Document Detail


Timing and velocity of ejection as major determinants of end-systolic pressure in isolated rabbit hearts.
MedLine Citation:
PMID:  7994854     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Systolic shortening is known to produce muscle deactivation. The present study was designed to analyze whether the velocity and the timing of ejection play a role on end-systolic pressure-volume relations (ESPVR). METHODS AND RESULTS: In isolated rabbit hearts, left ventricular pressure and volume were recorded and digitized, and left ventricular volume was controlled by a servosystem (4-millisecond cycles) to alter the timing of ejection. A significant deficit in end-systolic pressure was observed when ejection was late in systole with respect to earlier ejection. This was associated with a significantly reduced end-systolic elastance. End-systolic pressure of beats with slow ejection was intermediate between that of the beats with early ejection and that of beats with late ejection with a significantly increased end-systolic volume compared with beats with early rapid ejection. The same results were obtained with hypertrophied hearts (abdominal aortic stenosis). Pressure-volume loop areas were significantly increased in beats with slow ejections and with rapid delayed ejections versus early rapid ejections. No change in the positive peak of dP/dt was observed when the timing and the velocity of ejection were modified. CONCLUSIONS: ESPVR is modified by the ejection profile, with a decreased end-systolic pressure and an increased pressure-volume loop area related to the velocity and the amount of shortening during the end-systolic phase. These indices of ventricular function thus must be used with caution when the timing of ejection is altered, and the end-diastolic volume-peak dP/dt relation may be a better index of ventricular function.
Authors:
A Ezzaher; T el Ouazzani; B Crozatier
Related Documents :
1478204 - Ventricular pressure-volume relations in vivo.
3189174 - Influence of age on left ventricular contractility.
24572914 - Neuroadrenergic disarray in pseudo-resistant and resistant hypertension.
622954 - Post-extrasystolic potentiation of ischemic myocardium by atrial stimulation.
12402264 - Vitamin a in the cerebrospinal fluid of patients with and without idiopathic intracrani...
16573454 - Hypertension in the critically ill patient.
Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Circulation     Volume:  90     ISSN:  0009-7322     ISO Abbreviation:  Circulation     Publication Date:  1994 Dec 
Date Detail:
Created Date:  1995-01-17     Completed Date:  1995-01-17     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0147763     Medline TA:  Circulation     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  3055-62     Citation Subset:  AIM; IM    
Affiliation:
Unité INSERM U400, Faculté de Médecine, Créteil, France.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure*
Blood Volume
Cardiomegaly / physiopathology
Heart / physiology*
Myocardial Contraction
Rabbits
Reference Values
Systole
Time Factors
Ventricular Function, Left*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Effect of exercise on left ventricular mechanical efficiency in conscious dogs.
Next Document:  Effect of ventilation on resuscitation in an animal model of cardiac arrest.