Author/Editor		Južnič, G; Južnič, SCJE; Knap, B; Li, JK-J; Drzewiecki, G; Noordergraaf, A
Title		The endocardial surface of the left ventricle and its cylindricality
Type		članek
Source		J Cardiovasc Diagn P
Vol. and No.		Letnik 13, št. 1
Publication year		1996
Volume		str. 41-6
Language		eng
Abstract		It is well recognized that the spherical shape of the left ventricle (LV) is more economical than the cylindrical from the point of view of energy expenditure. The mechanism of valve movement, however, present this problem in another light: not a fixed shape, but a clear pattern is necessary to achieve the most economic action. An index called cylindricality is proposoed to characterize the cylindrical shape and distinguish it from a spherical form: it is defined as the alternating of the spherical and cylindrical shape of the LV during the heart cycle. Simpson's rule and the formulas for a cut-off cone were used to determine the endocardial surface and dylindricality of the LV from the echocardiogram. The observations made during the measurements described show that the cylindricality is a sensitive method to illustrate the shape changes of the LV directly after physical effort. It further shows that the mechanism of movement of the plane of the valves has an important role in the economics of the pump function of the heart.
Descriptors		EXERTION ELECTROCARDIOGRAPHY ECHOCARDIOGRAPHY HEART VENTRICLE ENDOCARDIUM ADULT RUNNING HEART RATE DIASTOLE SYSTOLE MODELS, THEORETICAL BODY SURFACE AREA