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PubMed2000

Validity and reproducibility of echocardiographic measurement of left ventricular ejection fraction by acoustic quantification with tissue harmonic imaging technique.

The tissue harmonic imaging technique can enhance detection of the cardiac endocardial border. When combined with an acoustic quantification (AQ) method, an improvement of accuracy and reproducibility of real-time measurement of left ventricular (LV) function might be expected. However, few data exist regarding the measurement of LV function by AQ with the harmonic imaging technique. Therefore, we evaluated the validity and reproducibility of AQ measurement of LV ejection fraction with or without harmonic imaging technique. A total of 50 patients (mean age 58 +/- 10 years) who underwent left ventriculography were included in our study. The LV end-diastolic and end-systolic volumes by ventriculography were 131 +/- 52 mL and 72 +/- 43 mL, respectively, and were underestimated by both conventional (70 +/- 32 mL and 36 +/- 25 mL) and harmonic (67 +/- 30 mL and 34 +/- 22 mL) AQ obtained in the apical 4-chamber view. The calculated ejection fraction by ventriculography was 0.49 +/- 0. 11 and correlated with that by conventional AQ (0.51 +/- 0.11; y = 0. 72x + 0.152; r = 0.73). This was a marked improvement when compared with the ejection fraction by harmonic AQ (0.50 +/- 0.11; y = 0.89x + 0.065; r = 0.91). Interestingly, interobserver and intraobserver variabilities of conventional AQ, which were 15.6% and 8.6%, respectively, were much improved by harmonic AQ (8.9% and 4.5%, respectively). These results indicate the feasibility of real-time measurement of LV ejection fraction by harmonic imaging, although absolute LV volume can be underestimated even by this technique.

Aged↗
PubMed1981

Radionuclide ejection fraction: a technique for quantitative analysis of motor function of the human gallbladder.

A new noninvasive technique for the measurement of the gallbladder evacuation quantitatively is described. By using a radioactive bile marker [99mTc]HIDA, the evacuation of the gallbladder is measured nongeometrically in terms of ejection fraction (fractional bile volume emptied from the gallbladder) and ejection rate (dv/dt). The counts and volume in an in vitro gallbladder phantom under pinhole collimator geometry show a linear relationship (r = 0.998) enabling the replacement of gallbladder bile volume by bile counts before and after evacuation. The counts ejection-fraction shows a high degree of correlation (r = 0.998) with the measured-volume method. The movement of the gallbladder during respiration does not effect the measurement of ejection fraction. The technique allows simultaneous imaging and quantitation, and it is highly reproducible, carrying an interobserver and reproducibility mean error of 5%. This technique is suitable for studying the motor functions of the gallbladder and the effects of various pharmacologic agents on its evacuation. The clinical usefulness of the technique requires further testing.

Adult↗
PubMed2026

Combined high-fat, high-sucrose diet and streptozotocin treatment induces cardiometabolic heart failure with preserved ejection fraction in mice.

