[Enzymatic and scintigraphic determined infarct size: significance for left ventricular function following infarct]

In a prospective study, the relationship between extent and location of myocardial infarction and the resulting left ventricular dysfunction was assessed and the question asked, how well these parameters may be assessed non-invasively a few weeks after the acute event. One hundred and fifty survivors of a first myocardial infarction were studied in the acute stage by serial ECG and CPK recordings and 5 weeks later by thallium201-(Tl)-scintigraphy and radionuclide angiocardiography. Myocardial damage was assessed enzymatically (maximal CPK; CPKmax) in the acute phase and scintigraphically in the subacute phase using a Tl-score considering extent (in percent of total myocardium in each projection) and severity (decrease in thallium-uptake) of scintigraphic infarct defects. There were significant correlations between Tl-score and max. CPK (r = .69) as well as between Tl-score and left ventricular ejection fraction (LVEF) (r = .65; p less than .001 each), but this correlation was better for subgroups with anterior vs. inferior infarctions (r = -.68 vs. r = -.59; p less than or equal to .001 for each). Furthermore, LVEF could be predicted based on the Tl-score: 88% of patients with values less than 7 had an LVEF of greater than 45%, whereas 77% of patients with a thallium-score of more than 12 had an LVEF less than 45%. Reproducibility of the Tl-score assessed in 30 patients over 3 months was excellent (r = .96) with low variability between the two analyses (+/- 1.5). Thus, after a first myocardial infarction, a direct relationship between enzymatically and scintigraphically, assessed infarct size and LVEF could be demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)