Quantification of myocardial hypoperfusion with 99mTc-sestamibi in patients undergoing prolonged coronary artery balloon occlusion

Abstract

Percutaneous transluminal coronary angioplasty provides an excellent opportunity to investigate the location and quantity of hypoperfusion during sudden complete occlusion of one of the major coronary arteries. Thirty-five patients referred for elective percutaneous transluminal coronary angioplasty were injected intravenously with 99mTc-sestamibi during balloon inflation. To visualize and quantify the hypoperfused region, a map of perfusion was constructed from that occlusion study and from the control study performed on the following day. Patients were divided into groups according to proximal or distal occlusion within each of the three coronary arteries. The region of myocardium supplied by each coronary artery varied in location and extended outside the typical borders for all arteries, but most prominently for the left circumflex coronary artery. The quantities of hypoperfusion varied within each artery group, but the average hypoperfusion was greater for the left anterior descending coronary artery than for either the right coronary artery or the left circumflex coronary artery. It is concluded that the quantities of hypoperfusion were highly variable within each artery group. Occlusion of the left anterior descending coronary artery was associated with the largest ischaemic region. The area of hypoperfusion extended outside the typical borders, most prominently for the left circumflex coronary artery.

Evaluation of depolarization changes during acute myocardial ischemia by analysis of QRS slopes

“…Using filtered backprojection with a Butterworth filter transverse sections were reconstructed, without attenuation correction. Short axis sections were reconstructed for further analysis (23).…”

“…Any loss of perfusion during the PCI study compared to the control study was determined by an automatic procedure by comparing the bull´s eye plot of the 2 studies for each patient (23), and expressed as both extent and severity of the myocardial ischemia, as described earlier (14).…”

“…Reduction of perfusion by 25% or more was used as the threshold for indicating significantly hypoperfused myocardium (23). This area in the bull´s eye plot was delineated as an "extent map", representing all added slices (or volume) of the left ventricular (LV) myocardium, expressed as a percentage of the LV and defining the extent of ischemia.…”

“…This area in the bull´s eye plot was delineated as an "extent map", representing all added slices (or volume) of the left ventricular (LV) myocardium, expressed as a percentage of the LV and defining the extent of ischemia. The total pixel count difference (or local perfusion loss) between the control and occlusion study within this delineated hypoperfused area in the "extent map" was the severity and expressed as a percentage of the total pixel count in the control situation within the same area (23). The extent and severity of the ischemia were calculated for each patient.…”

Advances in Magnetic Resonance Imaging of the Myocardial Area at Risk and Salvage

“…Nordlund et al 17 also set out to compare their results with previous publications on identifying the culprit artery using single photon emission computed tomography. 18,19 The CMR image analyses were performed in a core laboratory using software designed by the same group in the University of Lund, Sweden. The CMR findings from assignment of the culprit artery territory were compared with the reference findings from the invasive coronary angiogram, taking into account the Rentrop collateral grade and infarct assessment using late gadolinium enhancement imaging with CMR.…”