Evaluation of post-stress left ventricular dysfunction and its relationship with perfusion abnormalities using gated SPECT in patients with cardiac syndrome X.
OBJECTIVE
Cardiac syndrome X defines patients with typical angina, a positive exercise ECG stress test and angiographically documented normal coronary arteries. In previous studies, post-stress prolonged left ventricular dysfunction (PLVD) using gated SPECT (G-SPECT) had been well correlated with myocardial perfusion abnormalities and degree of stenotic vessels in CAG in patients with coronary artery disease. However, evaluation of left ventricular myocardial perfusion, wall motion and left ventricular ejection fraction (LVEF) in patients with cardiac syndrome X, using G-SPECT had not been studied yet. Thus, the aim of this study was to analyse PLVD using (99m)Tc-MIBI GSPECT in patients with cardiac syndrome X.


METHODS
Of the patients in whom G-SPECT was performed in our institution between 2004 and 2006, 17 patients with anginal chest pain, positive exercise ECG stress test and normal coronary angiograms were retrospectively included to the study (group I). Fifteen patients with normal myocardial perfusion and another 15 patients with ischaemia on G-SPECT were selected as control groups (groups II and III). (99m)Tc-MIBI G-SPECT was performed for all patients according to 2 day (stress-rest) protocol. Stress and rest LVEF were derived automatically (SLVEF and RLVEF). Difference LVEF (DLVEF) (stress-rest) was calculated. Semiquantitative analyses were made both for myocardial perfusion and wall motion (WM), using a 20-segment model and a 5-point scoring system. DLVEF, perfusion and WM scores of all groups were compared among three groups and relationship between DLVEF, perfusion and WM scores were evaluated.


RESULTS
Abnormal perfusion were detected in eight (47.1%) of patients, while the remaining nine (52.9%) had normal myocardial perfusion, in group I. Six of 17 (35.3%) patients in group I had post-stress WM abnormalities. Mean of DLVEF values were -3.1+/-3.0%, 4.4+/-2.0% and -6.0+/-5.1% in groups I, II and III, respectively (P<0.05 for group II vs. group I and group III; P>0.05 for group I vs. group III). LVEF response impairment (< or =5% increase from rest to post-stress images) was found in 17 (100%), seven (46.6%), 14 (93.3%) of patients in groups I, II and III, respectively.


CONCLUSIONS
Abnormal myocardial perfusion, concordant transient segmental WM abnormalities and LVEF response impairment are not uncommon in patients with cardiac syndrome X of this cohort of the study population. Therefore, post-stress prolonged stunning may be attributed to these findings in some of cardiac syndrome X patients as in true ischaemic patients. However, further studies with larger number of subjects and long-term follow-up are necessary to support these findings.
Demir
Hakan
H
Department of Nuclear Medicine, Kocaeli University School of Medicine, Umuttepe Yerleskesi, Kocaeli, Turkey. hakandemir99@yahoo.com
Kahraman
Goksel
G
Isgoren
Serkan
S
Tan
Yusuf Ziya
YZ
Kilic
Teoman
T
Berk
Fatma
F
D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005080:Exercise Test; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D017566:Microvascular Angina / Q000000981:diagnostic imaging*; D008875:Middle Aged; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi