Determination Of Right Ventricular Volumes Research Articles

Echocardiographic determination of right ventricular volumes and ejection fraction: Validation of a truncated cone and rhomboid pyramid formula.

Echocardiographic assessment of right ventricular (RV) measurements may be challenging. The aim of this study was to develop a formula for calculation of RV volumes and function based on measurements of linear dimensions by 2-dimensional (2D) transthoracic echocardiography (TTE) in comparison to cardiovascular magnetic resonance (CMR). 129 consecutive patients with standard TTE and RV analysis by CMR were included. A formula based on the geometric assumptions of a truncated cone minus a truncated rhomboid pyramid was developed for calculations of RV end-diastolic volume (EDV) and RV end-systolic volume (ESV) by using the basal diameter of the RV (Dd and Ds) and the baso-apical length (Ld and Ls) in apical 4-chamber TTE views: RV EDV = 1.21 * Dd2 * Ld, and RV ESV = 1.21 * Ds2 * Ls. Calculations of RV EDV (ΔRV EDV = 10.2±26.4 ml to CMR, r = 0.889), RV ESV (ΔRV ESV = 4.5±18.4 ml to CMR, r = 0.921) and RV EF (ΔRV EF = 0.5±4.0% to CMR, r = 0.905) with the cone-pyramid formula (CPF) highly agreed with CMR. Impaired RV function on CMR (n = 52) was identified with a trend to higher accuracy by CPF than by conventional echocardiographic parameters (tricuspid annular plane systolic excursion (TAPSE) and fractional area change (FAC)). Calculations of RV volumes and RV function by 2D TTE with the newly developed CPF were in high concordance to measurements by CMR. Accuracy for detection of patients with reduced RV function were higher by the proposed 2D TTE CPF method than by conventional echocardiographic parameters of TAPSE and RV FAC.

Determination of Right Ventricular Volume by Combining Echocardiographic Distance Measurements.

The position of the right ventricle (RV), often partly behind the sternum, implies difficulties to image the RV free wall using transthoracic echocardiography (TTE) and consequently limits the possibilities of stroke volume calculations. The aim of this study was to evaluate whether the volume of the right ventricle (RV) can be determined by combining TTE distance measurements that do not need the RV free wall to be fully visualized. The RV volume was approximated by an ellipsoid composed of three distances. Distance measurements, modeled RV stroke volumes (RVSV), and RV ejection fraction (RVEF) were compared to reference values obtained from cardiac magnetic resonance (CMR) imaging for 12 healthy volunteers. Inter-modality comparisons showed that distance measurements were significantly underestimated in TTE compared to CMR. The modeled RV volumes using TTE distance measurements were underestimated compared to reference CMR volumes. There was, however, for TTE an agreement between modeled RVSV and left ventricular stroke volumes determined by biplane Simpson's rule. Similar agreement was shown between modeled RVSV based on CMR distance measurements and the CMR reference. Regarding RVEF, further studies including patients with a wider range of RVEF are needed to evaluate the method. In conclusion, the ellipsoid model of the RV provides good estimates of RVSVs, but volumes based on distance measurements from different modalities cannot be used interchangeably.

Determination of volume–time curves for the right ventricle and its outflow tract for functional analyses

The determination of right ventricular volumes and function is of increasing interest for the postoperative care of patients with congenital heart defects. The presentation of volumetry data in terms of volume-time curves allows a comprehensive functional assessment. By using manual contour tracing, the generation of volume-time curves is exceedingly time-consuming. This study describes a fast and precise method for determining volume-time curves for the right ventricle and for the right ventricular outflow tract. The method applies contour detection and includes a feature for identifying the right ventricular outflow tract volume. The segregation of the outflow tract is performed by four-dimensional curved smooth boundary surfaces defined by prespecified anatomical landmarks. The comparison with manual contour tracing demonstrates that the method is accurate and improves the precision of the measurement. Compared to manual contour tracing the bias is <0.1% ± 4.1% (right ventricle) and -2.6% ± 20.0% (right ventricular outflow tract). The standard deviations of inter- and intraobserver variabilities for determining the volume of the right ventricular outflow tract are reduced to less than half the values of manual contour tracing. The time consumption per patient is reduced from 341 ± 80 min (right ventricle) and 56 ± 11 min (right ventricular outflow tract) using manual contour tracing to 46 ± 9 min for a combined analysis of right ventricle and right ventricular outflow tract. The analysis of volume-time curves for the right ventricle and its outflow tract discloses new evaluation methods in clinical routine and science.

