[Stress-ultrasound study of hemodynamic reserve of aortic compression chamber in atherosclerosis: effect on coronary blood flow].
OBJECTIVE
To study the role of hemodynamic reserve of aortic compression chamber (ACC) in compensation of coronary blood flow during stress.


METHODS
Ninety three subjects (78 men and 15 women) including 74 patients with chronic ischemic heart disease (mean age 50-/+7 years) and 19 healthy volunteers (mean age 45-/+5 years).


METHODS
Hemodynamic reserve of ACC was defined as volume of blood deposited in walls of ascending aorta at the end of systole. M-mode cross-section of ascending aorta was obtained during transesophageal pacing with long-axis view from parasternal approach. Antegrade and retrograde blood flow in the ascending aorta was registered through suprasternal approach with wave-impulse doppler. Movements of left ventricular walls were assessed via apical approach with the use of 12-segment model. The following factors were directly determined or calculated: morphometrical parameters, elasticity and rigidity of aorta, temporal and amplitudal characteristics of antegrade and retrograde flow in ascending aorta, stroke volume, cardiac output, coronary fraction of stroke volume, coronary blood flow. Results. During transesophageal pacing in healthy subjects elastic ACC despite increasing limit of diastole duration accumulated energy, pressure and part of volume of moving blood, providing sufficient flow in the coronary circulation. In patients with ischemic heart disease rigid ACC functioned as hydrodynamically inert tube being the cause of progressive diminishment of coronary flow.


CONCLUSIONS
Decreased capacitance and functional reserves of ACC in atherosclerosis constituted the first hemodynamic barrier determining deficit of coronary blood flow during stress.
Vrublevskiĭ
A V
AV
Boshchenko
A A
AA
Karpov
R S
RS
D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D003331:Coronary Vessels / Q000503:physiopathology*; D004452:Echocardiography; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged