Digital processing of contrast echocardiograms: a new technique for measuring right ventricular ejection fraction

Imaging of the right ventricle with 2-dimensional echocardiography (2-D echo) is hampered by trabeculation of the right ventricular (RV) endocardial surface and by limited echocardiographic resolution. Determination of RV ejection fraction (EF) is thus often an inconsistent and tedious procedure. The process of digital subtraction contrast echocardiography was developed to maximize echocardiographic definition of the right ventricle and to assess RVEF with minimal operator interaction. Videotaped 2-D echocardiograms recorded during i.v. injection of agitated saline were digitized. Masks were constructed from end-systolic and end-diastolic apical 4-chamber and parasternal RV short-axis images. Masks were subtracted from corresponding images recorded with contrast in the right ventricle; images of the contrast alone were extracted and their areas determined. EF was calculated from raw area measurements and after conversion to volume. Comparison with RVEF measured by first-pass radionuclide angiography yielded the following correlation coefficients: 4-chamber RV area, r = 0.79; parasternal short-axis RV area, r = 0.59; ellipsoid approximation RV volume, r = 0.84; pyramidal RV volume, r = 0.79; and Simpson's rule triangular cylinder RV volume, r = 0.62. Digital subtraction contrast echocardiography is a new method that can be used for semiautomated determination of RVEF. Further studies to assess the clinical values of digital image processing of 2-D echocardiograms to measure RV function appear warranted.     

Two-dimensional echocardiographic assessment of left atrial size in children

The ability of 2-dimensional echocardiography (2-D echo) to estimate end-systolic left atrial (LA) size and volume was assessed in 140 infants and children. These subjects were divided into 2 groups. Group A included 91 patients with normal LA volume and Group B included 49 patients with LA volume overload. Five echocardiographic views (left parasternal long-axis, left parasternal short-axis, apical 4-chamber, apical 2-chamber and subcostal 4-chamber) were used. From these views, the LA long-axis and minor-axis lengths were measured and the area was planimetered. These echocardiographically derived measurements were compared with angiographically calculated LA volume. Although all echocardiographic measurements correlated well with angiographic LA volume measurements, the echocardiographic area tracked better than length measurements. Echo LA volume was calculated using 5 single-plane and 3 biplane area-length methods. LA volume calculated from either single- or biplane methods correlated well with angiographically determined LA volume. The degree of correlation depended on the method used. Echocardiographic area and estimated LA volume measured from the parasternal long-axis and apical 2-chamber views best separated patients with LA volume overload from normal. Two-dimensional echo using these views accurately segregated all patients with a LA volume >180% of normal and 15 of 21 patients (71%) with an LA volume between 138% and 179% of normal. Thus, 2-D echo is useful in the evaluation of LA size and volume in Infants and children.     

Quantification of right ventricular volumes and function by real time three-dimensional echocardiographic longitudinal axial plane method: validation in the clinical setting

BACKGROUND: Measurement of right ventricular (RV) volumes and right ventricular ejection fraction (RVEF) by three-dimensional echocardiographic (3DE) short-axis disc summation method has been validated in multiple studies. However, in some patients, short-axis images are of insufficient quality for accurate tracing of the RV endocardial border. This study examined the accuracy of long-axis analysis in multiple planes (longitudinal axial plane method) for assessment of RV volumes and RVEF. METHODS: 3DE images were analyzed in 40 subjects with a broad range of RV function. RV end-diastolic (RVEDV) and end-systolic volumes (RVESV) and RVEF were calculated by both short-axis disc summation method and longitudinal axial plane method. RESULTS: Excellent correlation was obtained between the two methods for RVEDV, RVESV, and RVEF (r = 0.99, 0.99, 0.94, respectively; P < 0.0001 for all comparisons). CONCLUSION: 3DE longitudinal-axis analysis is a promising technique for the evaluation of RV function, and may provide an alternative method of assessment in patients with suboptimal short-axis images.     

