Delayed recovery of fatty acid metabolism after transient myocardial ischemia: A potential imaging target for “ischemic memory”
- 52 Downloads
The myocardium preferentially oxidizes free fatty acids for energy production. However, the dependency of this metabolic pathway on oxygen makes this process vulnerable to ischemia. The energy requirements of the myocardium are subsequently met by the oxidation of carbohydrates, particularly glucose. Recovery of fatty acid metabolism lags behind restoration of perfusion, resulting in the phenomenon ofmetabolic stunning. This decrease of fatty acid utilization following ischemia can be imaged with fatty acid radiotracers, particularly β-Methyl-p-123I-iodophenyl pentadecanoic acid (BMIPP), which demonstrates markedly limited metabolism via β-oxidation, resulting in prolonged retention in the cardiomyocyte. Thus, in patients presenting with chest pain and no prior myocardial infarction, abnormal BMIPP uptake at rest reflects metabolic alteration caused by the preceding ischemia, also termedischemic memory.
KeywordsSingle Photon Emission Compute Tomography Myocardial Perfusion Fatty Acid Metabolism Fatty Acid Uptake Myocardial Perfusion Single Photon Emission Compute Tomography
Unable to display preview. Download preview PDF.
References and Recommended Reading
- 1.Of importance Dilsizian V, Bateman TM, Bergmann SR, et al.:Metabolic imaging with beta-methyl-p-[(123)I]-iodophenyl-pentadecanoic acid identifies ischemic memory after demand ischemia.Circulation 2005,112:2169–2174. This prospective study investigated the uptake of BMIPP in patients undergoing clinically indicated exercise201Tl myocardial perfusion studies. BMIPP metabolic defects at rest were observed up to 30 hours in greater than 90% of the patients after an ischemic episode on the treadmill. There was also good correlation between the extent and severity of the stress thallium defect and rest BMIPP defect when summed segmental scores were applied.PubMedCrossRefGoogle Scholar
- 16.Dormehl IC, Hugo N, Rossouw D, et al.:Plamar myocardial imaging in the baboon model with iodine-123-15-(iodoph enyl)pentadecanoic acid (IPPA) and iodine-123-15-(P-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP), using time-activity curves for evaluation of metabolism.Nucl Med Biol 1995,22:837–847.PubMedCrossRefGoogle Scholar
- 20.Of importance Higuchi T, Taki J, Nakajima K, et al.:Time course of discordant BMIPP and thallium uptake after ischemia and reperfusion in a rat model.J Nucl Med 2005,46:172–175. This demonstrated the time-dependent changes in the uptake of BMIPP in a rat myocardial ischemia model. This article elucidated the early increase of BMIPP uptake in the acute phase, and the subsequent decrease in BMIPP uptake in the subacute phase.PubMedGoogle Scholar
- 23.Of importance Kawai Y, Morita K, Nozaki Y, et al.:Diagnostic value of 123I-betamethyl-p-iodophenyl-pentadecanoic acid (BMIPP) single photon emission computed tomography (SPECT) in patients with chest pain. Comparison with rest-stress 99mTc-tetrofosmin SPECT and coronary angiography.Circ J 2004,68:547–552. This study was a prospective clinical investigation of patients admitted for chest pain correlating BMIPP uptake with rest perfusion scintigraphy and coronary angiography; 74% of patients with documented coronary artery stenosis or vasospasm demonstrated a BMIPP defect.PubMedCrossRefGoogle Scholar
- 24.Hashimoto A, Nakata T, Nagao K, et al.: [Prediction of left ventricular functional recovery in patients with acute myocardial infarction using single photon emission computed tomography with thallium-201 and iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid].J Cardiol 1995,26:59–68.PubMedGoogle Scholar
- 43.Kawai Y, Morita K, Nozaki Y, et al.:Diagnostic value of 123I-betamethyl-p-iodophenyl-pentadecanoic acid (BMIPP) single photon emission computed tomography (SPECT) in patients with chest pain. Comparison with rest-stress 99mTc-tetrofosmin SPECT and coronary angiography.Circ J 2004,68:547–552.PubMedCrossRefGoogle Scholar