Impact of Myocardial Reperfusion Status on QT Dispersion After Successful Recanalization of the Infarct‐Related Artery in Acute Myocardial Infarction

Objective To determine whether adequate myocardial perfusion status after transluminal recanalization is associated with prompt improvement of QT dispersion (QTd). Background Transluminal recanalization of the infarct-related coronary artery in acute myocardial infarction aims to promptly restore myocardial perfusion, to maximize electrical and mechanical recovery. QTd represents the heterogeneity of ventricular repolarization, which may affect electrical stability. Methods Forty patients who underwent primary percutaneous coronary intervention for their first anterior acute ST-elevation myocardial infarction were prospectively enrolled. Myocardial reperfusion status was assessed by myocardial blush grade (MBG) on the final angiogram after successful recanalization (Thrombolysis In Myocardial Infarction Grade 3 flow). Results Preprocedural QTd was similar in patients with final MBG 0–1, 2, and 3 (76 ± 24, 67 ± 13, and 69 ± 13 milliseconds, respectively; P = 0.661). After recanalization, QTd decreased in patients with MBG 3 (39 ± 16 milliseconds, P < 0.001) but not in patients with MBG 0–1 (74 ± 20 milliseconds) or MBG 2 (82 ± 16 milliseconds). Multivariate analysis showed that postprocedural MBG was an independent predictor of QTd after recanalization (standardized regression coefficient = –0.628, P < 0.001). Conclusions Adequate tissue perfusion may be crucial for electrical stability of the myocardium after reperfusion. (J Interven Cardiol 2014;27:252–259)