Results
Myocardial perfusion was significantly decreased in the HF-NAP group both at rest and during ventricular pacing. Microvessel relaxation responses to sodium nitroprusside and adenosine 5′-diphosphate were similar between groups. Tissue 11-d-TXB2 levels were similar between groups, but tissue 6-k-PGF1α was significantly decreased in the HF-NAP group (P = .001). Expression of thromboxane synthase was significantly higher in the HF-NAP group (P = .02), while prostacyclin synthase expression was significantly decreased in the HF-NAP group (P = .04). Capillary density was higher in the HF-NAP group (P = .005). Proangiogenic vascular endothelial growth factor (VEGF; P = .0002) and Akt (P = .01) were downregulated in the HF-NAP group.