This study will assess the incidence, effect and persistence of F-QRS (Fragmented-QRS) in STEMI (ST-elevation Myocardial Infarction) patients post-PCI (percutaneous coronary intervention). The aim is to add to the existing research field surrounding F-QRS. It is hypothesised that patients with F-QRS present on the surface ECG, following PCI, will have incurred a higher degree of damage. As a result, it is hypothesised that these patients will have reduced LV (left-ventricular) systolic function, increased incidence of regional wall motion abnormalities (RWMAs), and increased troponin levels on admission. This study will additionally look for correlations between F-QRS and culprit vessels. To our knowledge there is minimal research regarding this.

This is a Physiological - Retrospective data collection from STEMI patients. Data from 100 STEMI patients treated with primary PCI will be extracted.

Data will be collected from presentation / initial admission, 6-week post-MI (Myocardial Infarction) clinic and 6 month post-MI clinic from the hospital system at New Cross Hospital. Data from admission includes; 12-lead ECG, echo reports and blood test results. Additionally, the 12-lead ECGs undertaken at 6-week and 6-months will be assessed for the presence of F-QRS.

Inclusion Criteria:

• Look back to data at least 12 months old in order to ensure 6-week and 6-month follow up data is available. The inclusion criteria will be patients that presented with STEMI and were treated with primary PCI.

Exclusion Criteria:

• From the cath lab reports and clinical letters exclusions apply to patients that did not present with STEMI. In addition, patients that were not treated with primary PCI, or patients that deceased prior, during or post procedure (during hospitalization).

100 STEMI patients treated with primary PCI.

No IPD will be available to other researchers