A system for delivery of a prosthetic heart valve to a beating heart, comprising; a delivery catheter having a catheter tube and a distal balloon of sufficient diameter to expand a crimped heart valve thereon, the delivery catheter also having a proximal control handle with a plurality of concentric tubes extending from within the control handle including the catheter tube , the proximal control handle having mounted on an exterior thereof both a deflection actuator for deflecting a deflectable portion of the catheter tube via a deflection pull wire and an actuator for moving one of the concentric tubes axially relative to the other concentric tubes, the deflection actuator and actuator being located so as to enable one handed operation of both; an introducer that receives the delivery catheter therethrough and has an elongated tubular sheath extending distally from a proximal housing containing a plurality of introducer valves for fluidly sealing around devices passed therethrough, the introducer having a length sufficient to extend from outside a patient through an intercostal incision and into the left ventricle of the patient; and a tubular loader defining a throughbore that receives a distal portion of the delivery catheter , and includes a structure for engaging a mating structure on a proximal end of the introducer housing and a distal nose that extends through and opens the introducer valves and facilitates passage therethrough of the delivery catheter , the loader having a proximal housing with a loader seal for fluidly sealing around the delivery catheter , and a singlehanded vent for aspirating air from within the loader housing. a delivery catheter having a catheter tube and a distal balloon of sufficient diameter to expand a crimped heart valve thereon, the delivery catheter also having a proximal control handle with a plurality of concentric tubes extending from within the control handle including the catheter tube , the proximal control handle having mounted on an exterior thereof both a deflection actuator for deflecting a deflectable portion of the catheter tube via a deflection pull wire and an actuator for moving one of the concentric tubes axially relative to the other concentric tubes, the deflection actuator and actuator being located so as to enable one handed operation of both; an introducer that receives the delivery catheter therethrough and has an elongated tubular sheath extending distally from a proximal housing containing a plurality of introducer valves for fluidly sealing around devices passed therethrough, the introducer having a length sufficient to extend from outside a patient through an intercostal incision and into the left ventricle of the patient; and a tubular loader defining a throughbore that receives a distal portion of the delivery catheter , and includes a structure for engaging a mating structure on a proximal end of the introducer housing and a distal nose that extends through and opens the introducer valves and facilitates passage therethrough of the delivery catheter , the loader having a proximal housing with a loader seal for fluidly sealing around the delivery catheter , and a singlehanded vent for aspirating air from within the loader housing. <EOS>