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Myocardial Stimulation with Ultrashort Duration Current Pulses
Author(s) -
PEARCE J.A.,
BOURLAND J.D.,
NEILSEN W.,
GEDDES L.A.,
VOELZ M.
Publication year - 1982
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1982.tb02191.x
Subject(s) - time constant , duration (music) , medicine , pulse duration , stimulus (psychology) , stimulation , capacitance , millisecond , mechanics , biomedical engineering , physics , electrode , optics , electrical engineering , acoustics , psychology , laser , quantum mechanics , astronomy , psychotherapist , engineering
In order to identify a practical short‐duration limit for stimulating myocardium, theoretical and experimental studies were carried out using dog and turtle hearts The strength‐duration curves for current, charge and energy were derived from the standard excitable membrane model which employs a parallel resistance and capacitance. From these derivations, the predicted duration for minimum energy was identified. The experimentally measured strength‐duration curves for two types of myocardium followed the predicted vaiues cioseiy The duration for minimum energy was calculated to be 1.25 times the membrane time constant. The practical short‐duration limit for a pacemaking stimulus is about 30% of the membrane time constant. For dog myocardium the average time constant was 2.4 ms Therefore, a practical stimulus duration for minimum charge in the dog should be no longer than about two‐tenths of a millisecond, although shorter duration stimuli are equally effective This minimum charge criterion provides the minimum drain on the stimulator power supply