Prolonged T-T interval is associated with ventricular fibrillation during reperfusion in ST-elevation myocardial infarction.

AIM

Ventricular fibrillation (VF) during reperfusion in ST-elevation myocardial infarction (STEMI) is associated with increased in-hospital mortality. Dispersion of ventricular repolarization contributes to ventricular vulnerability during ischemia. T-T interval was proposed as a ventricular repolarization dispersion marker, however its value for prediction of reperfusion VF remains uncertain. We aimed to assess whether T-T before PCI in STEMI is associated with reperfusion VF.

METHODS

STEMI patients admitted for primary PCI were retrospectively assessed for VF during reperfusion. Pre-PCI ECGs recorded in 40 patients with reperfusion VF (rVF group; age 65 ± 13 years, 80% male) were compared with 374 consecutive patients without reperfusion arrhythmias (No-rVF group; age 67 ± 12 years; 68% male). Digital ECGs were automatically processed and T-T interval computed on a per-lead basis. The global T-T was calculated between the earliest T and the latest T in any lead, and tested for association with reperfusion VF using logistic regression analysis.

RESULTS

The leftward shift of T toward QRS complex in ischemic leads resulted in T-T prolongation. Global T-T in rVF group was higher than in No-rVF group (142 ± 24 vs 130 ± 27 ms; p = 0.007). Global T-T ≥ 131 ms predicted reperfusion VF (OR = 3.41; 95% CI 1.66-7.04; p = 0.001) and remained a significant predictor of reperfusion VF in multivariable analysis.

CONCLUSION

T-T interval before PCI in STEMI was an independent predictor of reperfusion VF. Our findings warrants further research aimed at prospective validation of T-T as a marker of periprocedural arrhythmic risk.