Method for estimating right ventricular volume by planes applicable to cross-sectional echocardiography: correlation with angiographic formulas

Right ventricular (RV) volumes determined by echocardiography were compared with those measured using established angiographic formulas. RV cast displacement volumes were first correlated with data derived from radiographic images of the casts corresponding to standard anglographic RV views. Four established anglographic formulas (Ferlinz, Boak, Fisher and Thilenius) correlated well with cast volume, with the corrected prism method of Fisher showing a best fit (r = 0.98, Y = 1.1 + 0.9x, standard error of the ESTIMATE = 3.6). Cast volumes calculated using our echocardiographic formula were then examined relative to the volumes derived from radiographic images of the RV casts. Volumes Calculated using the corrected area-length Thilenius formula correlated best with those obtained using our derived 2-dimensional echocardiographic formula (r = 0.96, Y = 4.6 + 1.0x, standard error of the ESTIMATE = 6.8). These data confirm that volume calculated using the suggested optimal echocardiographic formula correlates well with volume obtained using derived angiographic data. Accordingly, confirmation In humans by the use of angiography is a rational step.     

Three echocardiographic methods in right ventricular function evaluation

We employed two-dimensional echocardiography for the assessment of right ventricular (RV) volumes and/or function in a series of 44 patients. The results of three different echocardiographic approaches were compared with the data obtained from single-plane RV angiography following ultrasound within a 7-day interval. Only the echocardiographic area length method with two orthogonal imaging planes employed (apical 4-chamber and subcostal projections) yielded the beneficial results. The correlations between echocardiographic and angiographic RV volume estimates were rather high (end-diastolic volume: r = 0.83, end-systolic volume: r = 0.82, stroke volume: r = 0.81) and satisfactory in ejection fraction (r = 0.75). Using the method mentioned, the differentiation of patients with an angiographic evidence of RV failure (echocardiographic ejection fraction less than 0.55) from those without it was possible with a sensitivity of 0.68 and a specificity of 0.82. Concerning the clinical impact of the presented study, we can recommend the technique in question as a screening procedure for the detection of changes in RV function exceeding 12% (95% confidence limits).     

Global and regional right ventricular function in normal infants and infants with transposition of the great arteries after Senning operation

Echocardiographic assessment of right ventricular size, global function, and regional wall motion was performed in 29 normal infants and 19 infants with transposition of the great arteries 1 to 41 months after they underwent the Senning procedure. Sixteen of the patients with transposition of the great arteries were in clinically good condition and three had congestive heart failure. The right ventricular endocardial surface was digitized frame by frame for a complete cardiac cycle in both subxiphoid long-axis (coronal plane) and short-axis (parasagittal plane) views, and the cross-sectional area and the area change fraction (AF) were calculated. In each plane the right ventricular wall was subdivided into four anatomic regions (infundibular, free wall, diaphragmatic, and septal). With the use of a floating point center of mass model the direction and average extent of motion of the endocardium was determined for each region. In normal infants the infundibular and free wall portions of the right ventricle exhibited the greatest inward motion and the septal segments the least inward motion. Although the maximal area in both long-axis (r = .85) and short-axis (r = .85) views was highly correlated with body surface area (BSA), neither global nor regional function was significantly correlated with age or BSA. In clinically well patients after Senning procedure regional right ventricular function followed an entirely different pattern than that seen in normal infants. The endocardium of the septal segments showed the greatest inward motion in systole. In contrast to those in normal infants, maximal and minimal cross-sectional areas did not correlate significantly with BSA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Two-dimensional assessment of right ventricular function: an echocardiographic-MRI correlative study

