Journal of the American Society of Echocardiography - Articles in Press

Changes in Left Ventricular Longitudinal Strain with Anthracycline Chemotherapy in Adolescents Precede Subsequent Decreased Left Ventricular Ejection Fraction - Corrected Proof

2012-05-14

Background: Pediatric cancer survivors who have been exposed to anthracycline (ANT) chemotherapy are an ever increasing population at risk for premature cardiac disease. Studies have shown that ANT is associated with impaired left ventricular (LV) myocardial deformation, but this has not been shown to be associated with traditional echocardiographic measures of LV systolic dysfunction. The aim of this study was to test the hypothesis that changes in LV longitudinal peak systolic strain (LPSS) would correlate with parameters of LV systolic dysfunction.Methods: This study included 19 prospectively enrolled pediatric patients receiving ANT (mean dose, 296 ± 103 mg/m2) and 19 controls matched for age, gender, and body surface area. For ANT patients, echocardiography was performed at baseline, mid, and final treatment points (0, 4, and 8 months). Standard echocardiographic parameters and two-dimensional speckle tracking–derived longitudinal strain parameters were obtained and compared with baseline measurements in controls. Associations between changes in LV global LPSS and standard echocardiographic indices were explored.Results: Within the ANT group, the change in LV global LPSS showed a significant decrease compared with baseline at 4 months (8.7 ± 0.2%, P = .033) and 8 months (9.2 ± 0.3%, P = .015), while the percentage change in ejection fraction (EF) showed a statistically significant decrease at 8 months (4.3 ± 0.1%, P = .044). LV global LPSS was decreased in the ANT group compared with controls at 4 months (18.1 ± 2.5% vs 20.5 ± 1.5%, P = .011) and 8 months (18.1 ± 2.8%, P = .032). Segmental changes in mid and apical LV LPSS average were significantly correlated with change in EF (mid: r = −0.49, β = −0.645, P = 0.039; apical: r = −0.48, β = −0.4126, P = .046).Conclusions: In adolescents who receive ANT therapy, changes in two-dimensional LV global LPSS precede decreases in EF, and segmental changes in mid and apical LV LPSS suggest an increased likelihood that depressed LV EF will be observed later in follow-up. Two-dimensional speckle tracking–derived LV LPSS is potentially useful in the serial clinical monitoring of ANT cardiotoxicity.

Application of 2011 American College of Cardiology Foundation/American Society of Echocardiography Appropriateness Use Criteria in Hospitalized Patients Referred for Transthoracic Echocardiography in a Community Setting - Corrected Proof

2012-05-04

Background: A recent American College of Cardiology Foundation and American Society of Echocardiography document updated previous appropriate use criteria (AUC) for echocardiography. The aim of this study was to explore the application of the new AUC, and the resulting appropriateness rate, in hospitalized patients referred for transthoracic echocardiography (TTE) in a community setting.Methods: A total of 931 consecutive inpatients referred for TTE were prospectively recruited in five community hospitals. Patients were categorized as having appropriate, uncertain, or inappropriate indications for TTE according to the AUC. An additional group of 259 inpatients, discharged without having been referred for TTE, was also considered.Results: In the group referred for TTE, the large majority of indications (98.8%) were classifiable according to the AUC with good interobserver reproducibility. Indications were appropriate in 739 patients (80.3%), of uncertain appropriateness in 46 (5.0%), and inappropriate in 135 (14.7%). Compared with patients with appropriate or uncertain indications, those with inappropriate indications were younger and more often referred by noncardiologists. Most common causes of inappropriate indications were related to the lack of changes in clinical status or to the absence of cardiovascular symptoms and signs. Examinations with appropriate or uncertain indications had an impact on clinical decision making more often than those with inappropriate indications (86.7% vs 14.1%, P < .0001). In the group discharged without having been referred for TTE, TTE might have been appropriate in 16.2% of cases.Conclusions: Clinical application of the new AUC was highly feasible in a community setting. Although inpatient referral for TTE was appropriate in most patients, strategies aimed at implementing these criteria in clinical practice are desirable.

CaRES (Contrast Echocardiography Registry for Safety Surveillance): A Prospective Multicenter Study to Evaluate the Safety of the Ultrasound Contrast Agent Definity in Clinical Practice - Corrected Proof

