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Biomedical subjects

A Ganau

Publications and source records attributed to A Ganau.

67 records · Page 4Linked to original sources
PubMedDate not supplied

[Study on the medium normalized velocity of circumferential lengthening of the fiber using ultrasound. I. Evaluation of left-ventricular compliance].

The following parameters obtained by echocardiography have been measured in a group of normal subjects and in a group suffering from hypertrophic subaortic stenosis (IHSS): 1) speed of mitral valve protodiastolic closing (MVV); 2) circumferential lengthening speed of the fibre (MVCL) both standardized and otherwise. There is a good correlation between MVCL and MVV (P = 0.01 and 0.05). Since a low mitral valve closing rate is an indirect index for measuring ventricular compliance, the use of the MVCL can be considered valid for the same purposes. Using this it has in fact been possible to distinguish subjects with IHSS in which lower MVV is an index of reduced compliance, from normal subjects.

Cardiomyopathy, Hypertrophic↗
PubMedDate not supplied

[Study on the medium normalized velocity of circumferential lengthening of the fiber using ultrasound. II. Use of the construction of left-ventricle performance curves].

Telediastolic pressure and volume can readily be employed as expressions of sarcomere length when constructing ventricular performance curves for the normal heart. In pathological hearts, however, these parameters are rendered inadequate as a result of altered compliance, which means that diastolic lengthening of the muscle fibre cell must be determined from telediastolic stress and linear compliance, corrected for wall thickness (muscle fibre stretch, strain index). Ventricular performance curves were constructed for normal subjects and patients with hypertrophic subaortic stenosis, using the normalised mean rate of circumferential lengthening of the fibre as the expression of fiber strength. Comparison was made with the mean circumferential shortening rate and the ejection fraction as the expression of ventricular effort. It was found that both normal subjects and stenosis patients lay on the same curve, the latter acting low down through having short sarcomeres.

Cardiomyopathy, Hypertrophic↗
PubMedDate not supplied

[Use of normalized velocities in the echocardiographic evaluation of left ventricular performance].

The mean circumferential contraction rate of the myocardial fiber cell (Mvcf) and the ejection fraction (EF) are echocardiographic parameters commonly employed in the assessment of left ventricular performance. In cases where septal asynchonism due to fibrosis or bundle-branch block make their determination impossible, however, one is forced to use parameters obtained from movement of the posterior wall. Investigation of normal subjects and patients with idiopathic hypertrophic subaortic stenosis showed that the "normalized" systolic velocity of the posterior wall (Vpws) and the non-normalized mean velocity (PWV) closely fitted Mvcf and that Vpws offered a good fit with EF. It is suggested that a non-invasive way of obtaining sufficiently reliable data for the evaluation of cardiac performance is offered by these two parameters.

Cardiomyopathy, Hypertrophic↗
PubMedDate not supplied

[Standardized protodiastolic median velocity of the posterior wall (dpwV) used as an index of relaxation in the construction of left ventricular function curves].

The standardized mean protodiastolic speed of the posterior wall (Vpwd), non standardized speed (DEV) and maximum speed (DEVM) obtained with ultrasounds, are capable of distinguishing subjects with hypertrophic subaortic stenosis (IHSS), in whom there is a diminution in compliance, from normal subjects. As this compliance diminution is liable to limit fibrocell lengthening to the extent of its distension speed, the Vpwd has been used in the plotting of ventricular function curves in replacement of telediastolic volume (as an expression of fibre lengthening). An excellent correlation was found between Vpwd and mean speed of circumferential shortening of the fibre (Mvcf) and the ejection fraction (EF) used as indices of cardiac work. The comparison shows that the two groups lie on the same curve of ventricular function and that subjects with IHSS operate low down owing to the brevity of their sarcomeres. The Vpwd can thus be utilized as an indirect index of fibre length and in the plotting of left ventricular function curves.

Cardiomyopathy, Hypertrophic↗
PubMedDate not supplied

[Normalized median velocity of circumferential fiber lengthening studied with ultrasonics. III. Comparison with the normalized protodiastolic median "velocity" of the posterior wall].

Both mitral valve closing speed (MVV) and the mean standardized circumferential lengthening of the myocardial fibrocell (MVCL), between which a good correlation exists, may be used as indirect indices of ventricular compliance. These two indices have been compared with those obtained echocardiographically from the movement of the posterior wall of the ventricle in a group of normal subjects and in a group suffering from hypertrophic subaortic stenosis (IHSS). The comparison between MVCL and mean standardized speed of protodiastolic prolapse of the posterior wall (Wpwd) was fairly significant (P=0.01); that between MVCL and mean speed of protodiastolic prolapse of the posterior wall (DEV) was only slightly significant (P=0.05) or was not significant at all; that between MVCL and the maximum speed of protodiastolic release (DEVM) was slightly significant (P=0.05). Although the correlation between MVV and the various indices obtained from the movement of the posterior wall (DEV, DEVM, Vpwd) were quite significant (P=0.01), it is considered that Vpwd is preferable as an indirect index of ventricular compliance. As it is capable of distinguishing subjects with IHSS from normal subjects inthose cases in which the movement of valvular peaks, modified or impeded by inflammatory or fibrotic processes does not a-low MVV to be measured, we think Vpwd can be usefully employed as it can in all those circumstances in which it is impossible to measure MVCL owing to alterations to normal septal synchronism (infarction and fibrosis of the septum, branch blocks, etc.).

Aortic Stenosis, Subvalvular↗