The relationship between T-wave peak-to end interval and ST segment recovery on intracoronary ECG during primary PCI.

Objective: T-wave peak to end interval (TPE) is a measure of repolarization dispersion, which has been reported as a major arrhythmogenic factor post acute myocardial infarction. The aim of our study was to investigate the changes in TPE in this patient population with regard to peri-procedural intracoronary ECG findings.

Patients And Methods: Forty-four patients (34 male and mean age of 54.9 ± 10.9 years) with acute STEMI were included. Intracoronary ECG was performed during primary PCI. TPE indices were calculated before and after the procedure. Measurement of the intracoronary ST-segment was carried out before and just after coronary blood flow was established in the infarct related artery. Intracoronary ST-segment resolution (IC-STR) was defined as ≥ 1 mm compared to baseline.

Results: There was no difference with respect to baseline characteristics when patients with IC-STR were compared with patients without IC-STR. TPE values decreased significantly after primary PCI in patients with IC-STR (80.9 ± 22.8 ms vs. 65.8 ± 14.4 ms; p < 0.001) whereas they did not change significantly after PCI in patients without IC-STR (79.2 ± 20.9 ms vs. 68.5 ± 16.3 ms; p = 0.18).

Conclusions: TPE measured from surface ECG recordings is significantly reduced in STEMI patients with successful reperfusion after primary PCI, as determined by IC-ECG recordings.