2012-05-04

Background: Definity (perflutren lipid microsphere) is an ultrasound contrast agent approved for use in patients with suboptimal echocardiograms to opacify the left ventricular chamber and to improve the delineation of the left ventricular endocardial border. This prospective, open-label, nonrandomized, multicenter, phase 4 surveillance registry study was conducted at 15 clinical sites in the United States and was designed to assess the risk for adverse cardiopulmonary events occurring during or within the initial 30 min after Definity administration in routine clinical practice.Methods: Patients with suboptimal baseline images were consecutively approached regarding study participation. Safety monitoring including vital sign measurements, continuous electrocardiographic monitoring, and continuous oxygen saturation was initiated at baseline before Definity administration and then at regular intervals for 30 min after Definity injection. Patients were assessed for adverse events at 30 min after Definity administration and then contacted by telephone at 24 ± 4 hours to record any subsequent adverse events.Results: A total of 1,060 patients were enrolled at 15 clinical sites. Of these, 1,053 (99.3%) received at least one dose of Definity and completed the study. No deaths, serious adverse events, or other significant adverse events occurred during this study. The overall adverse event rate was 10.8% (4.5% in patients undergoing rest echocardiography, 13% in patients undergoing rest and exercise stress echocardiography, and 27.7% in patients undergoing rest and pharmacologic stress echocardiography). The overall drug-related adverse event rate (patients with at least one adverse event reported by the principal investigator as related to Definity) was only 3.5%, and most of these (110 of 114 [96.5%]) were reported by the investigator as mild or moderate in intensity.Conclusions: Definity is well tolerated in routine clinical practice in patients with a high prevalence of cardiopulmonary disease.

Accuracy and Interobserver Concordance of Echocardiographic Assessment of Right Ventricular Size and Systolic Function: A Quality Control Exercise - Corrected Proof

2012-04-30

Background: Accurate assessment of right ventricular (RV) size (RVS) and RV systolic function (RVSF) is vital in the management of various conditions, but their assessment is challenging using echocardiography. The aim of this study was to determine the accuracy and interobserver concordance of qualitative and quantitative RV echocardiography.Methods: Fifteen readers evaluated RV function in 12 patients (360 readings) who underwent echocardiography and cardiac magnetic resonance for RV assessment. Readers qualitatively estimated RVS and RVSF as normal, mild, moderate, or severe and then reassessed quantitatively by adding RV dimensions, fractional area change, S′, tricuspid annular plane systolic excursion, and RV index of myocardial performance. Cardiac magnetic resonance was used as the reference standard for grading RVS and RVSF.Results: Quantitative measurements increased accuracy and interreader agreement compared to qualitative assessment alone, especially in normal categories. Readers’ accuracy for diagnosing normal and severe RVS increased from 38% to 78% (P = .001) and from 70% to 97% (P = .018), and readers’ accuracy for diagnosing normal and mild RVSF increased from 52% to 84% (P < .001) and from 36% to 56% (P = .001). Interreader agreement for classification of the subjects as normal or abnormal improved from a κ value of 0.40 to 0.77 (fair to good agreement) for RVS and from 0.43 to 0.66 (moderate to good agreement) for RVSF.Conclusions: Visual estimation of RVS and RVSF is inaccurate and has wide interobserver variability. Quantitation improves accuracy and reliability, especially in distinction of normal and abnormal. The reliability of mild and moderate grades remains inadequate, and further guidance is needed for the classification of abnormal categories.

Abnormal Cardiac Strain in Children and Young Adults with HIV Acquired in Early Life - Corrected Proof

2012-04-30

Background: Traditional measures of cardiac function are now often normal in adolescents and young adults treated with antiretroviral therapy for human immunodeficiency virus (HIV) infection. There is, however, evidence of myocardial abnormalities in adults with HIV. Cardiac strain analysis may detect impairment in cardiac function that may be missed by conventional measurements in this population.Methods: This was a retrospective study in which echocardiograms of HIV-infected subjects (n = 28) aged 7 to 29 years who participate in a natural history study of HIV acquired early in life were analyzed and compared with matched controls. Standard echocardiographic measures, along with speckle tracking–derived strain and strain rate, were assessed.Results: Among the HIV-infected subjects, the median CD4 count was 667 cells/mm3, and the mean duration of antiretroviral therapy was 14.6 years. Ejection fractions and fractional shortening were normal. There were no significant differences in measures of systolic or diastolic function between the groups. The HIV-infected group had borderline increased left ventricular mass indices. Global longitudinal and circumferential strain and strain rate, as well as global radial strain rate, were significantly impaired in the HIV-infected group compared with controls. There were no associations identified between left ventricular mass index or strain indices and current CD4 count, CD4 nadir, HIV viral load, or duration of antiretroviral therapy.Conclusions: HIV-infected participants demonstrated impaired strain and strain rate despite having normal systolic function and ejection fractions. Strain and strain rate may prove to be prognostic factors for long-term myocardial dysfunction. Therefore, asymptomatic children and young adults with long-standing HIV infection may benefit from these more sensitive measures.

Is a Shorter Atrioventricular Septal Length an Intermediate Phenotype in the Spectrum of Nonsyndromic Atrioventricular Septal Defects? - Corrected Proof

