Biomedical subjects

C J Del Marco

Publications and source records attributed to C J Del Marco.

2 recordsLinked to original sources

PubMed1982

A new symbolic language for diagramming pacemaker/heart interaction.

A new symbolic language is presented that can be used to diagram pacemaker/heart interactions. The language symbolically indicates "normally" conducted and ectopic events; pacemaker stimuli; pacemaker capture of the chamber; triggered pacemaker stimuli by "normal" or ectopic events; as well as such anomalous pacemaker/heart interactions as failure to sense; "crosstalk" between electrodes; and "normal," ectopic, or paced events in one chamber sensed by the electrode in the other chamber. In addition, symbols are provided to represent antegrade and retrograde accessory pathway conduction, and electronic and physiological refractory intervals. A common baseline is used to separate symbols for atrial activity, above the baseline, from those for ventricular activity, below the baseline. Parallel baselines are used to plot refractory intervals. Thus, even complex dual-chamber pacemaker operating modes can be represented with intrinsic and stimulated cardiac response to pacemaker operation. The language can be sketched out informally for description of general concepts or drafted on millimeter grid paper to make precise timing notations. It is especially useful for interdisciplinary communication of ideas about complex pacemaker/heart interactions.

Atrial Function↗

PubMed1981

A new code for pacemaker operating modes.

A new code is proposed that can be used as a supplement to th ICHD code to describe single- and dual-chamber pacemaker operating modes. The code visually indicates the chamber(s) involved by means of a common base-line with indicators for atrial activity above and ventricular activity below. Letter indicators are used. For single-chamber units, an O represents the chamber in which no pacemaker activity occurs. P represents pacing, S sensing, IA inhibition by a sensed atrial event, IV inhibition by a sensed ventricular event, TA triggering by a sensed atrial event, and TV triggering by a sensed ventricular event. For example, a pacemaker mode described as PSIAIV/PSTAIV paces and senses both chambers; inhibits atrial pacing by a sensed event in either chamber; inhibits ventricular pacing by a sensed ventricular event but triggers ventricular pacing, after an assumed A-V delay, by a sensed atrial event. Thus even the most complex modes of pacing operation can be clearly and accurately described by means of this new code. Especially useful in teaching applications is the distinction of activity by chamber and the description of response in one chamber to activity in the other.

Heart↗