Abstract: A pacemaker for automatically confirming the presence of, and terminating, pacemaker mediated tachycardia (PMT). A number of V-pace to A-sense intervals are measured. If the measured intervals are consistent, it is possible that there is retrograde conduction giving rise to PMT. To confirm that the A-senses were not due to noise, atrial premature beats, etc., several ventricular pacing pulses are generated in a manner that eliminates the possibility of atrial beats being due to retrograde conduction; a series of simultaneous atrial and ventricular pacing pulses are generated. If A-senses consistent with the previously measured intervals are not sensed, retrograde conduction is confirmed. The PMT should have been terminated by the simultaneous atrial and ventricular pacing, but in any event the PVARP may be lengthened to exceed the longest measured V-pace to A-sense interval.

Abstract: A method for automatically determining the existence of retrograde conduction in a pacemaker patient. At a selected ventricular pacing rate, A-senses are detected, and V-pace to A-sense intervals are measured. If the measured intervals are consistent, it is possible that there is retrograde conduction. To confirm that the A-senses were not due to noise, atrial premature beats, etc., subsequent ventricular pacing pulses are generated in a manner that eliminates the possibility of atrial beats being due to retrograde conduction; a series of simultaneous atrial and ventricular pacing pulses are generated. If A-senses consistent with the previously measured intervals are not sensed, retrograde conduction is confirmed.

Abstract: An apparatus and method is described for inserting pins in holes wherein either the pin or the hole is chamfered or beveled. One part is vibrated with respect to the other in a plane orthogonal to the direction of insertion. One part is incrementally moved in the direction of insertion. When interference caused by the contact is sensed, the magnitude of the interference is determined and used to reposition the center-line of the one part in the orthogonal plane until the pin is fully inserted.