Avtor/Urednik		Kirn, Borut
Naslov		Spreminjanje oblike delujočega levega prekata budre v začetni fazi kontrakcije
Tip		monografija
Kraj izdaje		Ljubljana
Založnik		Univerza v Ljubljani, Medicinska fakulteta
Leto izdaje		2004
Obseg		str. 60
Jezik		slo
Abstrakt		Mechanical activation of the normal left ventricle (LV) is not simultaneous. In addition, neither its spreading pattern in the axial direction nor potential consequences on the ejection function are known. To reveal them, the contraction of the LV free wall was studied. Seven guinea pig hearts in situ were studied via thoracotomy. In each heart, the ventricular and the aortic pressure were measured by two micro-tipped manometers (2Fr, Millar). Ventricular contraction was monitored with a video system (camera: Dalsa D6-02S6; framegraber: EPIX PIXCI D32; acquisition rate = 500 frames/s) and epicardial markers that served to divide the region into 20-25 triangular areas, which sizes were normalized. Linear regressions, which were using time (tk) to reach a given normalized size of triangular areas as the dependent variable and the normalized latitude (Ly) of the triangular areas as the independent variable, were performed at eachstage of the contraction. We found that the slope of the linear regression is positive throughout the contraction, meaning that regins further awaz from the apex reached given stage of the contraction later. The slope and the regression coefficient for 80 % contraction were 0,25±0,09 and 0,41±0,08 respectively. Improvements in video technique enabled us to reveal the spreading pattern of the contraction in axial direction. The contraction in the guinea pig's LV free wall occurs as a continuous contraction wave resembling a fast peristaltic wave from the apex towards the base.
Deskriptorji		MYOCARDIAL CONTRACTION THORACOTOMY HEART VENTRICLE AORTA VIDEO RECORDING GUINEA PIGS BLOOD PRESSURE ELECTROCARDIOGRAPHY IMAGE PROCESSING, COMPUTER-ASSISTED