BACKGROUND: While echocardiography is used most frequently to assess right ventricular (RV) function in clinical practice, echocardiography is limited in its ability to provide an accurate measure of RV ejection fraction (RVEF). Hence, quantitative estimation of RV function has proven difficult in clinical practice. OBJECTIVE: We sought to determine which commonly used echocardiographic measures of RV function were most accurate in comparison with an MRI-derived estimate of RVEF. METHODS: We analyzed RV function in 36 patients who had cardiac MRI studies and echocardiograms within a 24 hour period. 2D parameters of RV function-right ventricular fractional area change (RVFAC), tricuspid annular motion (TAM), and transverse fractional shortening (TFS) were obtained from the four-chamber view. RV volumes and EFs were derived from volumetric reconstruction based on endocardial tracing of the RV chamber from the short axis images. Echocardiographic assessment of RV function was correlated with MRI findings. RESULTS: RVFAC measured by echocardiography correlated best with MRI-derived RVEF (r = 0.80, P < 0.001). Neither TAM (r = 0.17; P = 0.30) nor TFC (r = 0.12; p< 0.38) were significantly correlated with RVEF. CONCLUSIONS: RVFAC is the best of commonly utilized echocardiographic 2D measure of RV function and correlated best with MRI-derived RV ejection fraction. CONDENSED ABSTRACT: While echocardiography is used most frequently to assess RV function in clinical practice, echocardiography is limited in its ability to provide an accurate measure of RV ejection fraction (RVEF). Using cardiac MRI, RV fractional area change (RVFAC), determined either by MRI or echocardiography, was found to correlate best with MRI-derived RVEF.     

Two-dimensional echocardiographic assessment of right ventricular volume in children with congenital heart disease

The ability of 2-dimensional echocardiography to measure right ventricular (RV) volume and ejection fraction was assessed in 22 children with congenital heart disease. From the apical 4 chamber 2-dimensional echocardiographic image, the long-axis length of the right ventricle was measured and the area planimetered. On the anteroposterior and lateral cineangiocardiographic planes, the right ventricle was separated into 2 parts: RV sinus and outflow tract. The longest length, inflow tract length, and area of the sinus were measured from biplane cineangiographic views. The echographic long-axis length correlated well with the longest length of the RV sinus measured from both anteroposterior and lateral cineangiographic views at both end-systole and end-diastole. Moreover, the echographic area correlated well with the sinus area obtained from both cineangiographic views. From these regression analyses, the echographic long axis length and area were corrected to the angiographie longest length and area of the sinus. The new corrected echographic longest length and area were applied to 3 formulas (2 biplane and 1 uniplane) to calculate the sinus volume of the right ventricle. Total RV volume was then derived from the sinus volume. RV volumes and ejection fraction determined by 2-dimensional echocardiography were compared with those obtained from biplane cineangiography using Simpson's rule method. All formulas tested predicted RV volumes and ejection fraction with equal accuracy. Thus, 2-dimensional echocardiography can assess RV volume and ejection fraction in children with congenital heart disease.     

Normal reference values for the adult right ventricle by magnetic resonance imaging

The purpose of this study was to establish reference ranges for magnetic resonance imaging (MRI) measurements of the adult right ventricle stratified by gender. Cardiovascular MRI is increasingly used for evaluating the right ventricle in congenital and acquired heart disease, but gender-specific normative values are currently unavailable. Study participants included 500 subjects free of clinical cardiovascular disease who were participants in the Multi-Ethnic Study of Atherosclerosis (MESA). All subjects underwent MRI according to a standard protocol. The endocardial margins of the right ventricle were manually contoured on short-axis images, and right ventricular (RV) volumes were calculated using a summation-of-disks method. RV dimensions were measured on 4-chamber gradient-echo images and in the short-axis plane. Except for the ejection fraction, all unadjusted RV parameters were significantly greater in men than in women (p <0.001). In the entire study population, RV volumes and linear dimensions each correlated significantly with height (r = 0.38 to 0.64, p = 0.001 for all) and body surface area (r = 0.41 to 0.64, p = 0.001 for all). Gender differences persisted after adjustment for subject height. After adjustment for body surface area, volumetric variables remained significantly greater (p = 0.001) in men than in women. Even after adjusting for body surface area and height, Chinese participants had significantly lower RV volumes compared with Caucasians. In conclusion, gender-specific normal values for the adult right ventricle by MRI are presented. Cardiovascular MRI measures of RV volumes and linear dimensions differ significantly according to gender and body size. These values will be useful to differentiate RV health from diseases that result in abnormal RV structure and function.     

