Muhammad Sohail Saleemi, Muhammad Tahir Mohyuddin, Nisar Ahmad, Fawad Qadir, Mubasher Ali Khan Sherwani, Zahid Rafique Butt.
Pathologic q-wave on ecg as a predictor of nonviable myocardium in post-myocardial infarction patients.
J Cardiovascular Dis Jan ;16(4):157-60.

OBJECTIVE: To determine the diagnostic accuracy of pathologic Q wave on ECG in predicting the presence of non-viable myocardium taking SPECT as gold standard. MATERIALS AND METHODS: This validation study enrolled 150 patients of myocardial infarction referred to the Department of Nuclear Medicine for evaluation of myocardium viability with EF <=50%, having age 30-70 years. The study duration was Oct-2019 to April-2020. 12 lead ECG was done to determine pathologic Q-waves on ECG. After ECG, all patients underwent SPECT scanning. SPECT was performed using Tc99 scanning protocol. Myocardium was considered non-viable if >10% of the LV myocardial tissue was found non-viable. RESULTS: Mean age was 53.57+-11.41 years. There were 124 (82.7%) male and 26 (17.3%) female patients. On ECG, pathologic Q-wave was present in 87 (58%) patients, while non-viable myocardium on SPECT was present in 110 (79.0%) patients. The sensitivity of Q-wave was 71.8%, specificity was 80.0%, PPV was 90.8% and NPV was 50.8%. Kappa statistics value was 0.43 which indicate moderate agreement. CONCLUSION: Pathologic Q-wave on 12 lead ECG have average sensitivity and specificity for the diagnosis of non-viable myocardium. So in facilities where SPECT imaging is available, the consultant should rely on the SPECT findings instead of pathologic Q-waves for determination of irreversible myocardial scarring. KEYWORDS: Pathologic Q-wave, Single photon emission computed tomography (SPECT), non-viable myocardium.

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