Added Value of 3- Versus 2-Dimensional Echocardiography Left Ventricular Ejection Fraction to Predict Arrhythmic Risk in Patients With Left Ventricular Dysfunction.

OBJECTIVES: This study sought to evaluate the potential clinical impact of using 3-dimensional echocardiography (3DE) to measure left ventricular ejection fraction (LVEF) in patients considered for implantable cardioverter-defibrillator (ICD) implantation and to assess the predictive value of 3DE LVEF for arrhythmic events. BACKGROUND: ICD therapy is currently recommended to prevent sudden cardiac death in patients with symptomatic heart failure and LVEF ≤35%, and in asymptomatic patients with ischemic heart disease and LVEF ≤30%. Two-dimensional echocardiography (2DE) is currently used to calculate LVEF. However, 3DE has been reported to be more reproducible and accurate than 2DE to measure LVEF. METHODS: The study prospectively enrolled 172 patients with LV dysfunction (71% ischemic). Both 2DE and 3DE LVEF were obtained during the same study. The outcome was the occurrence of major arrhythmic events (sudden cardiac death, aborted cardiac arrest, appropriate ICD therapy). RESULTS: After a median follow up of 56 (range 18 to 65) months, major arrhythmic events occurred in 30% of the patients. Compared with 2DE, 3DE changed the assignment above or below the LVEF thresholds for ICD implantation in 20% of patients, most of them having 2DE LVEFs within ± 10% from threshold. By cause-specific hazard model, 3DE LVEF was the only independent predictor of the occurrence of major arrhythmic events. CONCLUSIONS: LVEF by 3DE was an independent predictor of major arrhythmic events and improved arrhythmic risk prediction in patients with LV dysfunction. When compared with 2DE LVEF, 3DE measurement of LVEF may change the decision to implant an ICD in a sizable number of patients.

Multimodality imaging evaluation of Chagas disease: an expert consensus of Brazilian Cardiovascular Imaging Department (DIC) and the European Association of Cardiovascular Imaging (EACVI).

Aims: To develop a document by Brazilian Cardiovascular Imaging Department (DIC) and the European Association of Cardiovascular Imaging (EACVI) to review and summarize the most recent evidences about the non-invasive assessment of patients with Chagas disease, with the intent to set up a framework for standardized cardiovascular imaging to assess cardiovascular morphologic and functional disturbances, as well as to guide the subsequent process of clinical decision-making. Methods and results: Chagas disease remains one of the most prevalent infectious diseases in Latin America, and has become a health problem in non-endemic countries. Dilated cardiomyopathy is the most severe manifestation of Chagas disease, which causes substantial disability and early mortality in the socially most productive population leading to a significant economical burden. Prompt and correct diagnosis of Chagas disease requires specialized clinical expertise to recognize the unique features of this disease. The appropriate and efficient use of cardiac imaging is pivotal for diagnosing the cardiac involvement in Chagas disease, to stage the disease, assess patients' prognosis and address management. Echocardiography is the most common imaging modality used to assess, and follow-up patients with Chagas disease. The presence of echocardiographic abnormalities is of utmost importance, since it allows to stage patients according to disease progression. In early stages of cardiac involvement, echocardiography may demonstrate segmental left ventricuar wall motion abnormalities, mainly in the basal segments of inferior, inferolateral walls, and the apex, which cannot be attributed to obstructive coronary artery arteries. The prevalence of segmental wall motion abnormalities varies according to the stage of the disease, reaching about 50% in patients with left ventricular dilatation and dysfunction. Speckle tracking echocardiography allows a more precise and quantitative measurement of the regional myocardial function. Since segmental wall motion abnormalities are frequent in Chagas disease, speckle tracking echocardiography may have an important clinical application in these patients, particularly in the indeterminate forms when abnormalities are more subtle. Speckle tracking echocardiography can also quantify the heterogeneity of systolic contraction, which is associated with the risk of arrhythmic events. Three-dimensional (3D) echocardiography is superior to conventional two-dimensional (2D) echocardiography for assessing more accurately the left ventricular apex and thus to detect apical aneurysms and thrombus in patients in whom ventricular foreshortening is suspected by 2D echocardiography. In addition, 3D echocardiography is more accurate than 2D Simpson s biplane rule for assessing left ventricular volumes and function in patients with significant wall motion abnormalities, including aneurysms with distorted ventricular geometry. Contrast echocardiography has the advantage to enhancement of left ventricular endocardial border, allowing for more accurate detection of ventricular aneurysms and thrombus in Chagas disease. Diastolic dysfunction is an important hallmark of Chagas disease even in its early phases. In general, left ventricular diastolic and systolic dysfunction coexist and isolated diastolic dysfunction is uncommon but may be present in patients with the indeterminate form. Right ventricular dysfunction may be detected early in the disease course, but in general, the clinical manifestations occur late at advanced stages of Chagas cardiomyopathy. Several echocardiographic parameters have been used to assess right ventricular function in Chagas disease, including qualitative evaluation, myocardial performance index, tissue Doppler imaging, tricuspid annular plane systolic excursion, and speckle tracking strain. Cardiac magnetic resonance (CMR) is useful to assess global and regional left ventricular function in patients with Chagas diseases. Myocardial fibrosis is a striking feature of Chagas cardiomyopathy and late gadolinium enhancement (LGE) is used to detect and quantify the extension of myocardial fibrosis. Myocardial fibrosis might have a role in risk stratification of patients with Chagas disease. Limited data are available regarding right ventricular function assessed by CMR in Chagas disease. Radionuclide ventriculography is used for global biventricular function assessment in patients with suspected or definite cardiac involvement in Chagas disease with suboptimal acoustic window and contraindication to CMR. Myocardial perfusion scintigraphy may improve risk stratification to define cardiac involvement in Chagas disease, especially in the patients with devices who cannot be submitted to CMR and in the clinical setting of Chagas patients whose main complaint is atypical chest pain. Detection of reversible ischemic defects predicts further deterioration of left ventricular systolic function and helps to avoid unnecessary cardiac catheterization and coronary angiography. Conclusion: Cardiac imaging is crucial to detect the cardiac involvement in patients with Chagas disease, stage the disease and stratify patient risk and address management. Unfortunately, most patients live in regions with limited access to imaging methods and point-of-care, simplified protocols, could improve the access of these remote populations to important information that could impact in the clinical management of the disease. Therefore, there are many fields for further research in cardiac imaging in Chagas disease. How to better provide an earlier diagnosis of cardiac involvement and improve patients risk stratification remains to be addressed using different images modalities.

