In patients with acute ST elevation myocardial infarction treated with primary percutaneous coronary intervention :Does the QT- Dispersion correlate with myocardial perfusion?

Author(s): Marina Samir Roshdy, Hatem Helmy Abdelrahman*, Hosam Hasan Ali

Abstract Background: Improvement of QT dispersion has been shown after thrombolytic therapy in the treatment of ST elevation myocardial infarction. Change in QT dispersion and myocardial reperfusion after Primary Percutaneous Coronary Intervention was not well studied before as well as its relationship with myocardial blush grade after PPCI and the occurrence of major adverse cardiac events. Aim: The current study aimed to evaluate the relationship between QT dispersion and degree of myocardial reperfusion in patients with STEMI treated by PPCI as well as its relationship with the occurrence of MACE. Patients and Methods: A prospective, study included 200 patients admitted to Assiut University Heart Hospital with STEMI underwent PPCI. Myocardial reperfusion was assessed by Thrombolysis in myocardial infarction flow grade, myocardial blush grade and corrected TIMI frame count as well as QT parameters before and after PPCI in ECG. Patients were followed up for one-year after discharge for development of MACE. Results: Out of 200 patients; 125/200 had LAD culprit and 75/200 had non-LAD culprit. There was significant decrease after revascularization in minimum QTc, maximum QT and QT dispersion, patients with LAD as culprit lesion had significantly higher maximum QTc and QT dispersion after PCI in comparison to those with non-LAD culprit lesion; 52 /200 (22.5%) developed MACE. It was noticed that QT dispersion after PPCI was higher in those who developed MACE. Conclusion: Shortening of corrected QT and QT dispersion can help as simple electrocardiographic markers in predicting successful myocardial revascularization. Changes in maximum QT are better in predicting optimum revascularization as assessed by TIMI flow grade 3 and MBG than the changes in QT dispersion. These changes can also help in predicting lower MACE after one year in STEMI patients treated by PPCI.