The usefulness of fQRS and QRS distortion for predicting reperfusion success and infarct-related artery patency in patients who underwent thrombolytic therapy

BACKGROUND: The aim of this study is to determine whether the presence of fragmented QRS (fQRS) and QRS distortion on admission ECG can be used to predict the success of treatment before beginning thrombolytic therapy (TT). PATIENTS AND METHODS: Two hundred and three eligible patients with acute ST elevation myocardial infarction who received TT consecutively between 1 January 2009 and 1 July 2013 were enrolled. The presence of fQRS and QRS distortion was analyzed at admission ECG. The electrocardiographic criteria of reperfusion were defined as 50% or more of ST resolution (STR), whereas the angiographic criteria of reperfusion were defined as thrombolysis in myocardial infarction 2/3 flow in the infarct-related artery. RESULTS: fQRS was detected in 63 (31%) patients. Compared with patients with non-fQRS, STR was lower (46.1±17.7 vs. 73.6±20.9, respectively; P<0.001), thrombolysis failure was higher (44.4 vs. 9.3%, respectively; P<0.001), and thrombolysis in myocardial infarction 0/1 flow was more common (39.7 vs. 10.7%, respectively; P<0.001) in patients with fQRS. Higher numbers of fQRS derivations were significantly related to low percentages of STR (r=-0.615, P<0.001). In predicting occluded infarct-related artery, we found no difference between the negative predictive values of fQRS and inadequate STR after TT (89.3 vs. 95.1%; P>0.05). However, there was no relationship between QRS distortion and failed thrombolysis. CONCLUSION: fQRS was detected in just 31% of the patients, but we found that it can be used to predict thrombolytic failure. Patients who have this simple marker on admission ECG may be directed to percutaneous interventions as a first-line therapy without any delay.