June 1, 1992Circulation Research
Recruitment of an inotropic reserve in moderately ischemic myocardium at the expense of metabolic recovery. A model of short-term hibernation.
Key result
Infusion of dobutamine during moderate ischemia significantly increased the work index but worsened metabolic markers of ischemia, without causing necrosis.
Why the study?
Does dobutamine infusion recruit inotropic reserve at the expense of metabolic recovery in a swine model of moderate myocardial ischemia?
Population
40 enflurane-anesthetized swine subjected to prolonged moderate ischemia
Comparison
Dobutamine infused for 5 minutes into the… vs Control conditions
Design
Preclinical
Follow-up
Up to 85 minutes of ischemia and 2 hours of reperfusion
Authors
Discussion
Loading...
Member takes
Implication
Dobutamine may impair metabolic recovery despite recruiting reserve in moderate ischemia; leaves open translation to clinical hibernating myocardium.
Key Points
- This research aims to explore the effects of inotropic stimulation on ischemic myocardium and its metabolic recovery.
- 35 swine were anesthetized and subjected to controlled moderate ischemia by perfusing the left anterior descending coronary artery.
- Dobutamine was infused into the ischemic region after set periods of ischemia to assess functional and metabolic changes.
- Biopsies were taken to measure ATP, creatine phosphate, and lactate levels throughout the experiment.
- After 5 minutes of ischemia, creatine phosphate levels decreased significantly to 6.43 mumol/g wet weight (p<0.05).
- Dobutamine infusion significantly increased the work index at all time points without changing regional myocardial blood flow, indicating enhanced contractility.
- No evidence of tissue necrosis was observed after 85 minutes of ischemia followed by reperfusion.
Structured PICO
Does dobutamine infusion recruit inotropic reserve at the expense of metabolic recovery in a swine model of moderate myocardial ischemia?
P
Population
40 enflurane-anesthetized swine subjected to prolonged moderate ischemia (LAD cannulated and perfused at constant flow to reduce regional contractile function by approximately 50%)
I
Intervention
Dobutamine infused for 5 minutes into the ischemic region after 5, 25, 40, or 85 minutes of moderate ischemia
C
Comparator
Control conditions (moderate ischemia without dobutamine)
O
Outcome
Regional contractile function (work index) and metabolic markers (ATP, creatine phosphate, glycogen, lactate)surrogate
In a swine model of short-term hibernation, inotropic stimulation with dobutamine recruits contractile reserve but worsens metabolic markers of ischemia without causing necrosis.
Cite This Study
Schulz et al. (1992) studied Moderate myocardial ischemia (n=40). Dobutamine vs. Ischemia without dobutamine was evaluated on Regional contractile function (work index) and metabolic markers. Infusion of dobutamine during moderate ischemia significantly increased the work index but worsened metabolic markers of ischemia, without causing necrosis.