Effects of nitroglycerin by technetium-99m sestamibi tomoscintigraphy on resting regional myocardial hypoperfusion in stable patients with healed myocardial infarction.
Myocardial sestamibi uptake reflects regional flow distribution and cellular integrity; however, some segments showing reduced tracer uptake at rest may consist of viable, although hypoperfused, myocardium. It is speculated that the administration of nitroglycerin (NTG) before the sestamibi injection would improve the tracer uptake in resting hypoperfused regions. Thirty-six stable patients with previous myocardial infarction (56 +/- 2 years; mean ejection fraction 42 +/- 2%), in whom perfusion defects could be seen at resting sestamibi tomography, repeated the scintigraphic study 2 to 6 days later, receiving NTG (0.3 to 0.6 mg sublingually) before the tracer injection. The size of the tracer uptake defect was quantified from circumferential profiles in 3 short-axis slices by integrating the area below the lower normal limit (mean -2 SD). After NTG, the mean perfusion defect significantly decreased (from 6,324 +/- 619 to 5,365 +/- 516, p < 0.01). The defect was reduced beyond the reproducibility limits in 20 patients (56%, group 1) and was unchanged or increased in 16 (44%, group 2). The resting sestamibi defect size was comparable between the 2 groups. The average percent reduction of the perfusion defect after NTG was 29 +/- 4% (range 7 to 74).(ABSTRACT TRUNCATED AT 250 WORDS)
Division of Cardiology and Nuclear Medicine, Clinica del Lavoro Foundation IRCCS, Medical Center of Rehabilitation of Veruno, Italy.
M
M
Galli
C
C
Marcassa
A
A
Imparato
R
R
Campini
P S
PS
Orrego
P
P
Giannuzzi
D003326:Coronary Circulation / Q000187:drug effects*; D004452:Echocardiography; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D005996:Nitroglycerin / Q000494:pharmacology; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D017256:Technetium Tc 99m Sestamibi
D017256:Technetium Tc 99m Sestamibi; D005996:Nitroglycerin