Feasibility of real-time three-dimensional echocardiography for the assessment of distorted biventricular systolic function in patients with cor pulmonale

Abstract

Background: This study was to investigate the feasibility of real-time 3-dimensional echocardiography (RT3DE) for the analysis of biventricular ejection fractions and volume measurements in patients with cor pulmonale and the correlations of RT3DE results with 64-slice multi-detector cardiac computed tomography (64-MDCT) results.

Methods: This study included a total of 22 patients (59.3 ± 16.6 years of age; 10 males and 12 females) who showed flattening or reverse curvature of the interventricular septum and severe pulmonary hypertension [mean right ventricular (RV) systolic pressure = 66.8 ± 19.7 mmHg] on 2-dimensional transthoracic echocardiography due to cor pulmonale. Biventricular end-diastolic and end-systolic volumes were measured by RT3DE and 64-MDCT. The severity of D-shaped deformation was evaluated by using left ventricular (LV) eccentricity index (ratio of diameters parallel/perpendicular to the interventricular septum on parasternal short axis images of the papillary muscle level).

Results: There were moderate correlations between biventricular volumes measured by RT3DE and 64-MDCT except for LV end-systolic volume (59.8 ± 17.1 vs. 73.2 ± 20.2 mL, r = 0.652, p = 0.001 for LV end-diastolic volume; 30.6 ± 9.1 vs. 30.8 ± 12.5 mL, r = 0.361, p = 0.099 for LV end-systolic volume; 110.1 ± 42.9 vs. 171.1 ± 55.3 mL, r = 0.545, p = 0.009 for RV end-diastolic volume; and 80.9 ± 35.0 vs. 128.7 ± 45.1 mL, r = 0.549, p = 0.005 for RV end-systolic volume respectively).

Conclusion: This study suggests that RT3DE may be a modest method for measuring distorted biventricular end-systolic and end-diastolic volumes in patients with cor pulmonale.

Keywords: 64-slice multi-detector cardiac computed tomography; Cor pulmonale; D-shaped deformation; Real-time three-dimensional echocardiography; Severe pulmonary hypertension.

Fig. 1

2DE features of cor pulmonale. A: Apical 4 chamber view shows RV and RA enlargement, and underfilled LV. B: Apical 2 chamber view of 2DE has limitations for the evaluation of LV function due to distorted LV, especially in the apical part of the 2 chamber view (arrow) that is caused by compression with dilated RV. C: RVSP is markedly elevated (pressure gradient = 70.5 mmHg). D: Parasternal short axis view. The severity of flattening or reverse curvature of the interventricular septum is described by eccentricity index (ratio of diameters of perpendicular/parallel to the interventricular septum on parasternal short axis images at the papillary muscle level). 2DE: two-dimensional echocardiography, RV: right ventricle, RA: right atrium, LV: left ventricle, LA: left atrium, RVSP: right ventricular systolic pressure.

Fig. 2

Long-axis and short-axis images of the LV in a patient with cor pulmonale from 64-MDCT (A, upper panel) and RT3DE images (A, lower panel), with reconstructed LV endocardial surfaces and volume-time curves. Long-axis and short-axis images of the RV in a patient with cor pulmonale from 64-MDCT (B, upper panel) and RT3DE images (B, lower panel), with reconstructed LV endocardial surfaces and volume-time curves. LV: left ventricle, 64-MDCT: 64-slice multi-detector cardiac computed tomography, RT3DE: real-time three dimensional echocardiography, RV: right ventricle, EF: ejection fraction.

Fig. 3

Moderate degree agreements on Bland-Altman plots are noted in LV end-diastolic and systolic volumes measured by RT3DE and 64-MDCT (A and B). Relatively low degree agreements are noted between Bland-Altman plots of the end-diastolic and systolic volumes of RV as measured by both methods (E and F). Moderate degree of agreements are noted between Bland-Altman plots of the EFs and stroke volumes of the LV and RV as measured by both methods (C, D, G and H). LV: left ventricle, RV: right ventricle, EDV: end-diastolic volume, ESV: end-systolic volume, RT3DE: real-time 3-dimensional echocardiography, 64-MDCT: 64-slice multi-detector cardiac computed tomography, EF: ejection fraction, CTLVSV: cardiac computed tomography left ventricle stroke volume, ELVSV: real-time 3-dimensional echocardiography left ventricle stroke volume, CTRVSV: cardiac computed tomography right ventricle stroke volume, ERVSV: real-time 3-dimensional echocardiography right ventricle stroke volume, CTLVEF: cardiac computed tomography left ventricle ejection fraction, ELVEF: real-time 3-dimensional echocardiography left ventricle ejection fraction, CTRVEF: cardiac computed tomography right ventricle ejection fraction, ERVEF: real-time 3-dimensional echocardiography right ventricle ejection fraction, SD: standard deviation.