title: [A study of the variations in myocardial perfusion induced by systemic thrombolysis in acute myocardial infarct using sequential scintigraphy with 201-thallium].
abstract: To assess scintigraphic changes induced by intravenous streptokinase therapy, serial rest redistribution thallium-201 perfusion imaging was performed in 62 patients with acute myocardial infarction lasting less than 6 hours. Twenty-seven patients randomized to treatment with intravenous streptokinase (group A) and 35 to conventional therapy (group B) underwent thallium-201 scintigraphy as soon as possible after admission to the coronary care unit (early study). Regional myocardial perfusion was assessed using thallium-201 scintigraphy 7-9 days later in each patient (late study). The size of the perfusion defect was evaluated using a semi-quantitative score. The size of the perfusion defect decreased in serial scans in both group A (preintervention score: 12.1 +/- 6.8; redistribution score: 11.4 +/- 6.8; late study: 8.8 +/- 7.0) and group B (12.8 +/- 6.5; 12.3 +/- 6.7; 10.6 +/- 7.5, respectively). No statistical difference in myocardial perfusion was found between the two groups, on late study. Peak serum creatine kinase MB (CKMB) was earlier in group A than in group B (1030.8 +/- 326.6 vs 1361.0 +/- 271.1: p less than 0.001). The fast CKMB release group (onset of symptoms-peak of CKBM less than or equal to 900 minutes) exhibited higher thallium-201 uptake when compared to the slow CKMB release group, at the time of late study (perfusion defect score: 6.1 +/- 5.7 vs 10.7 +/- 7.3: p = 0.03). Reversibility was observed in 21/62 patients (34%). Reversibility corresponded to unchanged or improved perfusion defect score on late study in 18/21 patients (86%). Nevertheless 20/41 (49%) patients not showing redistribution of thallium-201 within pre-treatment defect had an improvement in regional perfusion on late study. Reversibility was observed in 9/14 (64%) patients with fast CKMB release and in 12/47 (26%) patients with slow CKMB release. We conclude that the early peak of CKMB is associated with a higher uptake of thallium-201 on late study. Furthermore, the reversibility of perfusion defect on redistribution imaging forecasts evolution of scintigraphic perfusion, but, when this is not present, it doesn't rule out late improvement of thallium-201 myocardial uptake. The low sensitivity and specificity of redistribution imaging and the procedure related delay in instituting therapy make thallium-201 scintigraphy unreliable in the evaluation of myocardial reperfusion following thrombolysis.
authors.affiliation: Divisione di Cardiologia, Ospedale S. Croce, Cuneo.
authors.forename: C
authors.initials: C
authors.lastname: Bruna
authors.forename: A
authors.initials: A
authors.lastname: Biggi
authors.forename: N
authors.initials: N
authors.lastname: Debenedictis
authors.forename: F
authors.initials: F
authors.lastname: Meinardi
authors.forename: G
authors.initials: G
authors.lastname: Rossetti
authors.forename: G
authors.initials: G
authors.lastname: Ugliengo
authors.forename: A
authors.initials: A
authors.lastname: Vado
authors.forename: B
authors.initials: B
authors.lastname: D'Angeli
authors.forename: C
authors.initials: C
authors.lastname: Farinelli
authors.forename: G
authors.initials: G
authors.lastname: Camuzzini
mesh_terms: D000328:Adult; D000368:Aged; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000000981:diagnostic imaging* / Q000188:drug therapy; D015425:Myocardial Reperfusion / Q000379:methods*; D011877:Radionuclide Imaging; D013300:Streptokinase / Q000627:therapeutic use; D013794:Thallium Radioisotopes; D015912:Thrombolytic Therapy
chemical_list: D007527:Isoenzymes; D013794:Thallium Radioisotopes; D003402:Creatine Kinase; D013300:Streptokinase
vernacular_title: Studio delle variazioni di perfusione miocardica indotte dalla trombolisi sistemica nell'infarto miocardico acuto mediante scintigrafia sequenziale con tallio 201.