Modern adaptive dual-chamber cardiac pacemakers offer millions of combinations of noninvasively programmable operating parameters. Some pacemakers and most pacemaker programmers are microprocessor based; these "software-organized" pacemakers can undergo substantial functional redesign by noninvasive programming even after implantation. Ancillary instrumentation used in making measurements during implant and follow-up is often microcomputer based, as is experimental instrumentation used in pacing research. As electrical control of cardiac dysrhythmias becomes more sophisticated, microcomputer applications in many aspects of pacing are proliferating in research, manufacturing, and clinical practice.

Computers↗

PubMedDate not supplied

Autogenous vein graft thrombosis following exposure to calcium-free solutions (calcium paradox).

The morphological and functional effects of calcium-free and calcium-containing solutions on canine jugular vein intima were examined under conditions which closely resemble those techniques currently employed in peripheral vascular and aortocoronary bypass surgery. Veins that had been exposed only to calcium-containing solutions remained patent for the duration of the experimental period. Vein perfusion with a calcium-free solution, however, resulted in disruption of the jugular vein intima once calcium ions were reintroduced. Autogenous as a femoral arterial graft became thrombosed within 60 minutes. It is therefore suggested that vein grafts of autogenous origin be irrigated with calcium-containing solutions to prevent intimal damage and thrombosis.

Animals↗

PubMedDate not supplied

Optimum filters for pacemakers sensing amplifiers.

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Electronics, Medical↗