at autopsy were subjected to MR imaging and electron beam CT scanning in short-axis projections. Regression analyses of mass determinations obtained by manual planimetry MR imaging and electron beam CT scanning and autopsy weights were performed. RV free wall mass by both MR imaging (53.4 +/- 19.1 g) and electron beam CT scanning (53.9 +/- 20.4 g) correlated well with autopsy weight (57.7 +/- 20.2 g). Regression analysis showed a strong correlation for MR imaging (r = .88, slope = .88, standard error the estimate [SEE] = 7.2 g, p < .001) and electron beam CT scanning (r = .95, slope = .95, SEE = 6.6 g, p < .001). RV septal mass by MR imaging (10.8 +/- 3.5 g) and electron beam CT scanning (7.1 +/- 2.4 g) correlated less well with the autopsy weight (12.5 +/- 6.5 g). Regression analysis showed a fair correlation for MR imaging (r = .45, slope = .83, SEE = 2.05 g, p = .001) and a poor correlation for electron beam CT scanning (r = .46, slope = .17, SEE = 2.25 g, p = .57). Both MR imaging and electron beam CT scanning accurately predict RV free wall mass but have difficulty predicting the septal component. Because the septal component constitutes only a small proportion of the total RV mass, determinations of RV mass should be based solely on the free wall component.

Right ventricular mass measurement by electron beam computed tomography. Validation with autopsy data.

Validation of right ventricular mass quantitation by electron beam computed tomography in humans has not been performed. The ability of electron beam computed tomography to accurately determine the septal component of the right ventricle also has not been determined. This article addresses both issues. Twenty human adult hearts obtained at autopsy were scanned by electron beam computed tomography in a short-axis projection. Planimetry of the right ventricular free wall and septal components of each slice was performed and summed to determine right ventricular mass. These measurements were compared against comparable measurements obtained by autopsy weights of the hearts. Right ventricular free wall weights by electron beam computed tomography (53.9 +/- 18.4 g) correlated well (slope = .92, r = .92, standard error of the estimate = 7.4 g, P < .001) with autopsy weights (55.8 +/- 18.4 g). Right ventricular septal weights by electron beam computed tomography (6.1 +/- 2.3 g) correlated poorly (slope = .04, r = .11, standard error of the estimate = 2.4 g, P = .65) with autopsy weights (13.9 +/- 6.3 g). Electron beam computed tomography quantitation of right ventricular mass is accurate in humans if only the free wall and not the septal component is utilized.

Transvaginal fetal echocardiography in early pregnancy: Normative data

Fifty-two transvaginal ultrasonographic examinations were performed between 10.0 and 14.9 weeks' gestation for the purpose of documenting normal fetal cardiac anatomy. All standard cardiac projections could be obtained by gestational week 12, and many were imaged by week 11. The four-chamber view was visualized in 90% of fetuses at 12 weeks' gestation and in 100% of fetuses examined at 13 weeks. The aortic root in short axis projection and the left ventricle in long axis view could be imaged in 70% and 40% of fetuses, respectively, by 12 weeks' gestation. Aortic and pulmonary valves were first visualized at 12 weeks, as were five-chamber, ductus arteriosus, and aortic arch views. The mitral and tricuspid valves were resolved in 60% of fetuses by 11 weeks' gestation. This study of normal cardiac anatomy suggests that there may be significant potential for the diagnosis of many fetal cardiac anomalies during the late first and early second trimesters of pregnancy.

Interventricular septal motion and left ventricular function in patients with atrial septal defect.

In order to assess whether the paradoxical motion of the interventricular septum seen in patients with atrial septal defect (ASD) is due to a true abnormality in septal contraction, eight patients with ASD (age, 1.6-17 years) and eight age-matched control patients were studied using qualitative and quantitative two-dimensional (2D) and M-mode echocardiography. 2-D-echocardiographic images recorded from the parasternal short-axis projection at the level of the papillary muscles and 2D-directed M-mode tracings at this level were obtained. Comprehensive wall motion analysis of the left ventricular (LV) endocardial and epicardial borders was performed using both fixed reference and center of mass (floating reference) models. Our results indicate that interventricular septal wall motion and function are normal in patients with ASD. The apparent "paradoxical" motion is due to excessive anterior motion of the entire left ventricle, and is present only when a fixed reference system is used to assess myocardial motion, but is not present when a center of mass (floating reference system) is employed. Left ventricular function assessed by % area and perimeter change, mean radial shortening fraction, and mean radial wall thickening (2D) as well as LV shortening fraction and septal and posterior wall thickening (M-mode) was not significantly different between the two groups. Standard M-mode tracings can therefore be used to assess LV function despite this apparent abnormal septal motion.

Validation of quantitative intraoperative transesophageal echocardiography.

Transesophageal echocardiography (TEE) is a new monitoring technique that images the heart and provides information on regional wall motion and left ventricular filling. However, despite its potential for inaccuracy due to its retrocardiac position and angulation, TEE has not been validated by another imaging technique. Using direct on-heart echocardiography (OHE) as a standard, the authors evaluated the ability of TEE to measure accurately left ventricular end-diastolic area (EDa), end-systolic area (ESa), and ejection fraction area (EFa). Ten patients with coronary artery disease without evidence of valvular dysfunction undergoing myocardial revascularization were studied. A Diasonics 3.5 MHz two-dimensional TEE probe was introduced into each patient's esophagus and positioned to obtain a view equivalent to the parasternal short-axis projection. A similar view was obtained by OHE using a sterilely prepared 3 MHz ATL probe placed on either the pericardium or epicardium. In each patient, immediately prior to and after pericardiotomy, both transesophageal and on-heart short-axis views at the level of the papillary muscles were obtained. Using a dedicated Diasonics computer echoanalyzer, EDa and ESa from four consecutive cardiac cycles were outlined with a light pen and averaged. EFa was calculated by the formula EFa = (EDa - ESa)/EDa. Seventeen comparable transesophageal and on-heart echocardiograms were obtained. ESa by TEE correlated well with ESa by OHE (15.13 +/- 9.62 cm2 vs. 14.92 +/- 10.53 cm2; r = 0.94). Similar results were obtained for EDa (27.75 +/- 9.88 cm2 vs. 30.40 +/- 13.99 cm2; r = 0.88) and EFa (0.49 +/- 0.17 vs. 0.54 +/- 0.13; r = 0.92). filling and ejection.

Serial assessment of circumferential regional left ventricular function following complete coronary occlusion

The effect of abrupt coronary artery occlusion on regional left ventricular (LV) function is well known, but serial changes in circumferential regional function over the first few hours have not been extensively investigated. Circumflex coronary artery occlusion was produced in nine closed-chest, conscious dogs and changes in LV circumferential function were assessed using two-dimensional echocardiography (2DE) performed in the short-axis projection at the mid-papillary muscle level. End-diastolic and end-systolic frames were manually digitized and regional area ejection fractions at 22.5-degree intervals were calculated using a fixed diastolic center of mass. Endocardial motion abnormality was measured from a circumferential regional ejection fraction map. The extent of wall motion abnormality was measured as that exceeding 95% confidence limits of normal controls; the degree of dyssynergy was measured as the planimetered area of the extent of wall motion abnormality. Following circumflex coronary artery occlusion, a wall motion abnormality was well defined with a minute of occlusion and its circumferential extent measured 146 ± 16 degrees with 11 ± 2 cm 2 absolute degree of dyssynergy. These parameters did not change over the course of the coronary artery occlusion. We conclude that circumferential regional abnormalities produced by coronary occlusions are well defined early and do not change over the first 3 hours of acute ischemia and infarction.