Sonali S. Patel, Larry T. Mahoney, Trudy L. Burns — 2012-04-27

Background: Atrioventricular septal defects (AVSDs) account for 7% of all congenital cardiovascular malformations. The atrioventricular septum (AVS) is the portion of the septal tissue that separates the right atrium from the left ventricle; deficiency of the AVS contributes to the AVSD phenotype. A study of case and control families was performed to identify whether an intermediate phenotype consisting of a shortened AVS existed in relatives of children with AVSDs.Methods: AVS length (AVSL) was measured on the echocardiograms of clinically unaffected parents and siblings from families that were identified through children with nonsyndromic AVSDs and in families with no histories of congenital heart disease.Results: No significant differences were seen between case and control family members in terms of gender, age, weight, and height. AVSLs were significantly shorter in case parents compared with control parents. Similar findings were noted within the sibling groups. There was significant evidence for two-component distributions in the case parent, case sibling, and control sibling groups after standardizing AVSL for age and body surface area. Heritability of AVSL standardized for age and body surface area was 0.82 and 0.71 in nonsyndromic case and control families, respectively.Conclusions: Evidence for two-component distributions from the analysis of AVSL standardized for age and body surface area for case parents and case siblings suggests the presence of an intermediate phenotype for nonsyndromic AVSD. The high heritability in the control families suggests that there may be polygenic involvement in the determination of AVSL. Broadening the definition of AVSD to include those with shortened AVSL may increase the power of genetic association and mapping studies to identify susceptibility genes for AVSD.

Evaluation of Right Ventricular Systolic Function after Mitral Valve Repair: A Two-Dimensional Doppler, Speckle-Tracking, and Three-Dimensional Echocardiographic Study - Corrected Proof

2012-04-27

Background: Conventional indices of right ventricular (RV) function are known to be reduced after cardiac surgery, as a consequence of geometric rather than functional alterations. New techniques, such as three-dimensional (3D) transthoracic and two-dimensional speckle-tracking echocardiography, may be useful in postsurgical RV assessment. The aim of this study was to compare indices of RV function obtained using different echocardiographic modalities, before and after surgery.Methods: Forty-two patients were screened the day before and 6 months after mitral valve repair. Twenty healthy patients were also enrolled as controls. Tricuspid annular plane systolic excursion and peak systolic velocity were calculated from Doppler tissue imaging. Longitudinal and radial strain values were obtained from speckle-tracking echocardiography. RV ejection fraction was calculated from 3D transthoracic echocardiographic RV volumes, and similarly, fractional area change was computed from RV areas.Results: Tricuspid annular plane systolic excursion (25 ± 4 vs 17 ± 3 mm), peak systolic velocity (17 ± 4 vs 12 ± 2 cm/sec), and fractional area change (43 ± 8% vs 39 ± 7%) significantly decreased after surgery (P < .01), while 3D RV ejection fraction was preserved (59 ± 7% vs 59 ± 6%). Speckle-tracking echocardiographic results were dependent on the considered direction, with preserved radial but decreased longitudinal strain values. All postoperative two-dimensional longitudinal indices were smaller than in controls. Preoperative parameters were not significantly correlated with RV functional changes.Conclusions: Although 3D ejection fraction was preserved after surgery, in agreement with the lack of evidence of RV dysfunction, two-dimensional indices showed a functional loss in the longitudinal direction. Fractional area change, as a combination of radial and longitudinal properties, was slightly decreased. Speckle-tracking echocardiography could constitute a useful approach to relate local and space-dependent changes to the global RV function.

Quantification of Mitral Valve Anatomy by Three-Dimensional Transesophageal Echocardiography in Mitral Valve Prolapse Predicts Surgical Anatomy and the Complexity of Mitral Valve Repair - Corrected Proof

2012-04-26

Background: Three-dimensional (3D) transesophageal echocardiography (TEE) is more accurate than two-dimensional (2D) TEE in the qualitative assessment of mitral valve (MV) prolapse (MVP). However, the accuracy of 3D TEE in quantifying MV anatomy is less well studied, and its clinical relevance for MV repair is unknown.Methods: The number of prolapsed segments, leaflet heights, and annular dimensions were assessed using 2D and 3D TEE and compared with surgical measurements in 50 patients (mean age, 61 ± 11 years) who underwent MV repair for mainly advanced MVP.Results: Three-dimensional TEE was more accurate (92%–100%) than 2D TEE (80%–96%) in identifying prolapsed segments. Three-dimensional TEE and intraoperative measurements of leaflet height did not differ significantly, while 2D TEE significantly overestimated the height of the posterior segment P1 and the anterior segment A2. Three-dimensional TEE quantitative MV measurements were related to surgical technique: patients with more complex MVP (one vs two to four vs five or more prolapsed segments) showed progressive enlargement of annular anteroposterior (31 ± 5 vs 34 ± 4 vs 37 ± 6 mm, respectively, P = .02) and commissural diameters (40 ± 6 vs 44 ± 5 vs 50 ± 10 mm, respectively, P = .04) and needed increasingly complex MV repair with larger annuloplasty bands (60 ± 13 vs 67 ± 9 vs 72 ± 10 mm, P = .02) and more neochordae (7 ± 3 vs 12 ± 5 vs 26 ± 6, P < .01).Conclusions: Measurements of MV anatomy on 3D TEE are accurate compared with surgical measurements. Quantitative MV characteristics, as assessed by 3D TEE, determined the complexity of MV repair.

