| Summary: | Objectives: To determine the incidence and characteristics of myocardial perfusion abnormalities in patients with ST depression in recovery only, using Tc-99m gated-SPECT.
Background: The significance of ST depression in recovery only after exercise treadmill testing (ETT) remains controversial. Such finding has been classified as a false positive, false negative and inconclusive sign of CAD.
Methods: Fifty patients who underwent ETT and Tc-99m gated-SPECT and demonstrated ST depression only in recovery were analyzed. The group consisted of 28 men and 22 females, mean age of 61 ± 9 years. Perfusion abnormalities, reverse redistribution, heart/lung ratio, changes in LV cavity size and global function were assessed. Results: The mean peak heart rate (PHR) was 139 ± 18 bpm (88% ± 14 of the predicted maximal heart rate). Sixty % of the patients had
evidence of CAD in form of either fixed or reversible perfusion abnormalities. Fixed only perfusion abnormalities were found in 3 patients (6%), seven (14%) had fixed and reversible perfusion defects and 20 (40%) showed ischemia only. Ischemia was observed in the anterior wall in 10 patients, inferior wall in 12, lateral wall in 5, apex in 8 and septum in 1 patient. Mean extent of the perfusion abnormalities were 3.7 segments (out of 20) ± 2.
Conclusions: Evidence of CAD was found in 60% of the patients with ST depression in recovery only. The most common finding was ischemia in 54% of the patients, and the anterior and inferior walls were most frequently involved. The mean extent of myocardial involvement was moderate, which implies prognostic significance.
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