Diabetes is associated with an increased incidence of heart failure with preserved ejection fraction (HFpEF), but the underlying mechanisms are poorly understood. A shortage of mouse models reflecting the diverse HFpEF pathophysiology contributes to this inadequate understanding of disease mechanisms. We conducted a comprehensive analysis of a nongenetic, inducible type 2 diabetes mellitus (T2DM) mouse model about its suitability as a preclinical model of cardiometabolic, diabetes-induced HFpEF. T2DM was induced in C57Bl/6 mice by a high-fat/high-sucrose diet and a low-dose streptozotocin (DIO-STZ). Cardiac function was assessed in vivo by echocardiography and left ventricular catheterization and in vitro using the isolated perfused heart. Structural, molecular, and bioenergetic disturbances were analyzed by immunohistochemistry, RNA-seq, qPCR, Western blot, and extracellular flux analysis of myocardial tissue. Blood glucose, fatty acids, and ketone body levels were elevated, and insulin levels were reduced in DIO-STZ compared with chow. DIO-STZ mice showed an HFpEF phenotype with reduced cardiac output, end-diastolic volume, and increased filling pressure. No differences in myocardial fibrosis or in vitro stiffness were detected between DIO-STZ and chow. RNA-Seq pointed toward disturbances in lipid and ketone metabolism. Extracellular flux analysis revealed increased fatty acid oxidation capacity without differences in glucose metabolism. No general mitochondrial dysfunction was observed, but a reduced capacity for β-hydroxybutyrate oxidation. The diabetic DIO-STZ mouse model showed a pronounced functional HFpEF phenotype with underlying mechanisms that remarkably differ from other HFpEF models, making the DIO-STZ model a relevant extension of the range of HFpEF mouse models, especially for investigating molecular mechanisms or therapeutic interventions in diabetes-associated HFpEF.NEW & NOTEWORTHY Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome whose pathophysiological mechanisms are incompletely understood, potentially due to a lack of preclinical models reflecting the broad range of pathophysiological aspects. We describe a diabetic DIO-STZ mouse model showing a pronounced HFpEF with underlying mechanisms that remarkably differ from other HFpEF models, making this model a relevant extension of the range of HFpEF models, especially for investigating molecular mechanisms or therapeutical interventions in diabetes.

Animals↗
PubMed1998

Prognostic significance of coronary flow reserve on left ventricular ejection fraction in cardiac transplant recipients.

BACKGROUND: Cardiac allograft vasculopathy is a common phenomenon in epicardial and microvascular vessels. Intramyocardial vessel disease may lead to small, stellate infarcts. The present study tested the impact of microvascular vasomotor function on changes in left ventricular systolic function in the long-term follow-up after cardiac transplantation. METHODS: Seventeen consecutive cardiac transplant patients, 40+/-21 months after cardiac transplantation, without angiographically visible cardiac allograft vasculopathy and without episodes of acute rejection were included in the study. Coronary microvascular reactivity was assessed by the endothelium-dependent stimulus acetylcholine (50 microg i.c.) and by the endothelium-independent stimulus dipyridamole (0.56 mg/kg i.v.) utilizing an Doppler catheter. Radionuclide ventriculography was performed at the time of coronary flow measurement and repeated 2 years later to correlate changes in left ventricular ejection fraction with the coronary flow reserve measurement 2 years previously. RESULTS: There was a statistically significant correlation between endothelium- independent coronary flow reserve to dipyridamole and changes in ejection fraction at rest (r=0.59; P < 0.01) and during exercise (r=0.48; P < 0.05). Twenty-four months later, patients with a coronary flow reserve to dipyridamole < 2.5 showed a significant decline in ejection fraction during exercise (-7 +/- 5%) compared to patients with a coronary flow reserve > 2.5 (1.1+/-5%; P=0.003). Coronary flow reserve to acetylcholine was not correlated with a reduced ejection fraction during exercise. CONCLUSIONS: Endothelium-independent microvascular dysfunction has prognostic importance for deterioration of left ventricular function in cardiac transplant recipients without angiographically visible coronary artery stenoses. These results reinforce the concept that microvascular and epicardial vessel disease after transplantation are two distinct entities with different functional consequences.

Adolescent↗
PubMed2006

QGS ejection fraction reproducibility in gated SPECT comparing pre-filtered and post-filtered reconstruction.