Subclinical Myocardial Dysfunction in Patients with Reverse-Remodeled Dilated Cardiomyopathy - Corrected Proof

2012-04-26

Background: The aim of this study was to test the hypothesis that patients with reverse-remodeled dilated cardiomyopathy (DCM), whose ejection fractions (EFs) were normalized after optimal pharmacologic therapy, had subclinical myocardial dysfunction.Methods: Thirty-two patients with reverse-remodeled DCM, defined as having an initial EF ≤ 35%, which then recovered to ≥50% after optimal pharmacologic therapy, and 11 normal controls with preserved EFs were retrospectively studied. Averaged peak systolic and early diastolic radial, circumferential, and longitudinal speckle-tracking strain rates were assessed from an 18-segment left ventricular model. Similarly, averaged peak systolic radial, circumferential, and longitudinal speckle-tracking strain was obtained.Results: Peak systolic and early diastolic longitudinal strain rates, peak systolic and early diastolic circumferential strain rates, and peak circumferential and longitudinal strain in patients with reverse-remodeled DCM were significantly lower than those in normal controls, but peak systolic and early diastolic radial strain rates and peak radial strain in patients with reverse-remodeled DCM were similar to those in normal controls. Isometric handgrip stress testing showed a significant decrease in EF from 56 ± 5% to 51 ± 5% (P < .001). Of note, the increase of afterload resulting from isometric handgrip stress testing was associated with a decrease in peak systolic circumferential and longitudinal strain rates and peak circumferential strain in patients with reverse-remodeled DCM.Conclusions: The circumferential and longitudinal myocardial function of patients with reverse-remodeled DCM is lower compared with that of normal controls with preserved EFs. Furthermore, the increase in afterload was associated with the decrease in circumferential and longitudinal myocardial systolic function. These findings suggest that in treated patients with DCM with reverse remodeling, left ventricular mechanics may not be normal, even when EFs are normal.

Supine Exercise Echocardiographic Measures of Systolic and Diastolic Function in Children - Corrected Proof

2012-04-23

Background: Echocardiography has been used to determine ventricular function, segmental wall motion abnormality, and pulmonary artery pressure before and after peak exercise. No prior study has investigated systolic and diastolic function using echocardiography at various phases of exercise in children. The aim of this study was to determine the fractional shortening (FS), systolic-to-diastolic (S/D) ratio, heart rate–corrected velocity of circumferential fiber shortening (VCFc), circumferential wall stress (WS), ratio of mitral passive inflow to active inflow (E/A), ratio of passive inflow by pulsed-wave to tissue Doppler (E/E′), and right ventricular–to–right atrial pressure gradient from tricuspid valve regurgitation jet velocity (RVP) and time duration at various phases of exercise in children.Methods: In an 8-month period (December 2007 to July 2008), 100 healthy children were evaluated, and 97 participants aged 8 to 17 years who performed complete cardiopulmonary exercise stress tests using supine cycle ergometry were prospectively enrolled. The participants consisted of 48 female and 49 male subjects with various body sizes, levels of exercise experience, and physical capacities. The cardiopulmonary exercise stress test consisted of baseline pulmonary function testing, continuous gas analysis and monitoring of blood pressure and heart rate responses, electrocardiographic recordings, and oxygen saturation measurement among participants who pedaled against a ramp protocol based on body weight. All participants exercised to exhaustion. Echocardiography was performed during exercise at baseline, at a heart rate of 130 beats/min, at a heart rate of 160 beats/min, at 5 min after exercise, and at 10 min after exercise. FS, S/D ratio, VCFc, WS, E/A, E′, E/E′, and RVP at these five phases were compared in all subjects.Results: All echocardiographic parameters differed at baseline from 160 beats/min (P < .0001) except E/E′, which remained at 5.4 to 5.8. Specifically, FS (from 37% to 46%), S/D ratio, VCFc (from 1.1 to 1.6), WS (from 200 to 258 g/cm2), E′ (from 0.2 to 0.3), and RVP (from 18 to 35 mm Hg) increased from baseline to 160 beats/min and then subsequently decreased to at or near baseline, while tricuspid valve regurgitation duration decreased (from 370 to 178 msec).Conclusions: Normal values for systolic and diastolic echocardiographic measurements of function are now available. FS, VCFc, WS, and RVP increase with exercise and then return to near baseline levels. The E/E′ ratio is unaltered with exercise in normal subjects.

Right Ventricular Longitudinal Peak Systolic Strain Measurements from the Subcostal View in Patients with Suspected Pulmonary Hypertension: A Feasibility Study - Corrected Proof

