Mitra Shirazi

Nonvolumetric Echocardiographic Indices of Right Ventricular Systolic Function: Validation with Cardiovascular Magnetic Resonance and Relationship with Functional Capacity

Purpose: Right ventricular (RV) systolic function as measured by right ventricular ejection fraction (RVEF) has long been recognized as an important predictor of outcome in heart failure patients. The echocardiographic measurement of RV volumes and RVEF is challenging, however, owing to the unique geometry of the right ventricle. Several nonvolumetric echocardiographic indices of RV function have demonstrated prognostic value in heart failure. Comparison studies of these techniques with each other using RVEF as a benchmark are limited, however. Furthermore, the contribution of these various elements of RV function to patient functional status is uncertain. We therefore aimed to: (1) Determine which nonvolumetric echocardiographic index correlates best with RVEF as determined by cardiac magnetic resonance (CMR) imaging (the accepted gold standard measure of RV systolic function) and (2) Ascertain which echocardiographic index best predicts functional capacity. Methods: Eighty‐three subjects (66 with systolic heart failure and 17 healthy controls) underwent CMR, 2D echocardiography, and cardiopulmonary exercise testing for comparison of echocardiographic indices of RV function with CMR RVEF, 6‐minute walk distance and VO2 PEAK. Results: Speckle tracking strain RV strain exhibited the closest association with CMR RV ejection fraction. Indices of RV function demonstrated weak correlation with 6‐minute walk distance, but basal RV strain rate by tissue velocity imaging had good correlation with VO2 PEAK. Conclusion: Strain by speckle tracking echocardiography and strain rate by tissue velocity imaging may offer complementary information in the evaluation of RV contractility and its functional effects. (Echocardiography 2012;29:455‐463)

Aortic plaque defined by contrast transthoracic echocardiography

The authors explore the use of third generation echo contrast to define plaque in the ascending aorta and exclude more invasive procedures.

Optimal planimetry location for MRI-derived mitral inflow velocity assessment of diastolic function

Background Diastolic function is almost exclusively assessed using transthoracic echocardiography (TTE), however velocityencoded phase-contrast imaging permits diastolic evaluation with cardiac magnetic resonance (CMR). However, previous studies have utilized heterogeneous planimetric contour locations to measure mitral valve (MV) inflow velocities and the optimal contour is uncertain. We therefore evaluated CMR MV inflow velocities measured at various regions against TTE to identify the optimal method.

Validation of echocardiographic indices of right ventriclular systolic function with cardiac magnetic resonance: a comparative study

Right ventricular ejection fraction (RVEF) is an important predictor of outcome in heart failure patients. Although cardiac magnetic resonance (CMR) assessment of RV function is considered gold standard and echocardiographic measurement of RVEF is challenging due to its unique geometry; CMR still has limited availability in the wider community. Therefore alternative echocardiographic indices such as tricuspid annular plane systolic excursion (TAPSE), peak tricuspid annular systolic velocity (RV S’) and RV fractional area change (RV FAC) have been evaluated and demonstrated prognostic value, however, comparison studies with RVEF by CMR are limited.

Structural and functional characterisation of new-onset idiopathic dilated cardiomyopathy, and its response to therapy

Introduction The prevalence of myocardial fibrosis among patients with idiopathic dilated cardiomyopathy (IDCM), as detected by the late-gadolinium cardiac magnetic resonance (LG-CMR) technique, is reported to be 28-42% in highly-selected samples from specialist heart failure clinics. The presence of fibrosis has been demonstrated to predict the incidence of major adverse cardiovascular events. However, as the heart failure duration prior to first CMR imaging in these studies was at least 12 months the prevalence of myocardial fibrosis at presentation is unknown. Moreover, the determinants of the response-to-therapy of newly diagnosed IDCM patients have not been characterised using CMR and advanced echocardiographic techniques.