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Title: Microsphere reference flow samples during systemic flow adjustment

Journal Article · · Am. J. Physiol.; (United States)
OSTI ID:5720697

Regional myocardial blood flow measurements in the right heart bypass preparation can be particularly valuable, since this preparation provides control of the main hemodynamic determinants of coronary blood flow. The authors examined the validity of aortic reference flow samples in relation to coronary samples during continuous systemic flow adjustment for aortic pressure control in six dogs on right heart bypass, anesthetized with chloralose and urethan. Radioactively-labelled microsphere concentrations were compared in paired reference flow samples drawn from the aortic arch and from a coronary artery for 119 left atrial microsphere injections. During left subclavian artery infusion and during femoral artery infusion at rates above 2000 ml/min, there were high percentage errors in microsphere concentration between paired samples, consistent with aortic sample dilution by systemically infused blood. In 52 injections during withdrawal or femoral infusion below 2000 ml/min, at cardiac outputs of 390-4800 ml/min. Linear regression related these coronary to aortic microsphere concentrations by the equation Y = 1.005X - 1.64, r = 0.997, S/sub y-x/ = 13.2 (5.9%). These data indicate that valid aortic reference flow samples can be obtained within specific hemodynamic conditions during systemic flow adjustment in the right heart bypass preparation.

Research Organization:
Massachusetts General Hospital, Boston
OSTI ID:
5720697
Journal Information:
Am. J. Physiol.; (United States), Vol. 252:4
Country of Publication:
United States
Language:
English