2012-04-19

Background: The assessment of right ventricular (RV) function with two-dimensional echocardiography can be challenging in patients with pulmonary hypertension, especially in those with chronic pulmonary disease. The aim of the present study was to evaluate the feasibility of measuring RV longitudinal peak systolic strain (LPSS) in the echocardiographic subcostal view in patients with suspected pulmonary hypertension.Methods: A total of 179 patients evaluated for pulmonary hypertension were included (85 with systemic disorder, 64 with pulmonary disease, and 30 with RV dilatation and dysfunction). Additionally, 30 normal controls were evaluated. The feasibility of RV LPSS speckle-tracking measurements in the apical four-chamber view and in the subcostal view was evaluated. Furthermore, the RV LPSS speckle-tracking measurements performed in these two echocardiographic views were compared.Results: The feasibility of RV LPSS in the subcostal view was 95.3%, 92.2%, 93.3%, and 93.3% in patients with systemic disorder, with pulmonary disease, with RV dilatation and dysfunction, and controls, respectively. In comparison, the feasibility of RV LPSS in the apical four-chamber view was 92.9%, 82.8%, 90%, and 93.3% in each group, respectively. Bland-Altman analysis showed good agreement between measurements in both echocardiographic views (systemic disorder: mean bias, −0.14; pulmonary disease: mean bias, 0.28; RV dilatation and dysfunction: mean bias, 0.3; and normal controls: mean bias, −0.14).Conclusions: The subcostal view provides a good alternative for RV strain assessment in patients who are evaluated for pulmonary hypertension. This measurement may be a valuable surrogate of RV function in patients with challenging apical windows.

Altered Central Aortic Elastic Properties in Kawasaki Disease are Related to Changes in Left Ventricular Geometry and Coronary Artery Aneurysm Formation - Corrected Proof

2012-04-12

Background: Recent evidence has suggested that patients display altered arterial elasticity after Kawasaki disease (KD). However, changes in the elastic properties of the central aorta and their relevance to left ventricular geometry have not been studied in patients after KD with and without coronary artery aneurysms (CAAs).Methods: Clinical and laboratory characteristics of 75 patients with KD were compared with those of 57 controls. The patients with KD included 17 patients with CAAs and 58 patients without CAAs. Values for aortic stiffness index, aortic distensibility, aortic strain, and left ventricular mass index (LVMI) were retrospectively obtained from echocardiographic measurements of the ascending aorta and left ventricle with noninvasive blood pressure evaluation.Results: Systolic blood pressure, pulse pressure, LVMI, and aortic stiffness index were significantly higher and aortic distensibility and aortic strain significantly lower in patients with KD than in the controls. In patients with KD, age at the time of study, interval between the onset of KD and the initiation of this study, CAAs, and LVMI were significantly associated with aortic stiffness index, aortic distensibility, and aortic strain. Multivariate analysis revealed that CAAs and LVMI were independently relevant to aortic stiffness index and aortic distensibility.Conclusions: The central aortas of patients after KD have altered elastic properties. CAAs and LVMI are independently correlated with central aortic elasticity.

Noninvasive Estimation of Left Ventricular Compliance Using Three-Dimensional Echocardiography - Corrected Proof

2012-04-02

Background: Left ventricular (LV) compliance is an important determinant of LV function and can be affected by a variety of cardiovascular conditions. In particular, diastolic dysfunction is associated with altered LV compliance. However, the evaluation of LV compliance is complex. Although the end-diastolic pressure-volume relationship (EDPVR) allows a direct, accurate evaluation of LV compliance, it requires invasive measurements. The aim of this study was to test the feasibility of noninvasive estimation of the EDPVR as a tool to evaluate LV compliance using three-dimensional echocardiography.Methods: Sixty-eight subjects were studied, including 23 normal controls, 22 patients with increased LV compliance due to dilated cardiomyopathy, and 23 patients with reduced LV compliance secondary to isolated diastolic dysfunction as defined using current American Society of Echocardiography guidelines. The EDPVR was calculated for each subject using a nonlinear model with echocardiographic estimates of end-diastolic pressure and volume. For both the isolated diastolic dysfunction and dilated cardiomyopathy groups, predicted end-diastolic volumes at predetermined pressure values (5, 10, 20, and 30 mm Hg) were compared with values in normal controls.Results: Compared with controls, noninvasive estimates of the EDPVR resulted in predicted end-diastolic volumes that were lower in the isolated diastolic dysfunction group and higher in the dilated cardiomyopathy group (P < .0001 for all four pressure levels). In addition, a stepwise trend of decreased compliance was noted for the different grades of diastolic dysfunction.Conclusions: This is the first study to demonstrate the feasibility of noninvasive estimation of the LV EDPVR and its ability to differentiate normal from abnormal LV compliance using three-dimensional echocardiography.

Load Independence of Two-Dimensional Speckle-Tracking–Derived Left Ventricular Twist and Apex-to-Base Rotation Delay in Nonischemic Dilated Cardiomyopathy: Implications for Left Ventricular Dyssynchrony Assessment - Corrected Proof