Left ventricular volume determined echocardiographically by assuming a constant left ventricular epicardial long-axis/short-axis dimension ratio throughout the cardiac cycle.

OBJECTIVES. The purpose of this study was to develop and test a simplified echocardiographic method to calculate left ventricular volume. BACKGROUND. This method was based on the assumption that the ratio of the left ventricular epicardial long-axis dimension to the epicardial short-axis dimension was constant throughout the cardiac cycle. With use of this constant ratio, the method developed to calculate left ventricular volume at a given point in the cardiac cycle required the left ventricular endocardial long-axis dimension to be measured at only one point in the cardiac cycle. METHODS. Studies were performed in 13 normal dogs, 8 normal puppies, 9 normal pigs, 12 dogs with aortic stenosis, 13 dogs with acute mitral regurgitation, 12 dogs with chronic mitral regurgitation, 7 dogs that had undergone mitral valve replacement and 6 pigs that had had chronic supraventricular tachycardia. Animals with aortic stenosis developed left ventricular pressure overload hypertrophy with a 60% increase in left ventricular mass; chronic mitral regurgitation caused left ventricular volume overload hypertrophy with a 46% increase in left ventricular volume; supraventricular tachycardia caused a dilated cardiomyopathy with a 55% decrease in left ventricular ejection fraction. RESULTS. The left ventricular epicardial long-axis/short-axis dimension ratio remained constant throughout the cardiac cycle in each animal group. End-diastolic and end-systolic volumes calculated with the simplified echocardiographic method correlated closely with angiographically measured volumes; for end-diastolic volume, echocardiographic end-diastolic volume = 1.0 (angiographic end-diastolic volume) -1.8 ml, r = 0.96; for end-systolic volume, echocardiographic end-systolic volume = 0.98 (angiographic end-systolic volume) -0.7 ml, r = 0.95. CONCLUSIONS. Thus the left ventricular epicardial long-axis/short-axis dimension ratio was constant throughout the cardiac cycle in a variety of animal species and age groups and in the presence of cardiac diseases that significantly altered left ventricular geometry and function. The simplified echocardiographic method examined provided an accurate determination of left ventricular volumes.     

Assessment of right ventricular function using two-dimensional echocardiography

With the use of two-dimensional echocardiography (2DE), we analyzed apical and subcostal four-chamber views for evaluation of right ventricular (RV) function in 30 individuals as compared to RV ejection fraction (RVEF) obtained by radionuclide angiography. In addition to previously reported parameters of changes in areas and chords, a new simple measurement of tricuspid annular excursion was correlated with RVEF. A close correlation was noted between tricuspid annular plane systolic excursion (TAPSE) and RVEF (r = 0.92). The RV end-diastolic area (RVEDA) and percentage of systolic change in area in the apical four-chamber view also showed close correlation with RVEF (r = -0.76 and 0.81); however, the entire RV endocardium could only be traced in about half of our patients. The end-diastolic transverse chord length and the percentage of systolic change in chord length in the apical view showed a poor correlation with RVEF. The correlation between RVEF and both areas and chords measured in the subcostal view was poor. It is concluded that the measurement of TAPSE offers a simple echocardiographic parameter which reflects RVEF. This measurement is not dependent on either geometric assumptions or traceable endocardial edges. When the endocardial outlines could be traced, the apical four-chamber view was superior to the subcostal view in assessment of RV function.     