INTRODUCTION: The aim of this investigation was to compare the QGS determined functional parameters using pre-filtering to that using post-filtering in the gated myocardial perfusion single photon emission computed tomography (SPECT) reconstruction process. METHODOLOGY: A total of 25 patient files were examined, each with both a gated rest and gated stress study, and were reconstructed using two strategies. The first employed pre-filtering with a Butterworth low pass filter (order 4.0 and cut-off 0.21) and the second employed post-filtering with a Butterworth low pass filter (order 5.0 and cut-off 0.21). Following reconstruction and reorientation, gated short axis slices were evaluated with QGS software. RESULTS: The mean ejection fraction for the post-filtered data was 49.5% (95% CI, 45.8-53.1%) and for the pre-filtered data was 54.8% (95% CI, 51.4-58.1%). Excellent correlation was demonstrated between the pre- and post-filtered ejection fractions with a correlation coefficient of 0.964. The mean difference between matched pairs of pre- and post-filtered ejection fraction data was 5.3% (95% CI, 4.3-6.3%). The match pair t-test demonstrated a statistically significant difference between matched pairs (P<0.0001) and a statistically significant difference was shown between the means (P=0.005). CONCLUSION: The impact of performing pre-filtering on data in the reconstruction process is significant with a 5.3% increase in the calculated ejection fraction over post-filtering. Clearly, this has the potential to undermine diagnostic and prognostic roles of functional parameters.

Algorithms↗
PubMed1993

Feasibility of measuring relative right ventricular volumes and ejection fraction with implantable rhythm control devices.

Ejection fraction (EF), the ratio between stroke volume (SV) and end-diastolic volume (EDV), is a valuable contractility indicator. Unlike SV, the Frank-Starling effect is automatically compensated in the calculation of EF. It was the aim of this study to evaluate the physiological behavior of impedance derived measurements of relative right ventricular (RV) volumes and EF, obtained with standard pacing leads. Seven patients were evaluated at the time of pacemaker implant or replacement. Since no absolute standard of comparison was available for RV volumes, the value of the measurements was assessed by observing their behavior under cardio-circulatory challenges. A 2.5-kHz carrier was fed to the ring and tip electrodes of standard bipolar pacing leads and the resulting voltage was digitized and stored. The peak-to-peak voltage (PPV) of the carrier at the time of QRS was used as EDV, and the largest PPV as end-systolic volume (ESV). Relative SV was the difference between EDV and ESV, and EF = SV/EDV x 100. Pacing was used to reduce EDV, and the effect of contractility was tested with isometric hand grip, recumbent leg exercise, or isoproterenol drip. Only minimal changes in EF were noted during incremental pacing; relative SV and EDV decreased as expected; and EF increased significantly during contractility challenges. A high correlation coefficient was observed between EDV and SV changes induced by incremental pacing at rest (r values from 0.62 to 0.98, P from < 0.01 to 0.001). The study revealed that impedance volumetry, utilizing conventional bipolar pacing leads, yields useful hemodynamic data related to EDV, ESV, and EF. Given the simplicity of the method, it is reasonable to conclude on the feasibility of using said impedance derived hemodynamic parameters in implantable rhythm control devices.

Adult↗
PubMed2003

Impact of tissue harmonic imaging in patients with distorted left ventricles: improvement in accuracy and reproducibility of visual, manual and automated echocardiographic assessment of left ventricular ejection fraction.

AIMS: The aim of this study was to assess the incremental value of tissue harmonic imaging vs conventional echocardiography for evaluating left ventricular ejection fraction by manual and automated quantitation as well as visual estimation in patients with distorted left ventricles. METHODS AND RESULTS: In 25 patients unselected for image quality and with distorted left ventricles who underwent a nuclear study, digital cineloops of standard apical views were acquired by both tissue harmonic imaging and conventional echocardiography and sent to six observers for analysis of visual and quantitative left ventricular ejection fraction. Tissue harmonic imaging improved both the correlation and agreement of all echo techniques with nuclear measures, compared with conventional echocardiography echo, reducing standard errors (SE) to below 10%: for the visual estimate SE=7.5%, for manual tracing SE=6.3% and for automated tracing SE=8%. Tissue harmonic imaging decreased inter-observer variability compared with conventional echocardiography echo for both visual assessment (12.4% vs 18.4%, P<0.05) and quantitative measures (for manual tracing, 8.2% vs 11.8%, P<0.05; for automated tracing, 7.8% vs 16.8%, P<0.05). CONCLUSIONS: In patients with distorted left ventricles unselected for image quality, tissue harmonic imaging improves accuracy and reproducibility of both visual and quantitative echocardiographic assessment of left ventricular ejection fraction. In particular, it promotes automated quantitation by reducing its high standard error into a clinically reasonable range.