Tricuspid annular plane systolic excursion assessed using MRI for semi-quantification of right ventricular ejection fraction

Accurate determination of right ventricular volume and ejection fraction (RVEF) is established using MRI. Automatic contour detection of the right ventricular endocardial border is not established in clinical practice, resulting in considerable manual efforts to quantify RVEF. Using transthoracic echocardiography (TTE), the tricuspid annular plane systolic excursion (TAPSE) has proved its worth for quantification of RVEF and risk prediction. Therefore, the aim of this study was to clarify whether TAPSE assessed with MRI as a fast and easily obtainable parameter correlated with volumetric quantification of RVEF. Right ventricular volumes and RVEF were measured with the standardised slice-summation method at MRI. MRI-TAPSE was defined as maximum apical excursion of lateral tricuspid annular plane and measured in a four-chamber view using steady-state free precession sequences. Additionally, MRI-TAPSE was compared with TAPSE assessed using TTE. 76 consecutive patients (aged 58±17 years) were examined. At MRI, right end-diastolic volumes were 97±36 ml, right end-systolic volumes were 57±27 ml and the mean RVEF was 42±14%. MRI-TAPSE was determined with 19±6 mm and correlated well at linear regression analysis with volumetric RVEF (r=0.72, p<0.001). Furthermore, MRI-TAPSE discriminated sufficiently between patients with impaired and normal RVEF. Multiplying MRI-TAPSE by 2.5 led to values close to the RVEF by volumetry. Additionally, MRI-TAPSE correlated well with TAPSE determined using TTE. The inter- and intra-observer variabilities of MRI-TAPSE determination were low (3.1% and 1.8%). TAPSE assessed with MRI is a fast and easily obtainable parameter which correlates well with volumetric quantification of RVEF.

Dynamic Assessment of Right Ventricular Volumes and Function by Real-Time Three-Dimensional Echocardiography: A Comparison Study With Magnetic Resonance Imaging in 100 Adult Patients

The aim of this study was to validate a novel real-time three-dimensional echocardiographic (RT3DE) analysis tool for the determination of right ventricular volumes and function in unselected adult patients. A total of 100 consecutive adult patients with normal or pathologic right ventricles were enrolled in the study. A dynamic polyhedron model of the right ventricle was generated using dedicated RT3DE software. Volumes and ejection fractions were determined and compared with results obtained on magnetic resonance imaging (MRI) in 88 patients with adequate acquisitions. End-diastolic, end-systolic, and stroke volumes were slightly lower on RT3DE imaging than on MRI (124.0 +/- 34.4 vs 134.2 +/- 39.2 mL, P < .001; 65.2 +/- 23.5 vs 69.7 +/- 25.5 mL, P = .02; and 58.8 +/- 18.4 vs 64.5 +/- 24.1 mL, P < .01, respectively), while no significant difference was observed for ejection fraction (47.8 +/- 8.5% vs 48.2 +/- 10.8%, P = .57). Correlation coefficients on Bland-Altman analysis were r = 0.84 (mean difference, 10.2 mL; 95% confidence interval [CI], -31.3 to 51.7 mL) for end-diastolic volume, r = 0.83 (mean difference, 4.5 mL; 95% CI, -23.8 to 32.9 mL) for end-systolic volume, r = 0.77 (mean difference, 5.7 mL; 95% CI, -24.6 to 36.0 mL) for stroke volume, and r = 0.72 (mean difference, 0.4%; 95% CI, -14.2% to 15.1%) for ejection fraction. Right ventricular volumes and ejection fractions as assessed using RT3DE imaging compare well with MRI measurements. RT3DE imaging may become a time-saving and cost-saving alternative to MRI for the quantitative assessment of right ventricular size and function.

