PMID: 7317217Nov 1, 1981Paper

Systolic time intervals in measurement of inotropic response to drugs

British Heart Journal
B F JohnsonS H Taylor


During periods of tachycardia induced by atrial pacing in eight patients, moderate increments in dP/dt(max) and (dP/dt)/CPIP (common produced intraventricular pressure) and moderate reductions in left ventricular ejection time (LVET) and Q-S2 were demonstrated. These changes varied between individuals, but reduction in systolic intervals was consistently less than that reported from populations showing a range of resting heart rates. Individual regression formulae relating each variable to paced heart rate were used to calculate rate-dependent and rate-independent changes induced by isoprenaline and ouabain. Despite technical difficulty in precise measurement of systolic intervals, there was an excellent inverse correlation between rate-independent changes in Q-S2 and in both dP/dt(mac) and (dP/dt)/CPIP. Rate-independent change in Q-S2 appears to be a practical, moderately sensitive, and reasonably precise measure of the inotropic effect of a drug which does not radically alter left ventricular end-diastolic pressure or blood pressure. Day-to-day variation in systolic intervals may limit the use of the technique to studies of short duration.


Apr 7, 1977·The New England Journal of Medicine·D H Spodick
Apr 1, 1970·The American Journal of Cardiology·C C MetzgerJ J Leonard
Feb 1, 1968·Circulation·A M WEISSLERC D Schoenfeld
Apr 1, 1969·The American Journal of Cardiology·A M WEISSLERC D Schoenfeld
Apr 1, 1966·The American Journal of Cardiology·W S HarrisA M WEISSLER
Feb 1, 1967·The American Journal of Cardiology·A Benchimol, J G Ellis
Jan 1, 1962·The Journal of Clinical Investigation·W L GLEASON, E BRAUNWALD
Jun 1, 1963·Circulation Research·A G WALLACES J SARNOFF


Jan 1, 1993·European Journal of Clinical Pharmacology·Q Li, G G Belz
Jan 1, 1983·Current Medical Research and Opinion·I L NautaD P Hertzberger
Mar 1, 1989·The Journal of Surgical Research·P RmöO J Rämö
Mar 1, 1986·British Journal of Clinical Pharmacology·T HashimotoK Kondo
Mar 1, 1987·Pharmacology & Toxicology·J BondeJ P Kampmann
Jan 1, 1983·Acta Medica Scandinavica·M Kupari

Related Concepts

Cardiotonic Agents
Pulse Rate
Left Ventricular Structure
Myocardial Contraction

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