Faculty Collaboration Database

Segment stroke work and metabolism depend on coronary blood flow in the pig. Am J Physiol 1978 May;234(5):H597-607

Date

05/01/1978

Pubmed ID

645926

DOI

10.1152/ajpheart.1978.234.5.H597

Scopus ID

2-s2.0-0018219369 (requires institutional sign-in at Scopus site)   37 Citations

Abstract

We determined the mechanical and metabolic effects of graded myocardial ischemia in 23 open-chest, anesthetized pigs. By connecting the midportion of the left anterior descending artery (LAD) to the carotid artery via a constant volume, calibrated pump, we reduced the flow in the LAD to 0, 25, 50, and 75% of control rates for periods of 1 h. Flows of 100% and 150% were also examined. Using pairs of ultrasonic crystals to measure segment dimensions, we calculated segment shortening and thickening, and total and systolic stroke work in the ischemic and normally perfused segments. Blood gases, pH, and lactate and inosine balances were determined from the regional coronary venous blood. At coronary blood flows of 0, 25, 50, and 75% of normal resting flow, total segment work was 8 +/- 8, 25 +/- 4, 51 +/- 5, and 80 +/- 6% of control, respectively, while systolic segment work was -2 +/- 5, -10 +/- 5, 40 +/- 5, and 86 +/- 7% of control, respectively (means +/- SE). Thus, the decrease in total segment stroke work is proportional to the decrease in flow over the range 0-100%. However, no useful work (i.e., systolic work) is done until flow exceeds 25%. Segment shortening and thickening are significantly depressed with flows diminished by only 25%. Segmental inosine production correlates with lactate production and parallels decreased mechanical performance.

Author List

Stowe DF, Mathey DG, Moores WY, Glantz SA, Townsend RM, Kabra P, Chatterjee K, Parmley WW, Tyberg JV

MESH terms used to index this publication - Major topics in bold

Animals
Arteries
Coronary Disease
Coronary Vessels
Female
Hemodynamics
Male
Myocardial Contraction
Myocardium
Swine
Time Factors