Cross-sectional echocardiographic determination of right ventricular volume and myocardial mass in children. Normal values and values in children with interatrial communication

AbstractCross-sectional echocardiography was performed on 108 healthy children (7 days – 17 years old) and 55 children (6 months - 16.5 years old) with interatrial communication. Right ventricular end-diastolic volume, end-systolic volume, stroke volume, ejection fraction, muscle volume, and the ratio of muscle to cavity were calculated on the basis of outlined cavity and myocardium of an apical fourchamber view.In the normal subjects right ventricular end-diastolic volume, end-systolic volume, stroke volume and muscle volume correlated with body surface area (end-diastolic volume: y=12.5x+7.8x2, r=0.99; end-systolic volume: y=4.8x+3.6x2, r=0.98; stroke volume: y=7.7x+4.2x2, r=0.98; muscle volume: y=14.1x+2.9x2, r=0.97), muscle/cavity ratio (0.85±0.17) and ejection fraction (58.9 ± 6.2%) were unrelated to body surface area. In the subjects with interatrial communication, the right ventricular volumes were significantly larger (p&lt;0.001) than the normal values with a linear relationship to the ratio of pulmonary to systemic flows.Right ventricular volumes can be determined in normal children with acceptable repeatability using a standard apical four-chamber view. The growth related normal values provide a basis for future quantitative studies.

Effect of balloon valvuloplasty for mitral stenosis on right ventricular function

Percutaneous balloon mitral valvuloplasty has become a common procedure in the treatment of pliable mitral stenosis. By this method, mitral valve area can usually be doubled, thus leading to significant hemodynamic and clinical improvements. 1,2 However, because evaluation of right ventricular volumes by contrast angiography or radionuclide methods is quite cumbersome and requires greater technical efforts, only few data exist on the effects of this procedure on right ventricular performance. 3 Recently, the evaluation of right ventricular function was made easier by the introduction of a computerized thermodilution catheter, thereby enabling bedside determination of right ventricular volumes and ejection fraction. 4,5 This method showed good correlation with contrast angiography and radionuclide methods. 4,5 Aim of the following study was the investigation of balloon mitral valvuloplasty on right ventricular function at rest and during exercise.

Determination of left ventricular volumes with use of a new nongeometric echocardiographic method: Clinical validation and potential application

A new nongeometric echocardiographic technique for measurement of right and left ventricular volumes was recently validated in vitro. With this method, all images are taken from one point on the chest wall as the transducer is tilted through the ventricle. This approach offers several advantages. No geometric assumptions about ventricular shape are made. All images are acquired from the best echocardiographic window. Furthermore, the digitized points can be used to make a three-dimensional reconstruction of the ventricle.The present study addresses the clinical feasibility of imaging the heart from a single pivoting point in short axis and compares the accuracy of the method in determining left ventricular volumes with that of biplane cineangiography. Twenty-four patients underwent echocardiographic studies within 2 h before angiography. At catheterization, volumes determined by the biplane area-length method ranged between 95 and 368 ml at end-diastole and between 15 and 303 ml at end-systole. A good correlation was observed between ventricular volumes by angiography and echocardiography at end-diastole and end-systole (r = 0.92 and 0.96, respectively). Correlations between volumes by the two techniques were equally good in patients with wall motion abnormalities (n = 13; r = 0.97). Ventricular ejection fraction ranged between 18% and 84% at angiography and correlated well with echocardiographic measurements (r = 0.82).Thus, the echocardiographic tilt method provides accurate determination of left ventricular volume and ejection fraction. This nongeometric method offers the potential for the determination of right ventricular volume and three-dimensional display of the heart.

Determination of right ventricular volumes during aortic surgery

The aim of the present study was to evaluate right ventricular (RV) preload by measurements of right ventricular volumes during aortic clamping and unclamping. Nine patients (aged 67 ± 9 years) undergoing infrarenal aortic aneurysmectomy were monitored with a pulmonary artery catheter equipped with a fast-response thermistor, allowing determination of RV volumes by the thermodilution technique. Anesthesia consisted of a continuous infusion of alfentanil and 50% N20. Aortic clamping resulted in a significant decrease in cardiac index (CI) and a significant increase in systemic vascular resistance (SVR). There was no significant change in right ventricular ejection fraction (RVEF) (from 35% ± 6% to 33% ± 8%) in the presence of a significant decrease in stroke index (from 37.2 ± 9.8 to 31.1 ± 10.0 mL/beat/m 2, P < 0.05), indicating a significant decrease in RV end-diastolic volume (from 106 ± 17 to 92 ± 19 mL, P < 0.01). There were no significant changes in cardiac filling pressures. Aortic unclamping was associated with a significant increase in CI and a significant decrease in SVR. There were no significant changes in cardiac filling pressures, RVEF, or RV volumes. Measurements of RV volumes indicated that aortic clamping resulted in a decrease in RV preload, which is usually not demonstrated by measurements of right atrial pressure alone.