Aged↗
PubMed2004

Accuracy of measurement of left ventricular volume and ejection fraction by new real-time three-dimensional echocardiography in patients with wall motion abnormalities secondary to myocardial infarction.

Three-dimensional echocardiography is an ideal tool for the measurement of left ventricular (LV) volume because no geometric assumptions about LV shape are needed. The introduction of new real-time 3-dimensional echocardiography (RT3DE) has allowed rapid acquisition of a 3-dimensional dataset with good image quality. The purpose of this study was to examine the accuracy of RT3DE for the measurement of LV volume and ejection fraction in patients with wall motion abnormalities by using quantitative gated single-photon emission computed tomography (QGSPECT) as a reference standard. The study population consisted of 25 consecutive patients with wall motion abnormalities who underwent LV volume measurement by 2-dimensional echocardiography and by QGSPECT. LV volume and ejection fraction by RT3DE were measured offline by using the average rotation method. In 23 of 25 patients (92%), it was possible to measure 3-dimensional volume with RT3DE. RT3DE correlated well with QGSPECT in the measurement of end-diastolic volume and end-systolic volume (r = 0.97, mean difference 3.4 ml; r = 0.98, mean difference 2.0 ml, respectively), 2-dimensional echocardiography also correlated with QGSPECT but underestimated LV volume (r = 0.98, mean difference 21.1 ml; r = 0.98, mean difference 15.6 ml, respectively). Ejection fraction obtained by RT3DE had better agreement with that obtained by QGSPECT than that obtained by 2-dimensional echocardiography (r = 0.92, mean difference -0.2%; r = 0.89, mean difference -2.7%, respectively). RT3DE allows convenient and accurate estimation of LV volume and ejection fraction in patients with wall motion abnormalities.

Adult↗
PubMed2004

Left ventricular ejection fraction calculation from automatically selected and processed diastolic and systolic frames in short-axis cine-MRI.

The calculation of the left ventricular ejection fraction (LVEF) is dependent upon the accurate measurement of diastolic and systolic left ventricular volumes. Although breath-hold cine magnetic resonance imaging (MRI) allows coverage of the whole cardiac cycle with an excellent time resolution, many authors rely on the visual selection of diastolic and the systolic short-axis slices in order to reduce the postprocessing time. An automatic method was developed to detect the endocardial contour on each image, allowing an automatic selection of the systolic frame. The calculated ejection fraction was compared with radionuclide ventriculography (RNV). Sixty-five patients were examined using an electrocardiogram (ECG)-gated gradient echo sequence. Among these examinations, manual and automatic processing with MRI were compared when the time of the systolic frame concorded. Good correlations have been found between the automatic MRI approach and RNV, and between manual and automatic processing on MRI alone. The results show that the automatic determination of the ejection fraction is feasible, and should constitute an important step toward a larger acceptance of MRI as a routine tool in heart disease imaging. One major benefit of using automatic postprocessing is that it may eliminate the visual choice of the systolic frame, inaccurate in more than 50% of the studied patients.

Adult↗
PubMed1984

[Non-invasive determination of left ventricular ejection fraction using a mobile ECG-triggered scintillation measuring probe. Comparison of cineventriculography, echocardiography and radionuclide ventriculography].

