ISSN:
1435-1803
Keywords:
end-systolicpressure-volume relationship
;
ventricular interaction
;
systemicvascular resistance
;
rightventricular volume
;
rightventricular shortening
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary It has been reported that left ventricular end-systolic volume decreases during arteriovenous shunt and increases during subclavian artery-left atrium shunt at a constant end-systolic pressure. The mechanism of the opposing changes in end-systolic volume during the two types of shunt is not clear. One possible cause is that left ventricular pump function with enhanced right ventricular ejection differs from that without enhancement. To investigate this hypothesis, we studied the two types of shunt (Aorto-femoral vein shunt, AoFV; aorto-left atrium shunt, AoLA) with matched reduction of systemic vascular resistance in open-chest dogs with β-blockade. Both right and left ventricular volumes and shortenings were assessed from short-axis views by two-dimensional (2D)-echocardiogram. Left ventricular end-systolic short-axis area decreased from 76 ± 3 to 62 ± 3% in AoFV shunt (p 〈 0.05), but tended to increase in AoLA shunt (76 ± 4 in control state vs 81 ± 5% in AoLA, NS) in spite of a similar reduction in left ventricular end-systolic pressure. There was no difference in left ventricular shortening, but significant differences were observed in right ventricular shortening (50 ± 8 in AoFV vs 24 ± 7% in AoLA, p 〈 0.05) and right ventricular short-axis area at end-diastole (142 ± 6 in AoFV vs 96 ± 3% in AoLA, p 〈 0.01), and at end-systole (92 ± 8 in AoFV vs 73 ± 7% in AoLA, p 〈 0.05) between the two types of shunt. We conclude that the different changes in left ventricular end-systolic short-axis area found in the two shunts are not caused by the different left ventricular shortenings, but by the different right ventricular mechanical actions. These findings suggest that left ventricular pumping action in the high output state changes, depending on whether it is accompanied by augmented ejection of the right ventricle or not.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02193872
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