Role of 99mTc-sestamibi gated SPECT/CT myocardial perfusion imaging in the management of patients with myocardial bridging and its correlation with coronary angiography.

Myocardial bridging (MB)-a congenital coronary abnormality in its severe form leads to myocardial edema, fibrosis, and ischemia due to coronary artery compression during systole and early part of the diastole. This study evaluated the hemodynamic significance of MB by detecting severity and extent of perfusion abnormality using 99mTc-sestamibi (MIBI) gated single photon emission computed tomography (SPECT)/CT myocardial perfusion imaging (MPI), its correlation with coronary angiography and role in patient's management. Five patients with complaints of atypical chest pain, exertional angina, or dyspnea underwent stress/rest 99mTc-MIBI SPECT/CT MPI. The gated stress and rest SPECT/CT images on 17 segment model using quantitative gated-SPECT (QGS) softwarewere analyzed and compared with coronary angiography. Four out of five patients showed reversible perfusion defect in the left anterior descending (LAD) territory segments involved with myocardial bridging (3 patients had already proven MB; while MB was detected in 1 patient after MPI). The fifth patient with MB in the distal LAD revealed normal myocardial perfusion. All the patients were conservatively managed either due to small reversible perfusion defects or normal study except one patient. The gated SPECT/CT MPI of five patients with MB in the present study revealed their perfusion status, information on myocardial wall thickening, contractility, and ejection fraction. <Learning objective: Myocardial bridging may be one of the underlying causes for angina or sudden death even in absence of cardiovascular risk factors. The proven or clinical suspicious myocardial bridging in patients with typical/atypical chest pain and low probability of atherosclerosis should be evaluated with gated SPECT/CTMPI. It helps in detection of coronary artery disease along with severity and extent of myocardial ischemia for their further management.>.