Key result
In a porcine model, dobutamine stress echocardiography identified 41 of 55 abnormal myocardial segments as acute hibernating myocardium, with ΔAPV correlating with the amount of hibernating segments.
Why the study?
Does dobutamine stress echocardiography combined with intracoronary Doppler guidewire evaluation characterize coronary hemodynamics in a porcine model of acute hibernating myocardium?
Does dobutamine stress echocardiography combined with intracoronary Doppler guidewire evaluation characterize coronary hemodynamics in a porcine model of acute hibernating myocardium?
In a porcine model of acute hibernating myocardium, the change in average peak velocity during dobutamine stress correlates with the number of hibernating segments, suggesting a mechanism for DSE detection of AHM.
Answers are grounded in this paper and cite their sources.
Hypothesis-generating in porcine AHM; leaves open human validation of DSE-Doppler hemodynamics.
PURPOSE: To determine the coronary hemodynamic characteristics of acute hibernating myocardium (AHM), evaluate the changes in coronary hemodynamics during dobutamine infusion, and investigate the mechanisms by which dobutamine stress echocardiography (DSE) detects AHM. METHODS: The porcine model of acute hibernating myocardium was created in 10 animals, all of which underwent DSE with doses of 0-40 μg/kg/min. Myocardial segments abnormality was used as a DSE criterion for evaluating AHM. An intracoronary Doppler guidewire was used to measure the coronary hemodynamics; electrocardiography and systemic hemodynamics were recorded simultaneously. The ischemic regions of myocardium were reperfused, and all variables were recorded. Finally, the animals were euthanized and pathologic changes in the heart tissue were documented. RESULTS: There was no myocardium necrosis. There were 55 myocardial segments with abnormal DSE responses after stenosis, among which 41 segments were judged as AHM because of a biphasic response. Average peak velocity (APV) and coronary flow velocity reserve were improved during DSE. Coronary and systemic hemodynamics were increased during dobutamine infusion. There were significant differences for APV at all evaluated doses and for heart rate blood pressure product at higher doses. The difference between APV resting values and the values for peak dosage (ΔAPV) correlated with the amount of AHM during DSE. Coronary volume blood flow and coronary flow velocity reserve decreased after stenosis. CONCLUSIONS: ΔAPV may reflect the number of hibernating segments. The relative imbalance between blood supply and oxygen consumption in regional myocardium may be one of the mechanisms by which DSE detects AHM.
No takes yet. Share an insight, caveat, or question.
Li et al. (2011) studied Acute hibernating myocardium (n=10). Dobutamine stress echocardiography and intracoronary Doppler guidewire was evaluated on Coronary hemodynamics including average peak velocity (APV). In a porcine model, dobutamine stress echocardiography identified 41 of 55 abnormal myocardial segments as acute hibernating myocardium, with ΔAPV correlating with the amount of hibernating segments.
Synapse has enriched 10 related papers. Consider them for comparative context: