The relationship between the electromechanical window and ventricular arrhythmia prevalence in HFrEF patients with ICD.

AIM: The electromechanical window (EMW) refers to the time interval between aortic valve closure and the end of the T-wave during the same cardiac cycle. Recent studies highlight the role of EMW in assessing the risk of ventricular arrhythmia. This study examines the predictive value of the EMW for ventricular arrhythmias in heart failure with reduced ejection fraction (HFrEF) patients with an implantable cardioverter defibrillator (ICD).

MATERIALS AND METHODS: This single-centre study included 52 HFrEF patients with ICD. The patients were divided into two groups based on the presence or absence of anti-tachycardia pacing (ATP) or shock therapy during ICD interrogation: those without therapy (n = 28) and those with therapy (n = 24). EMW duration was measured by echocardiography. The groups were compared with sex and age-matched controls (n = 24).

RESULTS: The groups were homogeneous in terms of age and sex. EMW was lower in the ICD therapy group compared to without therapy and control groups (-25.17 ± 31.5 vs. 0.61 ± 25.1 vs. 9.21 ± 21.1; respectively, p < 0.001), while ECG-QTc duration did not differ between groups (p = 0.053). An EMW value below -22.5 ms demonstrated 69% sensitivity and 79% specificity in predicting ventricular fibrillation (AUC: 0.766, 95% CI 0.598-0.935), 57% sensitivity and 83% specificity in predicting ATP/shock therapy (AUC: 0.722, 95% CI 0.577-0.866), 67% sensitivity and 82% specificity in predicting shock therapy (AUC: 0.770, 95% CI 0.620-0.921).

CONCLUSION: EMW is an up-to-date parameter easily measured with echocardiography. Our study shows that negative extension of EMW is a valuable predictor of ventricular arrhythmias and ICD therapies.