2012-04-01

Background: Left ventricular (LV) twist mechanics are a promising, sensitive tool for assessing pathophysiologic changes in patients with systolic heart failure. Although LV twist is known to be load dependent in healthy volunteers, this has not been examined in patients with “long-standing” dilated cardiomyopathy (DCM). The aim of this study was to determine whether LV twist remains load dependent in the setting of long-standing, nonischemic DCM.Methods: Thirty-four patients with DCM with baseline LV ejection fractions (LVEFs) < 40% and 13 subjects with preserved LVEFs (≥50%) were enrolled. After baseline measurements, pneumatic compression of the lower extremities (Pcom) was used to increase LV afterload. Subsequently, sublingual nitroglycerin (SL-NG) was administered to modify preload. Conventional echocardiographic parameters, LV end-systolic wall stress, net LV twist angle, and apex-to-base-rotation delay (ABRD) were assessed under each condition.Results: In patients with DCM, although LV end-systolic wall stress significantly increased under Pcom (196.9 ± 64.9 g/m2 at baseline vs 231.8 ± 78.9 g/m2 under Pcom, P < .017) and decreased after SL-NG application (231.8 ± 78.9 g/m2 under Pcom vs 197.4 ± 67.4 g/m2 after SL-NG, P < .017), net LV twist angle and ABRD showed no significant changes depending on LV loading condition (for LV twist, 7.63 ± 4.47° at baseline vs 7.03 ± 4.13° under Pcom vs 7.35 ± 4.36° after SL-NG, P = 0.65; for ABRD, 16.56 ± 13.81% at baseline vs 17.19 ± 14.81% under Pcom vs 15.95 ± 13.27% after SL-NG, P = .53). Careful examination of individual patient data revealed that LV twist was load independent when patients had LV twist < 12°. ABRD was also found to be load independent, but only in patients with LVEFs < 34%. In contrast, LV twist and ABRD were load dependent in patients with preserved LVEFs.Conclusions: LV twist and its component, ABRD, had relatively load insensitive properties in patients with long-standing DCM and can be used in future clinical trials as load-independent indexes of LV dyssynchrony.

Transmural Compensation of Myocardial Deformation to Preserve Left Ventricular Ejection Performance in Chronic Aortic Regurgitation - Corrected Proof

2012-03-23

Background: In patients with chronic aortic regurgitation (AR), systolic wall stress and volume overload affects left ventricular (LV) systolic function and remodeling. The aim of this study was to assess transmural rearrangements of myocardial deformation to preserve LV ejection performances using speckle-tracking echocardiography in patients with chronic AR.Methods: Ninety patients with AR were enrolled. On LV short-axis images, total, inner, and outer radial strain and circumferential strain at the inner, mid, and outer layers were calculated. On apical four-chamber images, endocardial longitudinal strain was calculated. End-systolic wall stresses were calculated using previous methods.Results: AR severities were classified as moderate in 31 patients, severe and preserved LV ejection fraction (LVEF) (≥50%) in 42 patients, and severe and reduced LVEF (<50%) in 17 patients. Longitudinal strain was decreased even in the moderate AR group, despite normal end-systolic wall stress. Inner radial strain progressively decreased with increasing end-systolic wall stress, whereas outer radial strain in the moderate and severe AR and preserved LVEF groups was higher than in the control group. Consequently, total radial strain was preserved even in the severe AR and preserved LVEF groups with increased end-systolic wall stress. Similarly, despite reduced inner circumferential strain, outer circumferential strain was higher in the severe AR and preserved LVEF group than in the control group. All strain parameters were lower in the severe AR and reduced LVEF group with dramatically increased end-systolic wall stress than in other groups.Conclusions: Transmural strain analysis revealed that subendocardial dysfunction accompanied by increased wall thickening at the subepicardium may be a compensatory mechanism of wall thickening to preserve LVEF in patients with chronic AR.

Asymptomatic Aortic Stenosis: The Influence of the Systemic Vasculature on Exercise Time - Corrected Proof

2012-03-19

Background: Changes in the peripheral vasculature occur in patients with aortic stenosis (AS). The aims of the present study were to characterize peripheral arterial waveforms and aortic pulsewave velocity (PWV) in patients with AS and to determine their relationship to exercise time.Methods: The study included 101 patients with a median age of 68 years (range, 27–84 years) with at least moderate AS. Patients underwent transthoracic echocardiography, an assessment of the radial artery waveform and PWV using a SphygmoCor device, and a treadmill exercise stress test.Results: The mean brachial systolic blood pressure was 143 ± 23 mm Hg in patients with severe AS and 135 ± 15 mm Hg in patients with moderate AS (P = .04). The mean radial augmentation index was 102 ± 20% in patients with severe AS and 89 ± 16% in those with moderate AS (P < .001). The radial augmentation index was related to the effective valve orifice area (R = −0.45, P = .001), the peak transvalvular pressure difference (R = 0.33, P = .001), and the mean transvalvular pressure difference (R = 0.33, P = .001). On univariate analysis, exercise time was related to systemic arterial compliance (R = 0.312, P = .008) and PWV (R = −0.44, P < 0.001). On multivariate analysis, after adjusting for age, AS severity, and PWV, only age was a significant predictor of exercise time (β = −0.46; P = .006; 95% confidence interval, −15 to −3).Conclusions: In patients with asymptomatic moderate to severe AS, exercise capacity is influenced only by age, not by resting measures of aortic valve stenosis or aortic stiffness.

