Abstract 11313: Evidence for Different Brain Processing from the Left and the Right Ventricles by Brain Functional MRI in Rats
Background: Patients with anterior and those with inferior myocardial infarction often present different clinical manifestation. Indeed, anatomical studies have demonstrated different neuronal innervations between the left (LV) and the right ventricles (RV), suggesting functional differences in the brain processing between the 2 ventricles. In this study, we thus examined the possible difference in the brain processing from the LV and the RV by brain functional MRI (fMRI) in rats.
Methods: Male Wister rats were inserted an electrical stimulation catheter into the LV (n=8) or the RV (n=6). fMRIs were recorded during continuous LV or RV pacing for 10 blocks with 2 mA for 30 sec followed by that with 0.2 mA for 60 sec. Changes of the ventricular stimulation intensity from 0.2 mA to 2 mA did not cause significant blood pressure change that could contaminate fMRI signals. fMRI signal changes induced by the increase in electrical stimulation intensity were analyzed by statistical parametric mapping at significant threshold of P<0.001 (uncorrected).
Results: LV stimulation showed significant fMRI signals in the somatosensory cortex, hippocampus, motor cortex, caudate putamen, cingulate cortex and brainstem, whereas RV stimulation activated the somatosensory cortex, hippocampus and insula. When comparing the LV and the RV stimulation, greater brain activation was noted in different portions of the hippocampus (Figure).
Conclusions: To the best of our knowledge, this is the first study demonstrating the difference in the brain activation during stimulation of the different portion of the heart. The brain regions identified in this study can contribute to the different clinical manifestations between anterior and inferior myocardial infarction.
- © 2011 by American Heart Association, Inc.