Ventricular performance and myocardial water content during hemodilution in dogs

Abstract

In dogs anesthetized with chloralose-urethan on right heart bypass, left ventricular (LV) performance was assessed at constant LV stroke work before and for up to 2.5 h after crystalloid hemodilution was established. Lowering the hematocrit from 43.3 +/- 1.3% to 13.6 +/- 1.7% (SE) did not significantly change LV end-diastolic pressure (LVEDP) initially. After 80 min LVEDP increased slightly by 1.7 +/- 0.6 cmH2O (P less than 0.05) at a stroke work of 17.3 +/- 2.3 g.m. The value of dP/dt did not change significantly throughout. When LV function curves were generated by increasing cardiac output, the stroke work attained at an LVEDP of 10 cmH2O decreased with hemodilution from 23.9 +/- 3.5 to 20.8 +/- 3.9 g.m (NS). LV wall water content increased with hemodilution, from which it could be calculated that there was an 18.6% increase in LV mass. Thus, despite an increase in LV external girth demonstrated by LV circumferential gauges, it is possible that increased wall thickness due to the water gain resulted in little change or an actual decrease in LV end-diastolic volume. Thus, profound hemodilution can be attained with only slight depression of LV performance.

Life-Threatening Hypocalcemia After Abdominal Aortic Aneurysm Repair in Patients With Renal Insufficiency

“…Calcium binding to albumin vanes greatly between patients (from 0.2 to 1.2 mg-dL-'.g albumin-') and no reliable correction factor can be calculated for such changes in albumin levels. In experimental models, hemodilution alone (hematocrit diluted from 43% to 14% over 2 h) with lactated Ringer's solution did not result in hypocalcemia (8). Thus, the majority of experimental evidence suggests that calcium homeostatic mechanisms should maintain normal ionized calcium concentrations despite the documented operative stress.…”

Reversal of Iatrogenic Myocardial Edema and Related Abnormalities of Diastolic Properties in the Pig Left Ventricle

“…We also argue that the hematocrit value of the perfusate was not a factor, because a hematocrit value of 9% is said to minimally impair myocardial oxygen delivery. 4,5 Any myocardial ischemia and hyperemia resulting from 1 minute of perfusion at this hematocrit value should have been too short-lived to have affected the results. The degree of hemodilution was based on a prior study.…”

“…This task has been difficult and has attracted many investigators. 4,[3][4][5][6][7][8][9][10] Ideally, edema should be induced and reversed without cardiac injury. Techniques that are highly likely to cause edema, including cardiopulmonary bypass (CPB) and Langendorff perfusion, should be avoided.…”

Ventricular Function in Surgery for Congenital Heart Disease

“…Geffin et al related LV, circumference, wall thickness, MWC, and LVM [16]. Leaf demonstrated that edema caused by sodium pump dysfunction was prevented by hypertonic perfusates [17–20].…”