PubMed Health⌕ Search

Biomedical subjects

O Rodevand

Publications and source records attributed to O Rodevand.

6 recordsLinked to original sources
PubMed1999

Diastolic flow pattern in the normal left ventricle.

OBJECTIVES: This study sought to clarify the diastolic flow pattern in the normal left ventricle. BACKGROUND: During left ventricular filling, basally directed (retrograde) velocities are seen in the outflow compartment. These velocities may represent blood returned from the apical region or a shortcut at a more basal level. METHODS: Left ventricular flow patterns were identified in 18 healthy individuals (age 47 +/- 12 years) with the use of high frame-rate two-dimensional color Doppler and color M-mode Doppler echocardiography techniques. Intraventricular velocities were measured with single pulsed Doppler at 3 levels in both inflow and outflow compartments (posterolateral and anteroseptal parts of the left ventricle). RESULTS: During early transmitral flow acceleration, all intraventricular velocities were directed towards the apex. However, after peak early and late inflow velocities and during diastasis, retrograde velocities were identified in the outflow compartment. These retrograde velocities occurred earlier, and were higher, at the level of the deflected anterior mitral leaflet tip compared with more apical levels (P <.001). A velocity pattern was established, consistent with early intraventricular vortex formation behind both mitral leaflets. The vortex adjacent to the anterior leaflet subsequently enlarged to include a major part of the left ventricle. CONCLUSION: Uniform diastolic flow patterns were identified in the normal left ventricles. The findings suggest that both early and late diastolic filling start with an initial motion of a fluid column, succeeded by vortex formation, which explains retrograde flow in the outflow compartment.

Adult↗
PubMed1999

Reversal of intraventricular flow propagation during isovolumic relaxation: A marker of anterior wall dysfunction.

BACKGROUND: Myocardial infarction induces left ventricular (LV) wall motion abnormalities during isovolumic relaxation (IVR) and may potentially alter intraventricular flow during this period. This study evaluated whether 2-dimensional color Doppler measurements of intraventricular flow during IVR were able to identify LV dysfunction caused by coronary artery disease. METHODS: Patients with single-vessel coronary artery disease and posterior wall infarction (21 patients) or anterior wall infarction (27 patients) were included. Eighteen healthy persons served as a control group. LV function was examined by 2-dimensional echocardiography, 2-dimensional color Doppler, and pulsed Doppler techniques. RESULTS: All normal persons (23.6 +/- 10.9 cm/s) and patients with posterior infarction (19.6 +/- 9.3 cm/s) had flow propagation towards LV apex during IVR. Patients with anterior wall infarction had reversed flow direction (-12.2 +/- 8.7 cm/s, P <.001). The echocardiographic wall motion score index of the 4 apical segments correlated well with flow velocities (r = -0.78, P <.001). CONCLUSION: Reversed flow propagation during IVR may become a sensitive clinical marker of regional ischemia.

Analysis of Variance↗
PubMed1998

Left ventricular volumes assessed by different new three-dimensional echocardiographic methods and ordinary biplane technique.

UNLABELLED: Three-dimensional (3D) echocardiography may overcome the problems with inadequate accuracy and reproducibility of 2D volume measurements of the left ventricle. AIMS: To establish the in vitro accuracy and reproducibility of two new methods for 3D echocardiographic volume determination as compared to biplane measurements. METHODS: Validation of volume measurements by a multiplane 3D method was performed on asymmetric latex phantoms (n = 8, true volumes 45-304 ml) using rotational acquisition of 90 image planes. Porcine agarose-filled asymmetrical left ventricles (n = 7, true volumes 34-280 ml) were measured by the same multiplane 3D method based on images acquired by probe rotation axis perpendicular (A) and parallel (B) to the ventricular long axis. Ventricular volumes were also obtained by a simplified 3D system using only the three standard apical views (C) and by the ordinary biplane Simpson's method (D). RESULTS: On latex phantoms systematic deviation from true volumes by multiplane 3D was less than 2%, and 95% variability of individual measurements from this mean was +/- 4.9%. For accuracy on left ventricles, systematic bias was small with all the methods (< 5%), but 95% variability of individual measurements was +/- 9.0%, 15.4%, 18.8% and 41.3% of true volumes for methods A-D respectively. Corresponding results in the same range were obtained for inter- and intraobserver variability. CONCLUSION: Individual in vitro volume estimates of left ventricles are of similar quality using apical multiplane or apical triplane 3D echocardiography. Both methods were superior to the ordinary apical biplane method, but inferior to multiplane 3D method with the probe directed perpendicular to the ventricular long axis.

Animals↗
PubMed1997

Left ventricular mass assessed by three-dimensional echocardiography using rotational acquisition.

BACKGROUND: The reproducibility of left ventricular (LV) mass measurement by two-dimensional (2-D) echocardiography is inadequate for individual assessments. HYPOTHESIS: This study was undertaken to evaluate the potential of LV mass determination with a new three-dimensional (3-D) echocardiographic method compared with 2-D measurements. METHODS: Porcine agarose-filled left ventricles (n = 15, true mass 61-511 g) of different shapes were measured by a multiplane 3-D method based on 90 images acquired by probe rotation axis (1) perpendicular and (2) parallel to the ventricular long axis ["parasternal" (the left sternal border was not present as a reference point in this study) and apical views]. Mass was also obtained using (3) the biplane truncated ellipsoid and (4) area-length methods, as well as (5) the modified cube formula. Five hearts were not analyzed with the apical 3-D technique because of insufficient image quality. RESULTS: Systematic deviation from true mass was small with all methods (< 5.3%). Accuracy, expressed as 1 standard deviation of individual estimates around this systematic bias, was 7.7, 13.6, 8.2, 11.9, and 11.9% of true mass for the methods 1-5, respectively. Interobserver reproducibility, expressed as the coefficient of variation, was 4.7, 8.8, 8.1, 8.9, and 9.4% for the same methods. CONCLUSION: Limits for individual accuracy and reproducibility of LV mass estimates are nearly doubled using apical compared with "parasternal" 3-D echocardiography in vitro. A main advantage of "parasternal" 3-D compared with 2-D LV mass estimates is better reproducibility, but at the expense of greater time consumption. Apical 3-D technique is not superior to simpler 2-D methods based on "parasternal" short axis imaging.

Animals↗
PubMed1993

Left ventricular hypertrophy and myocardial ischaemia in hypertension: the THAMES Study.

A multicentre epidemiological study to detect the prevalence of myocardial ischaemia in hypertensive left ventricular hypertrophy (LVH) was performed in 188 asymptomatic male hypertensives (131 treated). The mean age was 55 (range 40-82) years with blood pressure (BP) > or = 160/100 mmHg or a systolic BP > or = 180 mmHg. The participants were screened with echocardiography, and left ventricular hypertrophy (LVH), defined as LV mass index (LVMI) > or = 130 g.m-2, was found in 127 (68%), of whom 95 were on antihypertensive treatment. Patients with LVH underwent a maximal bicycle ergometer exercise test and significant ST depression, indicating possible stress-induced ischaemia, was found in 29 men (23%). These subjects were subjected to exercise thallium-201 scintigraphy, which was normal in 14 but showed reversible perfusion defects in 15. Thus, a high prevalence of LVH (70%) was detected in male hypertensives selected only on age and BP. In addition, although chest pain on exertion excluded patients from entry, a substantial portion had signs of ischaemia (23% on exercise ECG alone, and in 52% confirmed by thallium scan). The prevalence of these risk factors should be considered when evaluating hypertensive patients.

Adult↗