Analysis of the relationship between myocardial ischemia and left ventricular function after adenosine vasodilator stress by GSPECT

Objectives To evaluate the relationship between myocardial ischemia and the change of left ventricular ejection fraction after adenosine vasodilator stress by gated SPECT.

Methods We studied 70 patients referred for clinically indicated aden- -osine and rest gated single photon emission computed tomography(GSPECT). Coronary angiography was performed in all patients. Semiquantity assessment of perfusion was analysed in 17 left ventricular segments of left ventricular, segmental uptake scores were added to produce the summed rest score (SRS) and summed stress score(SSS), and the summed difference score (SDS) was calculated as the difference of SSS and SRS (SDS=SSS -SRS). The left ventricular function parameters(LVEF,LVEDV and LVESV) were quantified by QGS.

Results All patients were divided into two groups: 26 with reversible perfusion defects (reversible defect group) and 44 patients with normal LV perfusion (normal group). In patients with reversible perfusion defects demonstrated depressed post-adenosine LVEF (LVEF ado:61±19% and EF rest 66±21%) and volume dilation(LVEDV: 79±35ml after adenosine versus 74±33ml at rest; LVESV: 35±25ml after adenosine versus 30±26ml at rest)( P<0.05); In normal group LVEF ado,LVEDV ado,LVESV ado and LVEF rest,LVEDV rest,LVESV rest were not significantly different (69±15%,72±42ml,27±33ml and 70±15%,70±38ml,25±32ml) (P>0.05). Moreover, in patients with extensive reversible perfusion defects (SDS≥8), the number of patients with a significant decrease in post-adenosine LVEF (≥5%) was more than the patients without ischemia (P=0.036), and the severity of coronary artery stenosis was more serious(P<0.05). The patients with a significant decrease in post-adenosine LVEF (≥5%) had a more serious coronary artery stenosis than the other patients, but this difference had no statistically significant(P>0.05).

Conclusions The patients with extensive myocardial ischemia always demonstrated decrease in post-adenosine LVEF, and the depressed of post-adenosine LVEF has a positive correlation with CAD