Document Detail


End-systolic pressure-diameter relationships during pulsus alternans in intact pig hearts.
MedLine Citation:
PMID:  3963216     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Pulsus alternans has previously been ascribed to variations in end-diastolic fiber length and/or an alternating contractile state. In six paced, whole blood-perfused, intact, working pig hearts, left ventricular internal diameters were measured with ultrasonic crystals, and left ventricular pressures were measured with a micromanometer-tipped catheter. Pulsus alternans was induced with propranolol (24-51 micrograms X kg-1 X min-1). End-systolic pressure-diameter relationships were determined during pulsus alternans from a series of consecutive, variably volume-loaded beats using a previously described technique. Beats analyzed prior to any change in loading conditions revealed a left ventricular pressure of 62.7 +/- 8.7 mmHg for the strong beats and 55.2 +/- 7.0 for the weak beats (P less than 0.050). The end-diastolic diameter prior to the stronger beats was larger than that prior to the weaker beats (24.80 +/- 2.73 vs. 23.82 +/- 2.82 mm, P less than 0.025), but there was no significant difference in the corresponding end-diastolic pressures. The maximum dP/dt of the strong beats was 1,275 +/- 249 mmHg/s compared with 1,038 +/- 222 for the weak beats (P less than 0.025). The slope of the end-systolic pressure-diameter relationship, which provides an index of contractility independent of end-diastolic diameter, averaged 42.3 +/- 6.4 mmHg/mm for the strong beats and 24.4 +/- 6.8 for the weak beats (P less than 0.025). These data support an alternating contractile state as an independent mechanism for pulsus alternans in the intact animal.
Authors:
W P Miller; A J Liedtke; S H Nellis
Related Documents :
10564146 - Age-related left ventricular function in the mouse: analysis based on in vivo pressure-...
2447416 - Beneficial effects of nicorandil on cardiovascular hemodynamics and left ventricular fu...
3731426 - Effect of amrinone on right ventricular function: predominance of afterload reduction.
1419446 - Effect of graded infusion rates of propofol on regional and global left ventricular fun...
8810826 - Bone lead as a risk factor for hypertension in men.
741206 - Raynaud phenomena and finger systolic pressure during cooling.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The American journal of physiology     Volume:  250     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1986 Apr 
Date Detail:
Created Date:  1986-05-13     Completed Date:  1986-05-13     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H606-11     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure
Elasticity
Female
Heart / physiology*
Heart Ventricles / anatomy & histology
Hemodynamics
Male
Myocardial Contraction*
Stroke Volume
Systole
Grant Support
ID/Acronym/Agency:
HL-21209-05/HL/NHLBI NIH HHS

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


Previous Document:  Adenosine deaminase attenuates canine coronary vasodilation during systemic hypoxia.
Next Document:  Contractile responses to ouabain and K+-free solution in aorta from hypertensive rats.