The usefulness of p-wave dispersion to determine reperfusion and infarct related artery patency in acute myocardial infarction patients who received thrombolytic therapy

SUMMARY Introduction and Aim: The value of P-wave dispersion (PWD) on the surface electrocardiogram was showed to be increased in coronary ischemia. It was also showed in the previous studies that PWD was decreased with repefusion therapy in acute STEMI. The aim of this study is to investigate whether PWD is able to be used as an additional parameter to predict successful reperfusion and infarct related artery patency in patients with acute STEMI who admitted in the first 12 hours and received thrombolytic therapy. Methods: 150 patients were included to our study who admitted Dokuz Eylül University Cardiology department with acute STEMI between 01 January 2010 and 01 December 2011 and received thrombolytic therapy in the first 12 hours of the symptoms. Data was evaluated retrospectively. Demographical features, routine laboratory parameters were recorded. Standart 12-lead surface electrocardiograms of each patient were obtained which were taken before and at 30, 60, 90 and 120 minutes after the start of thrombolytic therapy. Maximum, minimum P-wave duration and PWD were calculated on each electrocardiogram and ST segment resolution was determined. Also coronary angiography images were evaluated to determine TIMI flow grade and TIMI frame count of the infarct related artery. The relationship between PWD and ST segment resolution and infarct related artery patency was investigated. Results: While PWD at the start of the thrombolytic therapy (TT) was 50.79±14.12 ms, PWD at 90th minute of TT was calculated as 48.34±15.60 and PWD at 120th minute of TT was calculated as 47.85±10.87 ms, the difference was not statistically significant (p= 0.07). When PWD values compared with ST segment resolution groups, PWD at 120th minute of TT was found to be significantly lower in complete resolution group than incomplete and inadequate resolution groups (42.10±9.55, 49.65±10.60, 56.08±7.44 ms respectively; p<0.001). PWD at 120th minute of TT was found to be significantly lower in the patients whose TIMI frame count ? 40 (adequate reperfusion) than those whose TIMI frame count >40 (inadequate reperfusion) (46.12±10.87 ms vs. 51.83±10.11 ms; p=0.005). But, there was no significant relationship between PWD values measured during TT and the TIMI flow grade groups. A ? 46 ms PWD value at 120th minute of TT was determined to be a predictor of inadequate reperfusion of infarct related artery with %65 sensitivity and %43 specifity. Conclusion: PWD values not decreasing with thrombolytic therapy in acute STEMI patients, can serve as a marker of failed reperfusion in combination with ST segment resolution. Key Words: P-wave dispersion, thrombolytic therapy, ST elevated myocardial infarction, ST segment resolution