Objective Evidence of Inducible Ischemia in Patients with Ischaemic Heart Disease by Global Longitudinal Strain During Dobutamine Stress Echocardiography

ABSTRACT

Background: Operator dependent two-dimensional (2D) echocardiography is a noninvasive test to assess myocardial hypokinesia. Inter observer variability is more as it is subjective. Objective evidence of 2D global longitudinal strain (2D GLS) and strain rate imaging are getting popularity. Methods: This cross sectional study was done on 20 patients who came for dobutamine stress echo (DSE) in the department of cardiology of BSMMU, Dhaka from 1st February 2019 to 31st July 2019. 2D GLS was done before and just after DSE. Results: DSE findings revealed 6 patients had viable LAD, 9 had viable LCX and 6 had viable RCA, 9 had nonviable LAD, 2 had nonviable LCX and 3 had nonviable RCA territories. Difference in Post-systolic strain rate (SRps) in myocardial segments supplied by LAD at baseline peak stress in patients who had normal and nonviable LAD (-21% to. -23%, p=0.98) and (-6%to – 7%, p= 2.87) which were not significant. At peak exercise there was a trend towards greater SRps in viable territory of LAD in compared with baseline and peak stress (-1% to -16%, P = 0.05) which was significant. SRps in myocardial segments supplied by LCX at baseline and peak stress in patients who have normal and nonviable LCX (-20% to. -21%, p=0.82) and (-5%to – 5%, p=1.18) which had similar result as LAD territory. At peak exercise there was a trend towards greater SRps in viable territory of LCX compared with baseline and peak stress (-12% to -15%, P = 0.06). There was no significant difference in SRps in myocardial segments supplied by RCA at baseline and peak stress in patients who had normal and nonviable RCA (-23% to. -24%, p=1.72) and (-4%to – 5%, p=2.10). At peak exercise there was a trend towards greater SRps in viable territory of RCA compared with baseline and peak stress (-10% to -15%, P = 0.04). Conclusion: Results of subjective interpretation of DES has compared with objective evidence 2D GLS on peak stress which has similarity. It was a small study. Future large study is needed to establish these findings.