Comparative assessment of rest and post-stress left ventricular volumes and left ventricular ejection fraction on gated myocardial perfusion imaging (MPI) and echocardiography in patients with transient ischaemic dilation on adenosine MPI: Myocardial stunning or subendocardial hypoperfusion?
Journal of Nuclear Cardiology, 05/29/2012
Emmett L et al. – Transient dilation of the left ventricle on adenosine MPI is not related to chamber enlargement and myocardial stunning, but is more likely a function of subendocardial hypoperfusion and impaired coronary flow reserve.Methods
- 31 patients undergoing single–day Tc–99m adenosine sestamibi MPI were recruited.
- All had routine ECG–gated single–day rest–stress adenosine MPI, with transthoracic echocardiograms (echo) acquired concurrently at rest, and both immediately, and 2 hours, post–stress.
- Echocardiography was performed using a Vivid–7 (GE).
- LV volumes and LVEF were quantified blinded to MPI results, using biplane Simpson method on echo, and quantitatively (including TID) with QGS, on MPI.
- Patients were divided into quartiles for TID, with the top quartile considered TID positive [TID+ 9/31 (TID ratio 1.3 ± 0.09)], and TID negative [TID– 22/31 (TID ratio 1.01 ± 0.04)].
- There was good correlation between resting echo and MPI physical measurements (LVEDV r 2 = 0.79, LVESV r 2 = 0.9, and LVEF r 2 = 0.75).
- On MPI, a significant drop in LVEF was observed between rest and early stress in the TID+ group (56.6% vs 46.5%, P < .002), as well as an increase in both LVESV (62 vs 79 mls, P < .0001) and LVEDV (113 vs 131 mls, P < .0001).
- However, no statistically significant change in LVEF, LVESV or LVEDV was identified on concurrent echo imaging (LVEF 57% vs 56%, P < .66; LVESV 48 vs 54 mls, P < .26; LVEDV 87 vs 97 mls, P < .299).
- No significant change in LVEF or ventricular volumes was noted in the TID– group by either echo or MPI.