Page 121 - Assessing right ventricular function and the pulmonary circulation in pulmonary hypertension Onno Anthonius Spruijt

be reversed by epoprostenol therapy [74]. Although the mechanisms responsible for this metabolic switch remain to be elucidated, one possibility is that RV ischemia might induce such changes. Gomez et al. showed by using stress myocardial scintigraphy that nine of the 23 PAH patients examined had images consistent with RV ischemia [75]. In addition, they found a significant correlation between RV ischemia obtained through myocardial perfusion scintigraphy and hemodynamic measures of RV failure, underpinning the possible contribution of ischaemia to RV failure.
[11C]-Acetate and [15O]-oxygen tracers allow to study the oxidative metabolism of the pressure overloaded RV. In a study by Wong et al. it was shown by means of [11C]-acetate PET that heart rate and systolic pulmonary artery pressure are the main determinants of oxygen consumption in PAH patients [76]. In addition these tracers allow to obtain more insight in the pathophysiology of the
Chapter 7
Figure 6: upper image: glucose consumption in the right and left ventricle as indicated as
MRglu (metabolic rate
(μmol/ml/min) measured by
Lower image: corresponding short axis view measured by MRI
of glucose 18FDG-PET.
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