Electrocardiography (ECG) parameters are significant in the prognosis of ischemia and other cardiovascular conditions. Reperfusion or revascularization techniques are essential in reestablishing blood flow to ischemic tissues. This study aims to demonstrate the association between percutaneous coronary intervention (PCI), a revascularization technique, and the electrocardiography (ECG) parameter, QT dispersion (QTd). We conducted a systematic review of the association between PCI and QTd through a literature search in three electronic databases, ScienceDirect, PubMed, and Google Scholar, for empirical studies published in English. Review Manager (RevMan) 5.4 (Cochrane Collaboration, Oxford, England) was used for statistical analysis. Of 3,626 studies, 12 articles met the inclusion criteria, enrolling a total of 1,239 patients. After a successful PCI procedure, QTd and corrected QT (QTc) tremendously reduced at various time intervals with statistical significance in most of the studies. There was a clear association between ECG parameters QTd, QTc, and corrected QT dispersion (QTcd), and PCI, in that there is a considerable reduction in these ECG parameters after PCI treatment.