Contrast enhanced computed tomography (CT) is able to assess coronary stenosis and left ventricular function. Due to first pass effect it is able to assess surrogate markers of myocardial perfusion. We assessed the hypothesis that computed tomography can detect hibernating myocardium.
Methods and results: A well-established porcine model of hibernating myocardium was used for this study. In this model of chronic coronary stenosis there is ~20% reduction in regional myocardial perfusion. Six pigs underwent instrumentation of the proximal left anterior descending (LAD) coronary artery with an external constrictor. Paired Student-T test was used to compare LAD territory and opposite myocardial segments. After 12 weeks echocardiographic studies detected regional left ventricular dysfunction by M-mode to the LAD territory (Table
). At that time EKG guided computed tomography showed severe stenosis to the LAD. Myocardial signal density (MSD) by CT was assessed in 24 opposing segments during diastole (Hounsfield Units). MSD within the territory of the LAD was significantly lower than MSD of opposing segments (Table
). Ratio of signal density (RSD) between myocardium and left ventricular cavity was significantly lower within the LAD territory in comparison to opposing segments (Table
).
Conclusion: In a well-established porcine model of hibernating myocardium contrast enhanced computed tomography was able to detect areas of decreased attenuation suggesting that CT might be able to detect hibernating myocardium.
Table
Contrast echocardiographic evaluation of regional myocardial perfusion in a porcine model of hibernating myocardium
