Tricuspid annulus: A spatial and temporal analysis.

BACKGROUND: Traditional two-dimensional (2D) echocardiographic evaluation of tricuspid annulus (TA) dilation is based on single-frame measurements of the septolateral (S-L) dimension. This may not represent either the axis or the extent of dynamism through the entire cardiac cycle. In this study, we used real-time 3D transesophageal echocardiography (TEE) to analyze geometric changes in multiple axes of the TA throughout the cardiac cycle in patients without right ventricular abnormalities. MATERIALS AND METHODS: R-wave-gated 3D TEE images of the TA were acquired in 39 patients undergoing cardiovascular surgery. The patients with abnormal right ventricular/tricuspid structure or function were excluded from the study. For each patient, eight points along the TA were traced in the 3D dataset and used to reconstruct the TA at four stages of the cardiac cycle (end- and mid-systole, end- and mid-diastole). Statistical analyses were applied to determine whether TA area, perimeter, axes, and planarity changed significantly over each stage of the cardiac cycle. RESULTS: TA area (P = 0.012) and perimeter (P = 0.024) both changed significantly over the cardiac cycle. Of all the axes, only the posterolateral-anteroseptal demonstrated significant dynamism (P < 0.001). There was also a significant displacement in the vertical axis between the points and the regression plane in end-systole (P < 0.001), mid-diastole (P = 0.014), and mid-systole (P < 0.001). CONCLUSIONS: The TA demonstrates selective dynamism over the cardiac cycle, and its axis of maximal dynamism is different from the axis (S-L) that is routinely measured with 2D TEE.

Simulator-based transesophageal echocardiographic training with motion analysis: a curriculum-based approach.

BACKGROUND: Transesophageal echocardiography (TEE) is a complex endeavor involving both motor and cognitive skills. Current training requires extended time in the clinical setting. Application of an integrated approach for TEE training including simulation could facilitate acquisition of skills and knowledge. METHODS: Echo-naive nonattending anesthesia physicians were offered Web-based echo didactics and biweekly hands-on sessions with a TEE simulator for 4 weeks. Manual skills were assessed weekly with kinematic analysis of TEE probe motion and compared with that of experts. Simulator-acquired skills were assessed clinically with the performance of intraoperative TEE examinations after training. Data were presented as median (interquartile range). RESULTS: The manual skills of 18 trainees were evaluated with kinematic analysis. Peak movements and path length were found to be independent predictors of proficiency (P < 0.01) by multiple regression analysis. Week 1 trainees had longer path length (637 mm [312 to 1,210]) than that of experts (349 mm [179 to 516]); P < 0.01. Week 1 trainees also had more peak movements (17 [9 to 29]) than that of experts (8 [2 to 12]); P < 0.01. Skills acquired from simulator training were assessed clinically with eight additional trainees during intraoperative TEE examinations. Compared with the experts, novice trainees required more time (199 s [193 to 208] vs. 87 s [83 to 16]; P = 0.002) and performed more transitions throughout the examination (43 [36 to 53] vs. 21 [20 to 23]; P = 0.004). CONCLUSIONS: A simulation-based TEE curriculum can teach knowledge and technical skills to echo-naive learners. Kinematic measures can objectively evaluate the progression of manual TEE skills.

Tricuspid annular geometry: a three-dimensional transesophageal echocardiographic study.

OBJECTIVE: To demonstrate the clinical feasibility of accurately measuring tricuspid annular area by 3-dimensional (3D) transesophageal echocardiography (TEE) and to assess the geometric differences based on the presence of tricuspid regurgitation (TR). Also, the shape of the tricuspid annulus was compared with previous descriptions in the literature. DESIGN: Prospective. SETTING: Tertiary care university hospital. INTERVENTIONS: Three-dimensional TEE. PARTICIPANTS: Patients undergoing cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Volumetric data sets from 20 patients were acquired by 3D TEE and prospectively analyzed. Comparisons in annular geometry were made between groups based on the presence of TR. The QLab (Philips Medical Systems, Andover, MA) software package was used to calculate tricuspid annular area by both linear elliptical dimensions and planimetry. Further analyses were performed in the 4D Cardio-View (TomTec Corporation GmBH, Munich, Germany) and MATLAB (Natick, MA) software environments to accurately assess annular shape. It was found that patients with greater TR had an eccentrically dilated annulus with a larger annular area. Also, the area as measured by the linear ellipse method was overestimated as compared to the planimetry method. Furthermore, the irregular saddle-shaped geometry of the tricuspid annulus was confirmed through the mathematic model developed by the authors. CONCLUSIONS: Three-dimensional TEE can be used to measure the tricuspid annular area in a clinically feasible fashion, with an eccentric dilation seen in patients with TR. The tricuspid annulus shape is complex, with annular high and low points, and annular area calculation based on linear measurements significantly overestimates 3D planimetered area.

Mitral annular nonplanarity: correlation between annular height/commissural width ratio and the nonplanarity angle.

OBJECTIVE: To compare two methods of mitral annular nonplanarity: the mathematically calculated annular height-to-commissural width ratio (AHCWR) and the echocardiographically derived nonplanarity angle. DESIGN: Prospective. SETTING: Tertiary care university hospital. INTERVENTIONS: Three-dimensional transesophageal echocardiography. PARTICIPANTS: Patients undergoing mitral valve surgery. MEASUREMENTS AND MAIN RESULTS: Using 3-dimensional transesophageal echocardiography, volumetric datasets were acquired from 22 patients undergoing mitral valve surgery. The intraoperative nonplanarity angle was calculated with Mitral Valve Assessment software (Tomtec GmbH, Munich, Germany). Furthermore, the datasets acquired during 3-dimensional transesophageal echocardiography were exported to Matlab software (MathWorks, Natick, MA), which was used to calculate the AHCWR. The nonplanarity angle was seen to correlate favorably with the AHCWR (r = 0.70). CONCLUSIONS: A favorable correlation was found between the nonplanarity angle and the AHCWR. This suggests that the nonplanarity angle can be used to assess mitral annular nonplanarity in a clinically feasible fashion.

Relative contributions of the cerebellar vermis and prefrontal lobe volumes on cognitive function across the adult lifespan.

Recent research has revealed significant relationships between the vermian regions of the cerebellum and cognitive functions typically associated with prefrontal lobe function. These relationships are believed to be supported by anatomical connections between the distant brain regions. Recent evidence also suggests that age-related reductions in the posterior vermis are associated with age-related decline in frontal lobe cognitive functions, but these studies did not consider concomitant age-related atrophy of the prefrontal lobes. In the present study we addressed this issue by examining cognitive and structural MRI data obtained from 251 adults ranging in age from 18 to 79. Cognition was examined with a computerized cognitive battery and volumes of the cerebellar vermian regions and the prefrontal lobes were determined using quantitative morphometry. Results of the study revealed that both prefrontal and vermian volumes were smaller in older adults compared to younger adults, and both volumes correlated with cognitive performances in the older individuals. However, after controlling for prefrontal volume, the relationships between cognitive function and vermian volumes were eliminated, whereas prefrontal lobe volume remained significantly related to cognitive function after controlling for vermian volumes. These results suggest that while a reduction in cerebellar vermian volume does not significantly relate to normal age-related cognitive decline, prefrontal volume is significantly related to cognitive aging. Our results are consistent with the frontal aging hypothesis.