In 29 unselected patients, the left ventricular ejection fraction was evaluated using a mobile ECG-gated scintillation probe (Nuclear Stethoscope) after in vivo labeling of the erythrocytes with 15 mCi technetium-99m. To validate the method, the Nuclear Stethoscope measurements were correlated to the results of: 1. Single-plane contrast cineventriculography in the right and left anterior oblique projections (RAO, LAO), 2. Radionuclide ventriculography with a gamma camera computer system, 3. Two-dimensional echocardiography from the apical two- and four-chamber views. The ejection fraction measured by the Nuclear Stethoscope showed a close correlation to the values obtained by cineventriculography in the RAO projection (r = 0.748) and radionuclide ventriculography (r = 0.785). In this group of unselected patients, the correlations with the results of two-dimensional echocardiography were poor (r = 0.451 and 0.557). Cineventriculographic findings and radionuclide ventriculography correlated well (RAO: r = 0.786; LAO: r = 0.758). The Nuclear Stethoscope provides a simple, reliable, and noninvasive method for measuring ventricular ejection fraction. Ongoing studies indicate that the Nuclear Stethoscope is a valid method even at a lower dose of 5 mCi technetium-99m.

Cardiac Output↗
PubMed1989

Measurement of left ventricular ejection fraction and volumes with three-dimensional reconstructed transesophageal ultrasound scans: comparison to radionuclide and thermal dilution measurements.

A transesophageal, ultrasonic cardiac imaging probe was built that incorporated a mechanism for changing the angle of the imaging plane of a conventional phased array in a precise and known manner. This probe was used to acquire an angular spatial sequence of two-dimensional images of the left ventricular cavity over a series of cardiac cycles by sweeping the imaging plane through it stepwise. The endocardial borders of these images were manually outlined off-line and the application of a three-dimensional reconstruction algorithm was then used to compute the left ventricular end-diastolic and end-systolic volumes and ejection fraction. A study was conducted with seven anesthesized dogs to compare ultrasonic determinations by this method with determinations and measurements made using radionuclide and thermal dilution methods. Comparison of 33 ejection fractions, measured by the ultrasonic volume method and by the gated blood pool radionuclide approach, yielded a correlation coefficient of 0.87 and a standard error of the estimate of 5.7% measured over a range of 10% to 58% (average, 40%). Comparison of the ultrasonically measured volumes with those calculated from stroke volume (derived from thermal dilution cardiac output measurement) and ejection fraction (measured by radionuclide technique) produced a correlation coefficient of 0.92 and a standard error of the estimate of 10.3 mL over a range of 18 to 130 mL (average, 56 mL). The accuracy of volume and ejection fraction measurements with this new ultrasonic method seems comparable to that of other currently used clinical approaches such as radionuclide and angiography.

Animals↗
PubMed1984

Cross sectional echocardiographic assessment of left ventricular volume and ejection fraction in patients with tetralogy of Fallot. Comparison with biplane angiographic measurements.

To evaluate the usefulness and accuracy of calculating left ventricular volume and ejection fraction from cross sectional echocardiograms in patients with tetralogy of Fallot, 28 patients were studied within 24 hours of cineangiography. Indexed end diastolic and end systolic volumes were calculated from three different paired echocardiographic projections: (a) the two and four chamber views from the apical impulse window, (b) the parasternal long axis view and the subxiphoid long axis view, and (c) the four chamber view and short axis precordial views at mitral and papillary muscle level. Volumes were calculated in five different ways using three different algorithms (area length, Simpson's rule, the Parisi formula). The results were compared with data obtained from biplane angiograms using Graham's formula. The correlation varied with the algorithm used: the best results were obtained with the area length method using the parasternal long axis view and the sub-xiphoid view. The correlation was less accurate for the ejection fraction. The second best correlation was obtained with the area length method using the two and four chamber apical views; the other correlations were less satisfactory. Thus these results show that left ventricular volumes can be accurately assessed by cross sectional echocardiography in children with tetralogy of Fallot and that the ejection fraction can be satisfactorily estimated. The results depend on careful gain setting and precise demonstration of the left ventricular endocardium, which is best seen in the sub-xiphoid and long axis views.

Adolescent↗
PubMed1993

The value of the QRS scoring system in assessing regional and global left ventricular ejection fraction early after myocardial infarction.

