Relation of global and regional left ventricular function to tomographic thallium-201 myocardial perfusion in patients with prior myocardial infarction

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To determine the relation between regional myocardial perfusion and regional wall motion in humans, tomographic thallium-201 imaging and two-dimensional echocardiography at rest were performed on the same day in 83 patients 4 to 12 weeks after myocardial infarction. Myocardial perfusion and wall motion were assessed independently in five left ventricular regions (total 415 regions). Regional myocardial perfusion was quantitated as a percent of the region infarcted (range 0 to 100%) using a previously validated method. Wall motion was graded on a four point scale as 1 = normal (n = 266 regions), 2 = hypokinesia (n = 64), 3 = akinesia (n = 70), 4 = dyskinesia (n = 13) or not evaluable (n = 2).Regional wall motion correlated directly with the severity of the perfusion deficit (r = 0.68, p < 0.0001). Among normally contracting regions, the mean perfusion defect score was only 2 ± 4. Increasingly severe wall motion abnormalities were associated with larger perfusion defect scores (hypokinesia = 6 ± 5, akinesia = 11 ± 7 and dyskinesia = 18 ± 5, all p < 0.01 versus normal). Among regions with normal wall motion, only 3% had a perfusion defect score ≥ 10. Conversely, among 68 regions with a large (≥ 10) perfusion defect, only 13% had normal motion whereas 87% had abnormal wall motion. The relation between perfusion and wall motion noted for the entire cohort was also present in subgroups of patients with anterior or inferior infarction.In patients with prior myocardial infarction, the severity of the tomographic thallium perfusion defect correlates directly with echocardiographically defined wall motion abnormalities, both globally and regionally. Hypokinetic regions have an intermediate reduction in perfusion compared with normally contracting or akinetic-dyskinetic regions. The combination of techniques described in this report may prove useful in the noninvasive evaluation of therapy designed to improve both regional perfusion and function.