Background. Few data are available regarding the incidence and significance of transient left ventricular (LV) dilation on stress sestamibi single photon emission computed tomography (SPECT), which is different from thallium-201 studies because images are acquired late after tracer injection. Methods. We studied 234 patients with ischemic heart disease and interpretable electrocardiograms undergoing stress-rest sestamibi SPECT on separate days. Sestamibi uptake defect extent was quantified on SPECT polar maps. Epicardial and endocardial transient dilation indexes (TDI) were also calculated. Results. According to our normal TDI values, 148 patients (63%) had no dilation and 86 patients (37%) had abnormal endocardial TDI; a global LV dilation (abnormal endocardial and epicardial TDI) was observed in 19 patients (8%). ST-segment depression was more frequent in patients with transient LV dilation (55%) than in those without (36%; P <.01), as were the extent of stress hypoperfusion (13% ± 12% vs 6% ± 7% in patients with no dilation; P <.001) and the angiographic severity score (11.4 ± 5.9 vs 9.2 ± 3.7; P <.05). At multivariate analysis, stress hypoperfusion was the sole predictor of transient LV dilation. Conclusions. Transient LV cavity dilation is frequent on stress sestamibi SPECT. Ventricular cavity dilation is more common than global dilation and suggests subendocardial ischemia. It is related to a greater amount of jeopardized myocardium and is strongly associated with electrocardiographic signs of ischemia.
- Stress testing
- Ventricular dilation
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine