Abstract: An apparatus and method for testing prosthetic heart valves prior to implant in the human body provides a test chamber having a flow channel therethrough and a passageway which receives a mounting fixture for a heart valve. The test chamber is used in a mock circulatory loop with the flow channel being in the loop. Preferably, the test chamber has a transverse passageway that intersects the flow channel, and the mounting fixture advances completely through the test chamber from an insertion location to a disconnect location while a dynamic seal is maintained. Two such test chambers may be used in a mock loop, and the loop is configured with an intake chamber fluidly interconnecting one side of each test chamber, and a restriction chamber fluidly interconnecting the other sides of the test chambers. The restriction chamber is variable, and pressure compensation is provided between each of test chambers and the restriction chamber.