Assessment of hemodynamic abnormalities during exercise with stress thallium-201 myocardial scintigraphy

In 30 patients with angiographically documented ischemic heart disease, initial thallium-201 myocardial images were divided into six segments and thallium-201 activity was visually assessed for each region by three-point scoring system. Delayed images were analyzed for the presence of redistribution (Rd) on hypoperfused segments, i. e., scintigraphic evidence of transient myocardial ischemia. Based on clinical and scintigraphic findings, patients could be divided into three main groups which consisted of large defect group (defect score>=4), samall defect (defect score<=3) with anginal pain (AP group) and small defect without anginal pain (OMI group). Furthermore, patients with OMI group could be subdivided into two subgroups by the presence or absence of Rd in the infarcted area. Each group was compared with hemodynamic parameters during exercise and following results were obtained. Patients with large defect had significantly higher mean pulmonary artery wedge pressure (PAWP) (p<0.001) and lower left ventricular stroke work index (LVSWI) during exercise than those with small defect. Of patients with small defect, patients with AP group had significantly higher mean PAWP (p<0.02) and lower LVSWI (p<0.005) than those of OMI group despite nearly identical defect score. Moreover, patients with OMI and positive Rd in the infarcted area had significantly higher mean PAWP (p<0.02) than those without Rd. Some patients with OMI, however, showed discrepancy between electrocardiographic and scintigraphic findings of myocardial ischemia. (J.P.N.)