In 71 patients with a myocardial infarction (MI) (anterior in 27, inferior in 44 patients) global (GEF) and regional (REF) left ventricular ejection fractions were determined by radionuclide ventriculography and estimated from a 12 lead electrocardiogram (ECG), using Selvester's QRS score, during the early phase of a MI (15 to 21 days following MI). Global ejection fractions determined by radionuclide ventriculography and from ECG using Palmeri's method were: for all MI 40.8 +/- 12.6% vs 39.6 +/- 11.4%; in the group of anterior MI 32.0 +/- 10.0% vs 30.0 +/- 9.7% and in the group of inferior MI 48.9 +/- 12.0% vs 45.1 +/- 8.2%. A good correlation was found between global ejection fractions determined by radionuclide ventriculography and ECG, as well as between radionuclide GEF and ECG score. A weaker correlation was found between radionuclide GEF and enzymes among all MIs and in the group of anterior MI, while in the group of inferior MI this correlation was insignificant. The analysis of REF determined by radionuclide ventriculography and ECG showed the greatest abnormalities in the infarct region, but in the group of anterior MI, dysfunction was present in the whole left ventricle. The comparison of infarct-related REF derived from radionuclide ventriculography, with the QRS score showed a significantly higher correlation than the comparison with enzymes. ECG estimation of REF from a modified Palmeri's equation showed a better correlation with radionuclide REF than did GEF derived from the standard Palmeri's equation: anterior MI; r = 0.90 vs r = 0.82, inferior MI; r = 0.84 vs r = 0.69, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1978

[Nuclear medical determination of the ejection fraction and the regional wall movements of the left ventricle].

Left ventricular ejection fraction was determined in 114 patients by radionuclide and contrast angiocardiography. The correlation coefficient (r) amounted to 0.66. Exclusion of patients with arrhythmias and with a difference in heart rate exceeding 15 beats per minute between the two determinations of the ejection fraction increased r to 0.80 (61 patients). In patients with coronary artery disease and cardiomyopathies (n = 35), r was higher (0.88) than in patients (n = 26) with acquired valve disease or congenital heart disease (0.60). Comparison of first pass radionuclide angiocardiography and gated blood pool scanning with contrast angiocardiography in 19 patients elicited an r-value of 0.82 for the first pass method and of 0.31 for gated blood pool scanning. Visual assessment of local wall motion by gated blood pool scanning in 15 patients showed agreement with cineangiographically quantitated segmental motion (normo-, hypo- or a-kinesis) in 50 of 60 (= 83%) evaluated segments.

Angiocardiography↗
PubMed2000

Feasibility and accuracy of left ventricular volumes and ejection fraction determination by fundamental, tissue harmonic, and intravenous contrast imaging in difficult-to-image patients.

The need to enhance the echocardiographic determination of left ventricular ejection fraction is greatest in patients with suboptimal images. Intravenous contrast (CON) and tissue harmonic imaging (THI) are 2 important methods for enhancing endocardial border definition. However, the comparative feasibility and accuracy of THI and contrast-enhanced power harmonic imaging in difficult-to-image patients have not been examined. We assessed the comparative accuracy of THI and CON in determining EF and ventricular volumes in patients with suboptimal fundamental images. We demonstrated that CON is feasible and exhibits a greater correlation with ejection fraction and ventricular volumes determined by radionuclide angiography (standard of comparison) than THI in this difficult-to-image population, with no reported side effects. For both ejection fraction and ventricular volumes, the observer variability was least for CON, intermediate with THI, and greatest for fundamental imaging.

Adult↗
PubMed1991

Measurement of left ventricular ejection fraction using gated 99mTc-sestamibi myocardial planar images: comparison to contrast ventriculography.

Using the new myocardial perfusion agent 99mTc-sestamibi and multigated acquisition on a nuclear medicine gamma camera, the left ventricular ejection fraction (LVEF) was derived in 13 patients with coronary artery disease (CAD). Cross-sectional activity profiles were used to measure the left ventricle from end-diastolic and end-systolic images. Several different geometric methods were then utilized to derive ejection fractions from the nuclear data. Comparison of the resultant ejection fractions to those obtained from contrast ventriculography showed significant correlation for all geometric methods (P less than 0.01, Sy X x = 6.2 to 9.6). We conclude that in patients with CAD one or more of these simple geometric methods can provide a useful estimate of the LVEF when performing 99mTc-sestamibi multigated myocardial perfusion imaging.

