[Elasticity and viscoelasticity in the circulatory system. IV. Diastolic filling of the left ventricle].
This paper studying diastolic left ventricular and myocardial elastic and viscoelastic properties, some of its consequences and its quantification, constitutes the fourth part of a review on circulatory system elasticity and viscoelasticity. The ventricular elastic and viscoelastic properties depend on myocardial ones and on chamber shape and dimensions. Thus it is often necessary to quantify the ventricular and the myocardial properties separately. As an approximation, the viscoelastic effects during diastole can be neglected and the elastic properties deduced from data obtained over the entire filling; however, these properties can be quantified rigorously only when using viscoelastic models. Another method of exact quantification is based on diastatic data alone; the latter do not reflect significant viscoelastic effects because they correspond to a period in which deformation rate is very slow. This study includes several Pathophysiological applications: some alterations in ventricular elastic properties induced by the pericardium are analysed and deviations from normal ventricular and myocardial diastolic properties caused by primary angina pectoris, by effort angina pectoris and by hypertrophy due to volume and pressure overload are examined. The basic Physical and Biophysical concepts essential to the better phenomena understanding are exposed in the first part of this work which constitutes a previous paper component.
Bettencourt
M J
MJ
Laboratório Moniz de Bettencourt, Instituto de Fisiologia, Faculdade de Medicina de Lisboa.
D001775:Blood Circulation / Q000502:physiology*; D006332:Cardiomegaly / Q000503:physiopathology; D003971:Diastole / Q000502:physiology*; D004548:Elasticity; D006321:Heart / Q000502:physiology*; D006801:Humans; D016276:Ventricular Function; D014783:Viscosity
Elasticidade e viscoelasticidade no aparelho circulatório. IV. Replecção diastólica do ventrículo esquerdo.