Dipyridamole thallium scintigraphy

ABSTRACT

Intravenous dipyridamole scintigraphy was performed in 100 cases with suspected or diagnostic coronary heart disease who were unable to exercise. Side effects were few of no clinical significance and disappeared following IV theophylline. Positive thallium scintigraphy was found in 55 cases, 31 had transient uptake defect, 17 had persistent defects and a combined uptake defects were present in 7 cases. The frequency of dipyridamole induced ST segment changes as well as the scintigraphic uptake defects were high in patients with history of typical anginal pain compared to those with atypical chest pain [p < 0.05, p < 0.05, respectively]. Persistent uptake defects diagnostic of myocardial infarction were found in 10 out of 14 patients [70%] in whom the diagnosis of myocardial infarction was inconclusive by history or electrocardiographic changes. Transient ischemic uptake defects were detected in 2 of 6 cases of recent MI [33%] and in 2 out of 9 cases of old MI [22%] denoting residual associated myocardial ischemia. Our study concluded that dipyridamole thallium scintigraphy imaging is a practically safe procedure. Its few side effects are reversible by IV theophylline. It provides a great diagnostic and prognostic value in patients with coronary artery unable to exercise and may thus serve as a useful alternative diagnostic modality to physical exercise