Significance of Wedensky Modulation testing in the evaluation of non-invasive risk stratification for ventricular tachyarrhythmia in patients with coronary artery disease and implantable cardioverter-defibrillator.

OBJECTIVE

Evaluation of the significance of the Wedensky Modulation (WM) examination for ventricular tachyarrhythmias (VT) in patients with coronary artery disease and implantable cardioverter-defibrillator therapy (ICD).

DESIGN

Prospective, single-centre study conducted from 2004 to 2006.

SETTING

University of Bonn, Department of Medicine - Cardiology, Bonn, Germany.

PATIENTS

37 consecutive patients with coronary artery disease receiving an ICD for primary or secondary prevention.

MAIN OUTCOME MEASURES

Correlation of a positive WM-Index (WMI) with established non-invasive Holter parameter, the occurrence of VT after ICD implantation with regard to primary or secondary prevention, and inducibility of VT during electrophysiological (EP) studies.

RESULTS

The WMI was positive in 15 patients (67 (SD 8) years, 31% (SD 12%) EF) and showed significant correlation with heart rate variability (standard deviation of normal to normal intervals (SDNN): 143 (SD 80) ms vs 102 (SD 29) ms, p = 0.04, r = 0.45; total power (TP). 11 885 (SD 19 674) ms(2) vs 2229 (SD 1779) ms(2), p = 0.03, r = 0.384; very low frequency component (VLF): 2777 (SD 3039) ms(2) vs 1184 (SD 565) ms(2), p = 0.03; low frequency component (LF): 2955 (SD 5734) ms(2) vs 468 (SD 725) ms(2), p = 0.05, r = 0.375; high frequency component (HF): 4885 (SD 9939) ms(2) vs 382 (SD 609) ms(2), p = 0.05, r = 0.315) and turbulence (turbulence onset (TO): -0.002 (SD 0.008) vs +0.005 (SD 0.01), p = 0.05, r = 0.301; turbulence slope (TS): 3.4 (SD 3.1) vs 1.7 (SD 1.5), p = 0.04, r = 0.419). The positive predictive value of the WMI considering the inducibility of VT during EP testing was 100%. Those patients who received an ICD for primary prevention showed a higher WMI (p = 0.049) than the secondary prevention group. With respect to the occurrence of adequate VT episodes, a negative WM test result demonstrated a negative predictive value of 95%.

CONCLUSION

The data presented show that the WM-Index predicts VT inducibility during EP testing and indicates a high negative predictive value regarding the occurrence of VT.