J. Naito et al., INFLUENCE OF PRELOAD, AFTERLOAD, AND CONTRACTILITY ON MYOCARDIAL ULTRASONIC TISSUE CHARACTERIZATION WITH INTEGRATED BACKSCATTER, Ultrasound in medicine & biology, 22(3), 1996, pp. 305-312
Citations number
34
Categorie Soggetti
Radiology,Nuclear Medicine & Medical Imaging",Acoustics
Influence of hemodynamic changes in preload, afterload and contractili
ty on myocardial integrated backscatter (IB) was studied in 26 adult m
ongrel dogs by measuring myocardial IB calibrated with the backscatter
from the blood during volume infusion (preload alteration), during ao
rtic constriction (afterload alteration), and during dobutamine or pro
pranolol infusion (contractility alteration). Changes in preload, afte
rload or contractility did not significantly affect the calibrated myo
cardial IB either in the septum or in the posterior wall. Changes in p
reload and afterload did not affect the magnitude of cyclic variation
in IB. However, dobutamine produced a significant increase in the magn
itude of cyclic variation in IB and propranolol significantly decrease
d the magnitude of cyclic variation in IB. These data indicated that t
he calibrated myocardial IB is independent of preload, afterload and c
ontractility, and that the magnitude of cyclic variation in IB is infl
uenced by contractility. We may estimate static (related to histologic
al changes such as fibrosis, edema, necrosis, and so on) and dynamic (
related to myocardial contraction such as sarcomere length, muscle fib
er orientation, and so on) properties of the myocardium more precisely
using myocardial IB calibrated with the backscatter from the blood in
addition to the magnitude of cyclic variation in IB.