Nitroglycerin-Augmented ²⁰¹ Tl Reinjection Enhances Detection of Reversible Myocardial Hypoperfusion

Abstract

Nitrate-augmented 201Tl reinjection significantly, albeit modestly, improves detection of defect reversibility, especially in patients with coronary collateral circulation.

Single Photon Emission Computed Tomography (SPECT) Myocardial Perfusion Imaging Guidelines: Instrumentation, Acquisition, Processing, and Interpretation

“…This is particularly relevant to patients with evidence of collaterals by invasive coronary angiography. 144 Semiquantitative assessment. On rest, reinjection, or redistribution images, myocardial segments with normal perfusion or mild hypoperfusion (score 0 or 1) are viable; moderately hypoperfused segments (scores of 2) represent a combination of viable and nonviable myocardium; and severely hypoperfused segments (scores of C3) represent nonviable myocardium.…”

Coronary collaterals during single‐vessel coronary angioplasty: Effects of nitroglycerin

“…In humans, the effect of nitroglycerin on collateral function has mainly been assessed by means of scintigrams. 5,6 Scintigraphy, however, does not take into account improved myocardial perfusion secondary to nitroglycerin-induced cardiac unloading. [11][12][13] Piek et al found increased coronary collateral flow (Doppler wire technique) after injection of nitroglycerin into the donor coronary artery in patients with spontaneously visible collaterals (n = 24), but not in patients with recruitable collaterals (n = 11).…”

“…Although nitroglycerin has been suggested to dilate collateral vessels, most of this information comes from animal experiments or indirectly from perfusion studies in humans. [3][4][5][6] In this prospective study, we aimed to characterize patients with and without coronary collaterals and to evaluate the effects of systemic administration of nitroglycerin on both visible and recruitable coronary collaterals.…”

Myocardial viability assessment and utility in contemporary management of ischemic cardiomyopathy

“…5,8 Nitrate administration may further enhance the sensitivity of SPECT to detect VM. 17 SPECT imaging is easily available and lower cost as compared to PET imaging. While normal uptake of radioactive tracer confirms the viability of myocardium, absence of tracer uptake does not confirm nonviable, transmural myocardial scar, as discussed below.…”