Assessment of right ventricular function using echocardiographic speckle tracking of the tricuspid annular motion: comparison with cardiac magnetic resonance

Background: Assessment of right ventricular (RV) function is difficult due to the complex shape of this chamber. Tricuspid annular plane systolic excursion (TAPSE) measured with M-mode echocardiography is frequently used as an index of RV function. However, its accuracy may be limited by ultrasound beam misalignment. We hypothesized that two-dimensional (2D) speckle tracking echocardiography (STE) could provide more accurate estimates of RV function. Accordingly, STE was used to quantify tricuspid annular displacement (TAD), from which RV longitudinal shortening fraction (LSF) was calculated. These STE derived indices were compared side-by-side with M-mode TAPSE measurements against cardiac magnetic resonance (CMR) derived RV ejection fraction (EF). Methods: Echocardiography (Philips iE33, four-chamber view) and CMR (Siemens, 1.5 T) were performed on the same day in 63 patients with a wide range of RV EF (23–70% by CMR). TAPSE was measured using M-mode echocardiography. TAD and RV LSF were obtained using STE analysis (QLAB CMQ, Philips). TAPSE, TAD and RV LSF values were compared with RV EF obtained from CMR short axis stacks. Results: STE analysis required <15 seconds and was able to track tricuspid annular motion in all patients as verified visually. Correlation between RV EF and TAD (0.61 free-wall, 0.65 septal) was similar to that with M-mode TAPSE (0.63). However, STE-derived RV LSF showed a higher correlation with CMR EF (r = 0.78). Conclusion: RV LSF measurement by STE is fast and easy to obtain and provides more accurate evaluation of RV EF than the traditional M-mode TAPSE technique, when compared to CMR reference. (Echocardiography 2012;29:19-24)     

Percentage of shortening of the echocardiographic left ventricular dimension. Its use in determining ejection fraction and stroke volume

The percentage of shortening of the echocardiographic left ventricular dimension (% delta D) was prospectively evaluated in 42 patients without detectable asynergy during diagnostic cardiac catheterization and was found to correlate well with angiographic ejection fraction (r = 0.90). Ejection fraction was calculated as the product of % delta D X 1.7 or as % delta (D2), both formulae having similar degrees of accuracy and a better correlation with the angiographic determination than conventional formulae. Ejection fractions (angiographic and echocardiographic) of 51 percent or greater were always associated with a % delta D of 30 percent or more. In five patients the echocardiographically derived ejection fractions were normal (greater than or equal to 51 percent), while the angiographic ejection fractions were reduced; four of these patients had valvular regurgitation. End-diastolic volumes were calculated from end-diastolic echocardiographic dimensions utilizing a linear regression equation derived from correlating the end-diastolic echocardiographic dimension with the end-diastolic volume in 27 patients without valvular regurgitation (end-diastolic echocardiographic dimension ranged from 3.7 to 8.2 cm). The value for stroke volume determined as the product of calculated end-diastolic volume times ejection fraction correlated with the angiographically determined stroke volume (r = 0.88; standard error of estimate, +/- 11 ml) better than the value for stroke volume derived from conventional echocardiographic formulae.     

Echocardiographic knowledge-based reconstruction for quantification of the systemic right ventricle in young adults with repaired D-transposition of great arteries