Physiologic Determinants of Left Atrial Longitudinal Strain: A Two-Dimensional Speckle-Tracking and Three-Dimensional Echocardiographic Study in Healthy Volunteers.

BACKGROUND: Left atrial (LA) longitudinal strain (LS) using two-dimensional speckle-tracking echocardiography has emerged as an important diagnostic and prognostic parameter in various cardiovascular conditions. However, its reference values, their correlations with demographics characteristics, and its physiologic determinants remain to be established. METHODS: Accordingly, 171 healthy volunteers (mean age, 45 ± 12 years; 61% women) in whom LS was obtained from both apical four- and two-chamber dedicated views of the left atrium, considering the P-P interval on the electrocardiogram as the reference cardiac cycle, were prospectively studied. From the LA LS curve we measured the extent of the negative deflection (LSneg), representing LA active contraction, the positive deflection (LSpos) during LA filling, and total LS (LStot), as the sum of LSneg and LSpos values. RESULTS: Average values for biplane LA LSpos, LSneg, and LStot were 19.7%, -14.5%, and 33.3%, respectively. On multivariate analysis, age, left ventricular (LV) global LS and volume, and LV diastolic function were the main physiologic determinants of LA LSpos (R2 = 0.57) and LStot (R2 = 0.40), whereas systolic blood pressure, E/A ratio, global LS, and LV stroke volume were the main determinants of LA LSneg (R2 = 0.20). Women had higher LSpos and LStot than men, particularly before 50 years of age. LA LSpos and LStot decreased with aging, with different trends in men and women. CONCLUSIONS: LA LS values are different in men and women and should be interpreted taking into account patient age and LV function as well. These reference values may help identify subclinical LA dysfunction in several cardiovascular or systemic conditions.

European Association of Cardiovascular Imaging/Cardiovascular Imaging Department of the Brazilian Society of Cardiology recommendations for the use of cardiac imaging to assess and follow patients after heart transplantation.

