Gated myocardial perfusion SPECT in patients with left bundle block but having low probability of coronary artery disease; as compared to the patients with normal electrocardiogram
نویسندگان
1 Nuclear Medicine Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
2 Nuclear Medicine Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
3 Department of Cardiovascular Diseases, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
4 Department of Cardiovascular Diseases, Imam Reza Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
5 Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mshhad, Iran
6 Nuclear Medicine Research Center, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
doi
چکیده
Introduction: We aimed to investigate of effect of left bundle branch block (LBBB) on perfusion and functional parameters in dipyridamole Tc99m-MIBI gated myocardial perfusion SPECT which may be helpful in interpretation of myocardial perfusion imaging. Methods: We studied 70 patients with low pre-test probability of coronary artery disease in two groups: 35 patients with LBBB and 35 subjects with normal ECG. Both groups underwent two-day dipyridamole stress–rest Tc99m-MIBI GSPECT. Results: From 35 patients with LBBB, 6, 12, and 3 patients had reversible, fixed and partially reversible defects respectively. In 35 patients with LBBB, 8 (22.9%), 6(17.1%) 15( 42.9%) and 10 (28.6%) patients had perfusion defects in the apicoseptal, mid-anterior segments , mid-anteroseptal and mid-inferoseptal segments respectively. There was significant difference in TID ratio between two groups: LBBB group: 1.07±0.21 and control group: 0.96±0.14 (P=0.01). There was a significant difference in end systolic volume and ejection fraction between LBBB patients group and control group, while no significant difference was noticed in end-diastolic volume. Nineteen, 14 and 2 from 35 patients with LBBB had normal LV wall motion, paradoxical septal wall motion, and septal hypokinesia respectively. Conclusion: False positive septal, anterior and apicoseptal perfusion abnormalities are frequently seen on Tc99m-MIBI GSPECT, in patients with LBBB without CAD. Moreover reversible defects are frequently seen with Tc99m-MIBI. Even Tc99-MIBI and vasodilator stress do not increase diagnostic accuracy to clinically useful levels. Lower systolic performance and higher TID ratio could be seen in these patients.
