The Predictive Value of Fragmented QRS and QRS Distortion for High-Risk Patients with STEMI and for the Reperfusion Success.

Background: QRS fragmentation (fQRS) and QRS distortion were separately shown to be related to increased cardiovascular mortality and morbidity. To our knowledge, no study so far evaluated both parameters together in ST segment elevation myocardial infarction (STEMI). The main goal of our study is to find out if fQRS and QRS distortion can help us to determine high-risk STEMI patients, and the success of reperfusion.

Methods: Two hundred forty-eight eligible patients with acute STEMI that underwent coronary angiography consecutively between January 1, 2009, and July 1, 2011, were enrolled in this study. Twelve-lead electrocardiography (ECG) of the patients taken in the first 48 hours were analyzed. Patients with fQRS formed group 1, without fQRS formed group 2; with QRS distortion formed group 3, and without QRS distortion formed group 4.

Results: Group 1 have lower left ventricular ejection fraction (LVEF; P < 0.001), higher maximum troponin levels (P < 0.001), lower ST segment resolution (P < 0.001), more frequent proximal lesions (P < 0.001) when compared to group 2. Similar findings were observed in group 3 in comparison to group 4. Group 1 had also more frequent three vessels disease (P < 0.001), and higher rates of failed thrombolysis (P < 0.001). In-hospital mortality was found to be higher in group 1 and group 3.

Conclusion: fQRS and QRS distortion may be useful for identifying patients at higher cardiac risk. fQRS can foresee thrombolytic therapy failure and three vessels disease whereas QRS distortion does not possess such quality. These findings may guide the physician deciding initial treatment modality in STEMI.