In Reply:-Thank you for giving Datascope the opportunity to respond to this exchange of correspondence regarding transesophageal atrial pacing as a trigger for intraaortic balloon pumps (IABP).
The result of proper triggering and timing is the synchronization of intraaortic balloon (IAB) inflation and deflation action with left ventricular contraction. When available, the R-wave is the preferred method of IABP triggering. However, Datascope pumps provide the ability to alternatively trigger from ventricular pacing pulses as precursors to ventricular stimulation and contraction.
No Datascope IABP has ever been designed to trigger off the atrial pacing pulse, due to vagaries of A-V pacing intervals and the potential dissociation of atrioventricular activity. Our newest pump consoles (System 95 and 97) provide a “Pacer A” mode. This mode is only invoked to reject large atrial pacing artifact that may compete with depressed QRS complexes during R-wave triggering (i.e., after cardioplegia). Triggering on an atrial pacing stimulus will result in both early inflation and early deflation of the IAB. The longer the atrioventricular pacing delay, the earlier the timing will occur.
Debra L. Joseph, Vice President, Clinical Services, Datascope Corporation, 15 Law Drive, Fairfield, New Jersey 07004.
(Accepted for publication October 18, 1996.)
