The effect of human amniotic fluid on the isolated perfused rat heart.

To test the hypothesis that amniotic fluid directly affects cardiac function, isolated rat hearts were perfused with varying concentrations of centrifuged and filtered human amniotic fluid. The most consistent change seen was a dose-dependent decrease in coronary flow rate. With 10% concentrations, a wide spectrum of changes was seen in both a positive and a negative direction for left ventricular pressure and change in pressure with respect to time, which were closely correlated with the degree of decrease in coronary flow rate. If amniotic fluid has a direct role in depressing cardiac function in amniotic fluid embolism, it may act by decreasing coronary flow rather than by directly suppressing myocardial activity.