The systemic right ventricle (RV) in congenital heart disease is susceptible to progressive dilation and dysfunction. A 2-dimensional echocardiographic means for serial monitoring of the RV would be of great value in this clinical setting. We used 2-dimensional echocardiography with knowledge-based reconstruction (2DE-KBR) for evaluation of systemic RV. Patients with d-transposition of great arteries repaired with an atrial switch and without implanted pacemakers were prospectively recruited for same-day 2DE-KBR and cardiac magnetic resonance (CMR) imaging. RV images were acquired in various 2-dimensional imaging planes using a 3-dimensional space-localizing device attached to the imaging transducer and 3-dimensional reconstruction was performed. RV end-diastolic volume, end-systolic volume, and ejection fraction (EF) were calculated and compared to volumetric CMR analysis. Fifteen patients (7 women, 8 men, 24 ± 7 years old, weight 67 ± 12 kg) were studied. There was good agreement of 2DE-KBR and CMR measurements. Mean RV end-diastolic volume was 221 ± 39 ml with 2DE-KBR and 231 ± 35 ml with CMR (r = 0.80); mean end-systolic volume was 129 ± 35 ml with KBR and 132 ± 30 ml with CMR (r = 0.82), and EF was 42 ± 10% with KBR and 43 ± 7% with CMR (r = 0.86). For 2DE-KBR mean interobserver variabilities were 4.6%, 2.6%, and 4.3%; intraobserver variabilities were 3.2%, 3.1%, and 2.3%, respectively, for end-diastolic volume, end-systolic volume, and EF. In conclusion, this study demonstrates the clinical feasibility of quantifying systemic RV volumes and function using 2DE-KBR in adolescents and young adults with repaired d-transposition of great arteries and good agreement of measurements with CMR.     

Left ventricular short-axis plane for magnetic resonance imaging: its clinical importance and applications

Left ventricular short-axis images were obtained by ECG-gated magnetic resonance imaging (MRI) in nine patients with hypertrophic cardiomyopathy and seven patients with chest pain, all of whom had diagnostic cardiac catheterization including angiography. The accuracy and usefulness of the short-axis image in MRI for measuring wall thickness and dimension and for calculating ejection fraction were evaluated. All patients were examined on an examination couch in the right anterior oblique position in optimal positions to obtain the left ventricular long-axis images in the Z-X plane (conventional coronal plane). Next, the paraxial mode was used to obtain the short-axis images by rotating the Y-Z plane (conventional sagittal plane) around the Y axis. The intervals between the trigger on the middle point of the upstroke of the R wave and the 90 degree pulse of saturation recovery spin echo sequence were 40 msec and 340 msec with a 34 msec echo delay time for the end-diastolic and end-systolic images, respectively. Short-axis images in MRI in end-diastole were utilized to measure wall thickness and dimension in patients with hypertrophic cardiomyopathy and the measurements obtained were compared with those of echocardiography. As for calculating ejection fraction in patients with chest pain, the length of the left ventricular long axis (L) was measured using the MRI long-axis image. The intraventricular sectional area at four levels (S1, S2, S3, S4) were measured using the MRI short-axis image in end-diastole and in end-systole. Left ventricular end-diastolic and end-systolic volumes were calculated using the following formula: V = 1/2 X (L -4.5) X S1 + 1.5 X (S1 + S2 + S3) + 1/3 X 1/2 X (L -4.5) X S4. Ejection fraction by MRI was compared with that by cardiac catheterization (single plane, area-length method). The measurements of wall thickness and dimension by MRI correlated well with those by echocardiography (r = 0.97, p less than 0.01). Ejection fraction calculated by MRI correlated significantly with that by cardiac catheterization (r = 0.82, p less than 0.05). We concluded that the left ventricular short-axis image in MRI is satisfactorily accurate for measuring wall thickness and dimension, and useful for evaluating the left ventricular ejection fraction.     

Visually estimated left ventricular ejection fraction by echocardiography is closely correlated with formal quantitative methods

