February 1, 1987Cardiovascular Research
Absence of coronary vascular reserve in myocardium distal to a fixed coronary stenosis
Why the study?
Does intracoronary adenosine increase coronary flow in myocardium distal to a fixed coronary stenosis in a canine model?
Population
14 dogs (6 in first experiment with moderate stenosis, 8 in second experiment with severe stenosis)
Comparison
Intracoronary adenosine infusion during fixed… vs Resting state with fixed coronary stenosis…
Design
Preclinical
Authors
Discussion
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Implication
Alerts to possible subendocardial steal with adenosine in stenosed vessels; leaves open relevance to human coronary disease.
Key Points
- The study aims to determine if vascular reserve is depleted in regions with resting blood flow deficits due to coronary stenosis.
- Left anterior descending or circumflex artery cannulation for reactive hyperaemia assessment in dogs.
- Moderate and severe stenosis produced in coronary arteries with effects on coronary blood flow measured during adenosine infusion.
- Isolated coronary veins used for segment length analysis in ischaemic and non-ischaemic zones.
- Resting coronary flow decreased from 41(3) to 29(6) ml.min-1 with stenosis (p<0.05).
- Adenosine infusion increased flow from 29(6) to 34(7) ml.min-1 (p<0.05) and to 50(10) ml.min-1 with stenosis adjustment (p<0.05).
- Subendocardial flow decreased with adenosine (0.89(0.26) to 0.78(0.23) ml.g-1.min-1, p<0.05) but increased with pressure adjustments.
Structured PICO
Does intracoronary adenosine increase coronary flow in myocardium distal to a fixed coronary stenosis in a canine model?
P
Population
14 dogs (6 in first experiment with moderate stenosis, 8 in second experiment with severe stenosis)
I
Intervention
Intracoronary adenosine infusion (6 mumol.min-1) during fixed coronary stenosis
C
Comparator
Resting state with fixed coronary stenosis before adenosine infusion
O
Outcome
Coronary blood flow and regional myocardial blood flow (subendocardial and subepicardial)surrogate
In a canine model of fixed coronary stenosis, adenosine administration increases total coronary flow but paradoxically decreases subendocardial flow, indicating exhausted vascular reserve and potential coronary steal.
Cite This Study
Klein et al. (1987) studied this question.