The significance of transient left ventricular dilation during SPECT dipyridamole thallium-201 scintigraphy.

We assessed the significance of transient left ventricular dilation (TLVD) during single photon emission computed tomography (SPECT) dipyridamole thallium-201 scintigraphy (DTS) in 49 patients who underwent both DTS and diagnostic coronary arteriography. Quantitative analysis of DTS images and independent review by 3 experienced observers determined that 17 patients had TLVD and 32 patients had no TLVD. Patients with TLVD were similar to patients without TLVD with respect to age, history of myocardial infarction, coronary risk factors and occurrence of chest pain or electrocardiographic changes during DTS. The frequency of three-vessel coronary artery disease (3VD) was greater in patients with TLVD than in patients without TLVD (94% vs. 16%, p < 0.01). The sensitivity of TLVD was 76% and the specificity 96% for the detection of 3VD. Of the 16 patients with 3VD who manifested TLVD, standard SPECT DTS analysis demonstrated defect or perfusion abnormalities in 14 patients and no abnormalities in 2 patients. In conclusion, the finding of TLVD during SPECT DTS is a specific marker for severe coronary disease and can provide additive information to standard SPECT thallium-201 analysis.