Abstract:
Objective: To validate ECG-based, post-myocardial infarction (post-MI) estimation of non-viable myocardium through Technetium-99m methoxyisobutylisonitrile single photon emission computed tomography (Tc-99m MIBI SPECT). Study Design: Retrospective, diagnostic accuracy study. Place and Duration of Study: Nuclear Cardiology Department, Armed Forces Institute of Cardiology & National Institute of Heart Diseases (AFIC & NIHD), Rawalpindi, from Nov 2018 to Feb 2019. Methodology: This retrospective, diagnostic accuracy study employing consecutive sampling included 142 postMI patients referred for SPECT myocardial perfusion imaging (MPI). Patients with history of non-ST elevation MI (NSTEMI), bundle branch blocks and unclear/abnormal ECG were excluded. After initial scrutiny, test outcomes data from 105 finally selected patients who underwent the index test (12-lead ECG) and the gold/reference standard (SPECT MPI) were analyzed through 2x2 contingency table. Results: Age and gender distribution in selected patients (n=105) showed an age range of 29 to 90 years (mean age = 58.16 years ± 10.69) and male to female ratio of 6:1 (90 males and 15 females). A 2x2 contingency table was used to compute different 12-lead ECG (index test) parameters. Calculated values were - Sensitivity (Sn) = 56.25%, Specificity (Sp) = 36.58%, Positive predictive value (PPV) = 58.06%, Negative predictive value (NPV) = 34.88% and Accuracy = 48.57%. Conclusion: 12-lead ECG - on validation against SPECT MPI - was found to be a bad test for estimation of nonviable myocardium in post-MI patients.
Page(s):
464-469
DOI:
DOI not available
Published:
Journal: Pakistan Armed Forces Medical Journal, Volume: 69, Issue: 3, Year: 2019
Keywords:
Myocardial Infarction
,
SPECT
,
ECG
,
Viable myocardium
,
Single photon emission computed tomography
,
Sensitivity and specificity