Echocardiographic Linear Dimensions for Assessment of Right Ventricular Chamber Volume as Demonstrated by Cardiac Magnetic Resonance

Abstract

Background Echo-derived linear dimensions offer straightforward indices of right ventricular (RV) structure but have not been systematically compared to RV volumes on cardiac magnetic resonance (CMR). Methods Echo and CMR were interpreted among CAD patients imaged via prospective (90%) or retrospective (10%) registries. For echo, American Society of Echocardiography (ASE) recommended RV dimensions were measured in apical 4-chamber (basal RV width, mid RV width, RV length), parasternal long (proximal RV outflow tract [pRVOT]) and short axis (distal RVOT) views. For CMR, RV end-diastolic (RV-EDV) and end-systolic (RV-ESV) volumes were quantified via border planimetry. Results 272 patients underwent echo and CMR within a narrow interval (0.4±1.0 days); complete acquisition of all ASE dimensions was feasible in 98%. All echo dimensions differed between patients with and without RV dilation on CMR (p<0.05). Basal RV width (r=0.70), pRVOT width (r=0.68), and RV length (r=0.61) yielded highest correlations with RV-EDV on CMR; end-systolic dimensions yielded similar correlations (r=0.68, 0.66, 0.65 respectively). In multivariable regression, basal RV width (regression coefficient 1.96 per mm [CI 1.22–2.70], p<0.001), RV length (0.97[0.56–1.37], p<0.001) and pRVOT width (2.62 [1.79–3.44], p<0.001) were independently associated with CMR RV-EDV[r= 0.80]. RV-ESV was similarly associated with echo dimensions (basal RV width; 1.59 per mm [CI 1.06–2.13], p<0.001) | RV length; 1.00 [0.66–1.34], p<0.001) | pRVOT width; 1.80 [1.22–2.39], p<0.001) [r= 0.79]. Conclusions RV linear dimensions provide readily obtainable markers of RV chamber size. Proximal RVOT and basal width are independently associated with CMR volumes, supporting use of multiple linear dimensions when assessing RV size on echo.

Right Ventricular Dysfunction Impairs Effort Tolerance Independent of Left Ventricular Function Among Patients Undergoing Exercise Stress Myocardial Perfusion Imaging

“…It is thus possible that our results would have differed somewhat were RV function assessed volumetrically using 3-dimensional (3D) echo or CMR, which are known to improve RV assessment compared to 2D imaging. 3, 37 On the other hand, TAPSE and S’ have been shown to correlate with volumetric RV function, 20 and offer a means of RV assessment for patients in whom 3D methods (e.g. CMR) are contraindicated or unavailable, providing a rationale for our imaging approach.…”

“…20, 21 RV systolic function was visually scored and quantified via TAPSE and S’, which were acquired in accordance with consensus guidelines: TAPSE was measured (on M-mode) as the distance of systolic excursion of the lateral tricuspid annulus along its longitudinal plane. S’ was measured (on tissue Doppler) as the peak tricuspid annular longitudinal velocity of excursion.…”

Echocardiographic linear fractional shortening for quantification of right ventricular systolic function—A cardiac magnetic resonance validation study

“…Images were acquired in parasternal, as well as apical 2-, 3-, and 4- chamber orientations as detailed in ASE guidelines. [7, 8, 10] Ancillary imaging was performed to assess RV function, including M-mode for TAPSE, as well as tissue Doppler for S’ and RV index of myocardial performance (RIMP), each of which was assessed in apical 4-chamber orientation. [8]…”

“…Analyses were performed by dedicated readers with experience in each respective modality (echo - AS |CMR - JWW), for whom high reproducibility has been previously been reported. [10]…”

“…[7, 10] Pulmonary artery systolic pressure was calculated using the modified Bernoulli equation (4 [peak tricuspid regurgitant [TR] velocity] 2 + right atrial [RA] pressure), for which TR velocity was measured via Doppler and RA pressure based on inferior vena caval size and collapsibility. [11]…”