The comparison of two gated SPET protocols: adenosine Tc-99m tetrofosmin and treadmill exercise Tc-99m MIBI.
BACKGROUND
The effect of adenosine and exercise on gated SPET left ventricular ejection fraction (LVEF), end diastolic volume (EDV) and end systolic volume (ESV) has not been fully investigated. The aim of the study was to compare functional measurements obtained in one-day adenosine rest and two-day stress-rest protocols in relation to ischaemia.


METHODS
Out of 226 consecutive patients examined with submaximal treadmill stress-rest 700 MBq Tc-99m MIBI, 26 were chosen to match those subjected to adenosine (140 micro g/kg/min) enhanced by a low level exercise protocol (300 MBq and 700 MBq Tc-99m tetrofosmin for stress and rest respectively). All images were acquired on a double head system and were gated using 8 frames, 25 s per frame.


RESULTS
ED and ES volumes increased after adenosine but decreased after treadmill resulting in the post-stress LVEF being significantly greater than after adenosine, 60 +/- 11 v. 51 +/- 13% (p < 0.01). This was caused by the smaller post-stress ESV in the treadmill group 40 +/- 20 v. 51 +/- 34, p < 0.05. In non-ischaemic scans the LVEF was greater (61 +/- 8 v. 51 +/- 14, p < 0.01) and EDV and ESV smaller after both stress and rest.


CONCLUSIONS
The adenosine test may have an opposite influence on the EDV and ESV in comparison to the submaximal treadmill test and therefore the left ventricular function measurements after adenosine infusion should be interpreted carefully and may not represent those acquired after physical exercise. In the gated SPET scans showing ischaemia the post-stress EDV and ESV may be greater and the LVEF lower than at rest.
Department of Internal Medicine and Cardiology, Central Hospital, Military Medical School, Warszawa, Poland. mdziuk@hotmail.com
Mirosław A
MA
Dziuk
Jacek
J
Pietrzykowski
Ana L
AL
Canizales
Keith E
KE
Britton
Marian
M
Cholewa
D000241:Adenosine; D000368:Aged; D005080:Exercise Test; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging*; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; 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 / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000209:etiology
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin; D017256:Technetium Tc 99m Sestamibi; D000241:Adenosine