Flow Characteristics of the SAPIEN Aortic Valve: The Importance of Recognizing In-Stent Flow Acceleration for the Echocardiographic Assessment of Valve Function - Corrected Proof

2012-03-19

Background: The percutaneously implanted Edwards SAPIEN valve (Edwards Lifesciences, Irvine, CA) consists of cusps mounted within a stent. The individual impact of the stent and cusps on transvalvular flow and its implications for the echocardiographic assessment of valve function have not been previously reported.Methods: The study group consisted of 40 patients who underwent successful implantation with the SAPIEN valve. Pulsed Doppler was recorded with sample volumes immediately proximal to the stent (prestent), within the stent but proximal to the cusps (in-stent precusp), and distal to the cusps (in-stent postcusp). The Doppler velocity index and effective orifice area were calculated using both prestent and in-stent precusp velocities to represent “subvalvular” flow and continuous-wave recordings of the left ventricular outflow tract and aortic valve to represent postvalvular flow.Results: In all patients, there was flow acceleration at two levels: in-stent precusp and in-stent postcusp. The mean in-stent precusp peak velocities were significantly higher than the prestent values (1.5 ± 0.2 vs 1.0 ± 0.2 m/sec, P < .0001). Effective orifice area and Doppler velocity index calculated using the prestent versus in-stent precusp velocities were also significantly different (1.79 ± 0.34 vs 2.54 ± 0.46 cm2, P < .0001, and 0.48 ± 0.12 vs 0.73 ± 0.13, P < .0001, respectively).Conclusions: The SAPIEN valve demonstrates flow acceleration at two levels, representing contributions of both the stent and valve cusps to the total valve gradient. Failure to recognize this phenomenon may result in inappropriate selection of the in-stent precusp pulsed Doppler spectrum to represent “subvalvular” flow, thereby overestimating the effective orifice area and Doppler velocity index.

Risk Assessment of Ventricular Arrhythmias in Patients with Nonischemic Dilated Cardiomyopathy by Strain Echocardiography - Corrected Proof

2012-03-15

Background: Indications for prophylactic implantable cardioverter-defibrillator implantation in patients with nonischemic dilated cardiomyopathy (DCM) are based on left ventricular (LV) ejection fraction (LVEF), although LVEF has limited ability to predict arrhythmias. It has recently been shown that strain echocardiography can predict ventricular arrhythmias in patients after myocardial infarction. The aim of this study was to evaluate whether strain echocardiography may help in the risk stratification of ventricular arrhythmias in patients with DCM.Methods: Ninety-four patients with nonischemic DCM were prospectively included. By speckle-tracking strain echocardiography, global longitudinal strain was calculated as the average of peak longitudinal strain from a 16-segment LV model. The time interval from electrocardiographic peak R to peak negative strain was assessed in each LV segment. Mechanical dispersion was defined as the standard deviation of time to peak negative strain from 16 LV segments.Results: After a median of 22 months of follow-up (range, 1–46 months), 12 patients (13%) had experienced arrhythmic events, defined as sustained ventricular tachycardia or cardiac arrest. LVEF and global longitudinal strain were reduced in patients with DCM with arrhythmic events compared with those without (28 ± 10% vs 38 ± 13%, P = .01, and −6.4 ± 3.3% vs −12.3 ± 5.2%, P < .001, respectively). Global longitudinal strain showed greater area under the curve than LVEF to identify arrhythmic events in receiver operating characteristic curve analyses (P = .05). Patients with arrhythmic events had increased mechanical dispersion (98 ± 43 vs 56 ± 18 ms, P < .001). Mechanical dispersion predicted arrhythmias independently of LVEF (hazard ratio, 1.28; 95% confidence interval, 1.11–1.49; P = .001).Conclusions: Global longitudinal strain is a promising marker of arrhythmias. Mechanical dispersion predicted arrhythmic events in patients with DCM independently of LVEF. Strain echocardiography may help in the risk stratification of patients with DCM not fulfilling current implantable cardioverter-defibrillator indications.

Serial Assessment of Right Ventricular Volume and Function in Surgically Palliated Hypoplastic Left Heart Syndrome Using Real-Time Transthoracic Three-Dimensional Echocardiography - Corrected Proof

2012-03-15

Background: Right ventricular (RV) failure is a major cause of morbidity and mortality in patients with hypoplastic left heart syndrome (HLHS), but the longitudinal course of RV volumes through staged palliation (SP) has not been previously investigated. The aim of this study was to evaluate RV volume and function longitudinally through SP of HLHS using real-time three-dimensional echocardiography.Methods: A total of 18 subjects with HLHS were prospectively studied at four time points from diagnosis through stage 2 (SP2). Real-time three-dimensional echocardiographic full-volume data sets were acquired in high–frame rate mode with electrocardiographic gating. Volumetric and functional analyses were performed using a semiautomatic contour detection algorithm. Eighteen age-matched and sex-matched normal infants (aged 0–6 months) were studied at comparable time points as controls.Results: Presurgical examinations (pre–stage 1 [SP1]; n = 18) were performed at a mean age of 4 days, post-SP1 examinations (n = 17) at a mean age of 20 days, pre-SP2 examinations (n = 14) at a mean age of 4.6 months, and post-SP2 examinations (n = 14) at a mean age of 5.5 months, constituting a total of 63 examinations. The mean values of RV end-diastolic volume indexed to body surface area (EDVi) at the four time points were 87 ± 30, 104 ± 39, 112 ± 34, and 102 ± 35 mL/m2, respectively. There was an increase in EDVi (P = .024) from pre-SP1 to post-SP1 but no significant change between post-SP1 and pre-SP2. The decrease in EDVi after SP2 did not reach statistical significance. Mean RV ejection fractions (EFs) were 50 ± 5%, 45 ± 5%, 46 ± 5%, and 38 ± 4%, respectively. There was a trend toward decreasing EF throughout SP, with statistically significant decreases from pre-SP1 to post-SP1 (P = .003) and from pre-SP2 to post-SP2 (P < .001). In normal infants, the mean RV EDVi was 50 ± 10 mL/m2 (approximately half that of patients with HLHS), and the mean EF was 51 ± 3%. There was good interobserver agreement for EDVi, end-systolic volume indexed to body surface area, and EF.Conclusions: Real-time three-dimensional echocardiography is a reproducible means for evaluating RV volumes and EFs in patients with HLHS. Indexed RV diastolic volume remains stable to slightly increased, and RV EF deteriorates as the first two stages of surgical palliation are accomplished. The findings of this study highlight the adverse physiology of HLHS, which deteriorates even among early survivors despite SP.