BACKGROUND: Simpson ejection fraction, wall motion score index, atrioventricular (AV) plane displacement and fractional shortening are all established formal echocardiographic methods for the assessment of left ventricular systolic function. Visually estimated (eyeballing) ejection fraction may be considered somewhat more subjective, although shown to correlate well with radionuclide ventriculography. We aimed to explore if echocardiographic eyeballing ejection fraction is comparable to formal methods for the evaluation of left ventricular systolic function. METHODS: We assessed 89 consecutive patients after myocardial infarction or before coronary angiography. Eyeballing ejection fraction and wall motion score index were evaluated in the long-axis, short-axis and apical four- and two-chamber views. Simpson ejection fraction and AV plane displacement were assessed in the apical views. Fractional shortening was measured in the parasternal long-axis view. The respective systolic function measurements were in each patient made at different time points by a single investigator, masked to prior results. RESULTS: All formal methods correlated significantly with eyeballing ejection fraction (p<0.001): AV plane displacement, R=0.647; FS, R=0.684; four-chamber Simpson ejection fraction, R=0.857; biplane Simpson ejection fraction, R=0.898; and wall motion score index, R=0.919. CONCLUSION: Eyeballing ejection fraction correlated closely with all formal methods and the correlation coefficient improved with the reliability of the formal method. This finding is in concordance with prior studies, indicating that eyeballing ejection fraction may be the most accurate echocardiographic method for the assessment of left ventricular systolic function. Since it is readily and quickly performed, eyeballing ejection fraction could be used for routine echocardiography instead of formal methods.     

An evaluation of the left atrial/aortic root ratio in children with ventricular septal defect.

Echocardiograms were performed in 80 infants and children with isolated ventricular septal defect (VSD) who underwent cardiac catheterization. The pulmonary-to-systemic flow ratio (Qp/Qs) was correlated with the echocardiographic left atrial-to-aortic root diameter ratio (LA/Ao), and a relatively poor correlation (r = 0.62) was found. The end-systolic diameters of the left atrium and aorta at the level of the aortic root, obtained from lateral cineangiograms of 55 of the 80 patients, were compared with the corresponding echocardiographic dimensions. To assess the possible effect of transducer beam angulation upon the echocardiographic determinations, the angiographic measurements were made at 0 degrees position (perpendicular to the frontal plane) and at angles of 5 degrees, 10 degrees, 15 degrees and 20 degrees from zero, using the aortic root center as the point of intersection. The echocardiographic and angiographic aortic root measurements were comparable (r = 0.95), and the angiographically derived aortic diameter did not vary with different angle projections. However, the left atrial angiographic dimensions were significantly influenced by the angle of projection. We conclude that the echocardiographic LA/Ao ratio cannot reliably estimate the severity of the shunt flow in VSD.     

Quantitation of right ventricular volumes and ejection fraction by three-dimensional echocardiography in patients: comparison with magnetic resonance imaging and radionuclide ventriculography

Three-dimensional echocardiography (3DE) provides volumetric measurements without geometric assumptions. Volume-rendered 3DE has been shown to be accurate for the measurement of right ventricular (RV) volumes in vitro and in animal studies; however, few data are available regarding its accuracy in patients. This study examined the accuracy of 3DE for quantitation of RV volumes and ejection fraction (EF) in patients, compared to magnetic resonance imaging (MRI) and radionuclide ventriculography (RNV). Twenty patients underwent MRI, gated equilibrium RNV, and 3DE using rotational acquisition from both the transesophageal and transthoracic approaches. RV volumes and EF were calculated from the 3DE data using multislice analysis (true Simpson's rule). RV volumes calculated by MRI (end-diastolic volume (EDV) 109.4 +/- 34.3 mls, end-systolic volume (ESV) 59.6 +/- 31.0 mls, and EF 47.7 +/- 17.1%) agreed closely with 3DE. For transesophageal echocardiography, EDV was 108.1 +/- 29.7 mls (r = 0.86, mean difference 1.3 +/- 17.8 mls); ESV was 62.5 +/- 23.8 mls (r = 0.85, mean difference 2.8 +/- 15.1 mls); and EF was 43.2 +/- 11.7% (r = 0.84, mean difference 4.5 +/- 9.7%). For transthoracic echocardiography, EDV was 107.7 +/- 27.5 mls (r = 0.85, mean difference 1.6 +/- 18.2 mls); ESV was 59.7 +/- 22.1 mls (r = 0.93, mean difference 3.2 +/- 19.6 mls); and EF was 45.2 +/- 11.5% (r = 0.86, mean difference 2.0 +/- 9.4%). There were close correlations, small mean differences and narrow limits of agreement between RNV-derived EF (43.4 +/- 12.1%) and both transesophageal (r = 0.95 mean difference 0.2 +/- 3.7%) and transthoracic 3DE (r = 0.95, mean difference 1.8 +/- 5.4%). Three-dimensional echocardiography is a promising new method of calculating RV volumes and EF, comparing well with MRI and RNV. The accuracy of transthoracic 3DE was comparable to that of the transesophageal approach. Three-dimensional echocardiography has the potential to be useful in the clinical assessment of RV disorders.     