Adult↗
PubMed1992

Excessive vasoconstriction in rheumatic mitral stenosis with modestly reduced ejection fraction.

OBJECTIVES: The primary hypothesis examined was that underfilling due to inflow obstruction accounts for modestly depressed ejection performance in mitral stenosis. Having found little evidence to support this hypothesis, we sought to determine other factors that might differentiate patients with different levels of ejection performance. METHODS: Ventricular load and performance were compared in two groups of patients before and immediately after successful balloon valvuloplasty that was not complicated by mitral regurgitation: those in whom prevalvuloplasty ejection fraction was > or = 0.55 (group I, n = 10) and those in whom it was < 0.55 (group II, n = 11). RESULTS: Before valvuloplasty, mitral valve area was less in group II (0.65 cm2) than in group I (0.84 cm2, p = 0.02), but end-diastolic pressure (12 vs. 12 mm Hg in group I), end-diastolic wall stress (46 vs. 44 kdynes/cm2 in group I) and end-diastolic volume (152 vs. 150 ml in group I) were not less in group II, nor were these variables significantly reduced compared with those of a normal control group. In group II, end-systolic volume was larger (77 vs. 55 ml in group I, p = 0.001) and cardiac output was less (3.1 vs. 3.6 liters/min in group I, p = 0.03), possibly owing to higher systemic vascular resistance (2,438 vs. 1,921 dynes.s.cm-5 in group I, p = 0.05) and end-systolic wall stress (273 vs. 226 kdynes/cm2 in group I, p = 0.06), although mean arterial pressure in the two groups was similar (91 vs. 84 mm Hg in group I, p = 0.22). Group II patients also had higher values for pulmonary vascular resistance (712 vs. 269 dynes.s.cm-5 in group I, p = 0.03) and mean pulmonary artery pressure (47 vs. 29 mm Hg in group I, p = 0.02) despite similar values for mean left atrial pressure (20 vs. 18 mm Hg in group I, p = 0.35). After valvuloplasty, mitral valve area increased by 2.5- and 3-fold, respectively, in group I (to 2.1 cm2) and group II (to 2.0 cm2). Modest increases in left ventricular end-diastolic pressure, end-diastolic stress and end-diastolic volume (+9%) after valvuloplasty were statistically significant only for group II. End-systolic wall stress did not decline in either group II (281 kdynes/cm2) or group I (230 kdynes/cm2), and ejection fraction failed to increase significantly (0.49 to 0.51 for group II and 0.62 to 0.61 for group I) after valvuloplasty. Contractile performance estimated with a preload-corrected ejection fraction-afterload relation was within or near normal limits in all 19 patients in whom it was assessed. CONCLUSIONS: Excessive vasoconstriction may account for the higher afterload, lower ejection performance and lower cardiac output observed in a subset of patients with mitral stenosis because contractile dysfunction could not be detected and left ventricular filling--which was not subnormal despite severe inflow obstruction--improved only modestly after valvuloplasty.

Adolescent↗
PubMed1992

[Ventricular ejection fraction in oxygen therapy of patients with pulmonary tuberculosis].

Radionuclide study of ejection fraction of the right heart ventricle was carried out in lung tuberculosis patients with respiratory insufficiency and cor pulmonale. Oxygen therapy was found to promote reduction of right ventricle heart failure in effective treatment of lung tuberculosis. The greatest reduction of heart failure was recorded in cases where oxygen therapy was combined with cardiac glycosides. As the tuberculosis process progresses, oxygen therapy does not decrease right ventricle heart failure. The treatment by antibacterial agents alone without using oxygen does not lead to the rise of ejection fraction of the right ventricle of the heart.

Antitubercular Agents↗