Two-Dimensional Strain Rate and Doppler Tissue Myocardial Velocities: Analysis by Echocardiography of Hemodynamic and Functional Changes of the Failed Left Ventricle during Different Degrees of Extracorporeal Life Support - Corrected Proof

2012-03-15

Background: To evaluate hemodynamic and functional changes of the failed left ventricle by Velocity Vector Imaging (VVI) and tissue Doppler, 22 patients with cardiogenic shock supported by extracorporeal life support (ECLS) were imaged during ECLS output variations inducing severe load manipulations.Methods: The following data were acquired: (1) mean arterial pressure, aortic Doppler velocity-time integral, left ventricular end-diastolic volume, and mitral Doppler E wave; (2) tissue Doppler systolic (Sa) and early diastolic (Ea) velocities; and (3) systolic peak velocity (Sv), strain, and strain rate using VVI.Results: Load variations were documented by a significant decrease in afterload (mean arterial pressure, −21%), an increase in preload (left ventricular end-diastolic volume, +12%; E, +46%; E/Ea ratio, +22%), and an increase in the velocity-time integral (+45%). VVI parameters increased (Sv, +36%; strain, +81%; and strain rate, +67%; P < .05), unlike tissue Doppler systolic velocities (+2%; P = NS). Whatever the ECLS flow, Sa was higher in patients who survived.Conclusions: VVI parameters are not useful in characterizing the failed left ventricle with rapidly varying load conditions. Tissue Doppler systolic velocities appear to be load independent and thus could help in the management of ECLS patients.

Global Left Ventricular Longitudinal Systolic Strain for Early Risk Assessment in Patients with Acute Myocardial Infarction Treated with Primary Percutaneous Intervention - Corrected Proof

2012-03-12

Background: Left ventricular systolic function is a key determinant of outcome after ST-segment elevation myocardial infarction (STEMI). The aim of this study was to study speckle-tracking global longitudinal strain (GLS) for early risk evaluation in STEMI and compare it with left ventricular ejection fraction (LVEF), wall motion score index (WMSI), and end-systolic volume index (ESVI).Methods: Five-hundred seventy-six patients underwent echocardiography ≤24 hours after primary percutaneous coronary intervention for STEMI. The end point was the composite of death, hospitalization with reinfarction, congestive heart failure, or stroke. Associations with outcome were assessed by multivariate Cox regression with adjustment for clinical parameters. Hazard ratios (HRs) for events within the first year are reported per absolute percentage GLS increase.Results: During a median follow-up period of 24 months, 162 patients experienced at least one event. GLS was associated with the composite end point (adjusted HR, 1.20; 95% confidence interval [CI], 1.12–1.29) and also when controlling for LVEF (adjusted HR, 1.17; 95% CI, 1.07–1.29) and ESVI (adjusted HR, 1.18; 95% CI, 1.08–1.28). Although WMSI was significantly associated with outcome beyond any association accounted for by GLS, a borderline significant association was found after controlling for WMSI (adjusted HR for GLS, 1.10; 95% CI, 1.00–1.21). When GLS or WMSI was known, there was no significant association between LVEF or ESVI and outcome.Conclusions: In a large population of patients with STEMI, GLS and WMSI were comparable and both superior for early risk assessment compared with volume-based left ventricular function indicators such as LVEF and ESVI. Compared with WMSI, the advantage of GLS is the provision of a semiautomated quantitative measure.

The Dominant Vein in the Infraclavicular Fossa Is the Axillary Vein, Not the Subclavian - Corrected Proof

Jack LeDonne — 2012-02-27

I would like to discuss a few points raised by Troianos et al. in their recent thoughtful, well-researched report on ultrasound-guided vascular cannulation in JASE. First, on page 1294, Troianos et al. state, “A limitation of the needle guide is that the needle trajectory is limited to orthogonal orientations from the SAX [short-axis] imaging plane.” However, needle guides oriented to the long axis are in fact commercially available (see ).