The coordination of long chain fatty acid (LCFA) transport across the mitochondrial membrane (V_PAL) with subsequent oxidation rate through β-oxidation and the tricarboxylic acid (TCA) cycle (V_tca) has been difficult to characterize in the intact heart. Kinetic analysis of dynamic ¹³C-NMR distinguished these flux rates in isolated rabbit hearts. Hearts were perfused in a 9.4 T magnet with either 0.5mM [2,4,6,8,10,12,14,16-¹³C₈] palmitate (n=4), or 0.5mM ¹³C-labeled palmitate plus 0.08mM unlabeled butyrate (n=4). Butyrate is a short chain fatty acid (SCFA) that bypasses the LCFA transporters of mitochondria. In hearts oxidizing palmitate alone, the ratio of V_TCA to V_PAL was 8:1. This is consistent with one molecule of palmitate yielding eight molecules of acetyl-CoA for the subsequent oxidation through the TCA cycle. Addition of butyrate elevated this ratio; V_TCA/V_PAL=12:1 due to an SCFA-induced increase in V_TCA of 43% (p<0.05). However, SCFA oxidation did not significantly reduce palmitate transport into the mitochondria: V_PAL=1.0±0.2μmol/min/g dw with palmitate alone versus 0.9±0.1 with palmitate plus butyrate. Thus, the products of β-oxidation are preferentially channeled to the TCA cycle, away from mitochondrial efflux via carnitine acetyltransferase.