Myocardial performance index correlates with right ventricular ejection fraction measured by nuclear ventriculography

BACKGROUND: Assessment of right ventricular (RV) ejection fraction (EF) by two-dimensional echocardiography (2D ECHO) is practical but limited because of complex geometry of the RV. Techniques used for accurate measurement of RV EF are invasive or costly. However, derivation of 2D ECHO Doppler parameters to estimate RV function could be useful and inexpensive. METHODS: RV EF measured by nuclear ventriculography was compared with 2D ECHO estimates of myocardial performance index (MPI) and peak tricuspid annular systolic velocity (PTASV). Linear regression analysis and sensitivity analysis were used to analyze the data. RESULTS: RV EF measured by nuclear ventriculography correlated with MPI significantly (r =-0.55, P = 0.005) but not with PTASV (r = 0.09, P = 0.69). Using abnormal RV EF <45% measured by nuclear ventriculography, the sensitivity and specificity for MPI > 0.50 were 45.4% and 100%, respectively. The sensitivity and specificity of PTASV < or = 17.25 cm/sec in detecting abnormal RV EF were 100% and 35.4%. CONCLUSION: MPI greater than 0.50 indicates that RV function is abnormal and a value of PTASV > 17.25 cm/sec indicates normal RV function.     

The role of echocardiography for quantitative assessment of right ventricular size and function in adults with repaired tetralogy of Fallot

Background: Quantitative assessment of right ventricular (RV) systolic function by echocardiography is challenging in patients with congenital heart disease because of the complex geometry of the RV and the iatrogenic structural abnormalities resulting from prior cardiac surgeries. The purpose of this study was to determine the correla‐ tion between echocardiographic indices of RV systolic function and cardiac magnetic resonance imaging (CMRI) derived RV ejection fraction (RVEF) in adults with repaired tetralogy of Fallot (TOF).
Methods: Quantitative assessment of RV function was performed with RV tissue Doppler systolic velocity (RV s'), tricuspid annular plane systolic excursion (TAPSE), and fractional area change (FAC). These echocardiographic indices were compared to RVEF from CMRI performed on the same day as echocardiogram.
Results: Of 209 patients, the mean RV FAC was 39 ± 9%, TAPSE was 18 ± 4 mm, RV s' was 10 ± 2 cm/s, and RVEF was 40 ± 10%. There was a good correlation be‐ tween TAPSE and RVEF (r = 0.79, P < .001), good correlation between RV s' and RVEF (r = 0.71, P < .001), and modest correlation between FAC and RVEF (r = 0.66, P < .001). TAPSE < 17 mm effectively discriminated between patients with RV systolic dysfunc‐ tion defined as RVEF < 47% (sensitivity 81%, specificity 79%, area under the curve [AUC] 0.805). FAC < 40% was associated with RVEF < 47% (sensitivity 72%, specificity 63%, AUC 0.719). RV s' < 11 cm was associated with RVEF < 47% (sensitivity 83%, specificity 68%, AUC 0.798).
Conclusion: Despite the structural and functional abnormalities of the RV in patients with repaired TOF, quantitative assessment of RV systolic function by echocardiog‐ raphy is feasible and had good correlation with CMRI‐derived RVEF.