The cohort of long-term survivors of heart transplant is expanding, and the assessment of these patients requires specific knowledge of the surgical techniques employed to implant the donor heart, the physiology of the transplanted heart, complications of invasive tests routinely performed to detect graft rejection (GR), and the specific pathologies that may affect the transplanted heart. A joint EACVI/Brazilian cardiovascular imaging writing group committee has prepared these recommendations to provide a practical guide to echocardiographers involved in the follow-up of heart transplant patients and a framework for standardized and efficient use of cardiovascular imaging after heart transplant. Since the transplanted heart is smaller than the recipient's dilated heart, the former is usually located more medially in the mediastinum and tends to be rotated clockwise. Therefore, standard views with conventional two-dimensional (2D) echocardiography are often difficult to obtain generating a large variability from patient to patient. Therefore, in echocardiography laboratories equipped with three-dimensional echocardiography (3DE) scanners and specific expertise with the technique, 3DE may be a suitable alternative to conventional 2D echocardiography to assess the size and the function of cardiac chambers. 3DE measurement of left (LV) and right ventricular (RV) size and function are more accurate and reproducible than conventional 2D calculations. However, clinicians should be aware that cardiac chamber volumes obtained with 3DE cannot be compared with those obtained with 2D echocardiography. To assess cardiac chamber morphology and function during follow-up studies, it is recommended to obtain a comprehensive echocardiographic study at 6 months from the cardiac transplantation as a baseline and make a careful quantitation of cardiac chamber size, RV systolic function, both systolic and diastolic parameters of LV function, and pulmonary artery pressure. Subsequent echocardiographic studies should be interpreted in comparison with the data obtained from the 6-month study. An echocardiographic study, which shows no change from the baseline study, has a high negative predictive value for GR. There is no single systolic or diastolic parameter that can be reliably used to diagnose GR. However, in case several parameters are abnormal, the likelihood of GR increases. When an abnormality is detected, careful revision of images of the present and baseline study (side-by-side) is highly recommended. Global longitudinal strain (GLS) is a suitable parameter to diagnose subclinical allograft dysfunction, regardless of aetiology, by comparing the changes occurring during serial evaluations. Evaluation of GLS could be used in association with endomyocardial biopsy (EMB) to characterize and monitor an acute GR or global dysfunction episode. RV size and function at baseline should be assessed using several parameters, which do not exclusively evaluate longitudinal function. At follow-up echocardiogram, all these parameters should be compared with the baseline values. 3DE may provide a more accurate and comprehensive assessment of RV size and function. Moreover, due to the unpredictable shape of the atria in transplanted patients, atrial volume should be measured using the discs' summation algorithm (biplane algorithm for the left atrium) or 3DE. Tricuspid regurgitation should be looked for and properly assessed in all echocardiographic studies. In case of significant changes in severity of tricuspid regurgitation during follow-up, a 2D/3D and colour Doppler assessment of its severity and mechanisms should be performed. Aortic and mitral valves should be evaluated according to current recommendations. Pericardial effusion should be serially evaluated regarding extent, location, and haemodynamic impact. In case of newly detected pericardial effusion, GR should be considered taking into account the overall echocardiographic assessment and patient evaluation. Dobutamine stress echocardiography might be a suitable alternative to routine coronary angiography to assess cardiac allograft vasculopathy (CAV) at centres with adequate experience with the methodology. Coronary flow reserve and/or contrast infusion to assess myocardial perfusion might be combined with stress echocardiography to improve the accuracy of the test. In addition to its role in monitoring cardiac chamber function and in diagnosis the occurrence of GR and/or CAV, in experienced centres, echocardiography might be an alternative to fluoroscopy to guide EMB, particularly in children and young women, since echocardiography avoids repeated X-ray exposure, permits visualization of soft tissues and safer performance of biopsies of different RV regions. Finally, in addition to the indications about when and how to use echocardiography, the document also addresses the role of the other cardiovascular imaging modalities during follow-up of heart transplant patients. In patients with inadequate acoustic window and contraindication to contrast agents, pharmacological SPECT is an alternative imaging modality to detect CAV in heart transplant patients. However, in centres with adequate expertise, intravascular ultrasound (IVUS) in conjunction with coronary angiography with a baseline study at 4-6 weeks and at 1 year after heart transplant should be performed to exclude donor coronary artery disease, to detect rapidly progressive CAV, and to provide prognostic information. Despite the fact that coronary angiography is the current gold-standard method for the detection of CAV, the use of IVUS should also be considered when there is a discrepancy between non-invasive imaging tests and coronary angiography concerning the presence of CAV. In experienced centres, computerized tomography coronary angiography is a good alternative to coronary angiography to detect CAV. In patients with a persistently high heart rate, scanners that provide high temporal resolution, such as dual-source systems, provide better image quality. Finally, in patients with insufficient acoustic window, cardiac magnetic resonance is an alternative to echocardiography to assess cardiac chamber volumes and function and to exclude acute GR and CAV in a surveillance protocol.

Dynamic changes in tricuspid annular diameter measurement in relation to the echocardiographic view and timing during the cardiac cycle.

BACKGROUND: Tricuspid annular (TA) size and function play important roles in planning the need for associated TA annuloplasty in patients undergoing cardiac surgery for left-sided heart valve diseases. However, TA diameter normative values and the extent of TA dynamic changes during cardiac cycle remain to be established. METHODS: This was a prospective, cross-sectional study of 219 healthy volunteers (mean age, 43 ± 15 years; 57% women), using conventional two-dimensional transthoracic echocardiographic (2DE) imaging to assess the variability of TA diameter measurement in relation to 2DE view and timing during cardiac cycle. TA diameter was obtained from apical right ventricular (RV)-focused four-chamber, parasternal long-axis RV inflow, and parasternal short-axis at aortic plane 2DE views at five time points during the cardiac cycle. Right atrial and RV volumes were measured using three-dimensional echocardiography. RESULTS: TA diameters differed significantly among the three 2DE views and changed significantly during the cardiac cycle in all views. Moreover, mean fractional shortening of TA diameter was 24 ± 6% in the four-chamber view, 20 ± 7% in the parasternal long-axis RV inflow view, and 29 ± 11% in the parasternal short-axis at aortic plane view. One multivariate linear regression analysis, age, gender, and right atrial and RV volumes were independently correlated with TA diameters and accounted for 55% of the variance of midsystolic TA diameter in the four-chamber view. CONCLUSIONS: This study provides references values for TA diameters and dynamics using 2DE imaging. Age, gender, and right chamber sizes, as well as the 2DE view and time during the cardiac cycle, significantly influenced TA diameters in healthy individuals. These data may help better identify TA dilatation using 2DE imaging for surgical planning.