Determination of Right Ventricular Volume by Two-Dimensional Echocardiography With a Crescentic Model

Right ventricular volume in 14 fixed hearts from dogs was determined by echocardiography with an algorithm that takes into consideration the crescentic shape of the right ventricular (RV) cross-sectional area. To validate this model the volumes obtained by echocardiography were compared with volumes obtained by water displacement of silicone casts of the same 14 hearts. A strong linear correlation was demonstrated between the echocardiographic volumes and the volumes obtained by water displacement of RV casts (r = 0.96). The results also showed that the echocardiographic volume determination underestimated the RV volume obtained from cast with an almost constant ratio averaging 0.755 as a result of the exclusion of the RV outflow tract volume from the echocardiographic model. We conclude that a crescentic model allows accurate echocardiographic determination of RV volume.

Thermodilution determination of right ventricular volume and ejection fraction: A comparison with biplane angiography : Urban P, Scheiddegger D, Gabathuler J, et al: Crit Care Med 15:652–655,1987

Thermodilution determination of right ventricular volume and ejection fraction: A comparison with biplane angiography : Urban P, Scheiddegger D, Gabathuler J, et al: Crit Care Med 15:652–655,1987

Measurement of right ventricular volume using cine computed tomography.

Volume measurements of the right ventricle are clinically important, particularly in the assessment of congenital heart disease. The complex configuration of the right ventricular cavity, however, makes assessment of its volume difficult. Cine computed tomography (CT) permits depiction of cardiac anatomy in parallel, sequential, high-resolution tomographic images. To test whether cine CT would allow accurate, reproducible determination of right ventricular volumes, 11 excised, fixed canine hearts were scanned ex vivo. The endocardial contours of the right ventricular cavity were traced by two independent observers. The right ventricular cavity areas were measured in each image and right ventricular volume calculated by a Simpson's rule approximation. Actual right ventricular volume (range 24-86.5 mL) was measured by cavity fluid capacity. Right ventricular volumes derived from cine CT data correlated closely with actual volumes (R = .96, cine CT volume = 0.99 X [actual volume] + 0.2 mL). Interobserver correlation was excellent (R = .99). It is concluded that cine CT scanning permits accurate, reproducible determination of right ventricular volume ex vivo. This technique should be immediately applicable to the noninvasive evaluation of right ventricular function in children and adults.

Right ventricular volume in congenital heart disease

Methods for angiographic determination of right ventricular volume were compared in right ventricular cast studies and in vivo using a semiautomated Simpson's rule, elliptical and rectangular cross sections and a simple geometric model, a prism with a triangular base. In cast studies excellent correlation coefficients were obtained for all three methods ( r = 0.97 to 0.98). In vivo, excellent linear correlation was obtained when the methods were compared ( r = 0.98 to 0.99, P < 0.001). Normal mean right ventricular volumes (70 patients) in milliliters per square meter±1 standard deviation were: end-diastolic volume 64 ± 15, end-systolic volume 25 ± 8 and stroke index 39 ± 11; ejection fraction was 0.61 ± 0.08. Normal mean left ventricular end-diastolic and end-systolic volumes (77 patients) were lower (59 and 19, respectively), and ejection fraction was higher (0.68). Stroke index was the same. Other results showed decreased mean end-diastollc and end-systolic volumes and stroke index, increased ejection fraction ( P < 0.001, < 0.025, < 0.025 and < 0.005, respectively) in 34 patients with pulmonary stenosis, and increased mean end-diastolic and end-systolic volumes and stroke index ( P <0.001, <0.050, <0.001, respectively) in 11 patients with an atrial left to right shunt. In both groups postoperatively, as well as in patients with a ventricular septal defect, tetralogy of Fallot or myocardial disease, mean volumes and ejection fraction were normal. We conclude that a geometric model can be used to determine right ventricular volume with accuracy. In children, the right ventricle can adapt reversibly to chronic increases in afterload and preload; it is not necessarily overloaded by a ventricular septal defect or tetralogy of Fallot, and it is relatively unaffected by severe myocardial disease.