Peak interlead T-wave heterogeneity significantly differentiated cases of ischemia-induced ventricular fibrillation from those without VF in both dog (563 vs 139 microV; P<0.01) and pig models.
Does interlead T-wave heterogeneity predict ischemia-induced ventricular fibrillation in animal models?
Heightened spatial heterogeneity of repolarization, measured by T-wave heterogeneity, underlies T-wave alternans and predicts increased risk for ischemia-induced ventricular fibrillation.
Absolute Event Rate: 563% vs 139%
p-value: p=<0.01
Oscillations in T-wave morphology, particularly T-wave alternans (TWA), have been fundamentally linked to increased susceptibility to ventricular fibrillation (VF). We investigated whether the escalation in complexity of T-wave oscillations before VF is attributable to increased spatial heterogeneity of repolarization. Peak interlead T-wave heterogeneity (TWH) was measured by second central moment analysis of T-wave morphology in epicardial electrograms in dogs during left anterior descending coronary artery occlusion. TWH differentiated cases in which myocardial ischemia provoked VF from those without VF (563 +/- 56 vs. 139 +/- 36 microV, P < 0.01). In the former group, progressive, significant increases in TWH above preocclusion baseline (70 +/- 8 microV) began at 2.25 min after the start of occlusion and were associated successively with TWA (at 155 +/- 19 microV), T-wave multupling (at 386 +/- 100 microV), complex oscillatory T-wave forms (at 560 +/- 76 microV), discordant TWA (at 572 +/- 98 microV), and VF at 4.36 +/- 0.14 min. TWH in precordial ECGs in 12 pigs during angioplasty-balloon-induced myocardial ischemia also discriminated animals that experienced VF (from 90 +/- 14 at baseline to 382 +/- 39 microV, P < 0.05) from those without VF (from 96 +/- 17 at baseline to 199 +/- 61 microV, NS). Ischemia-induced changes in ST segment and T-wave amplitude did not predict VF. Heightened spatial heterogeneity of repolarization, as assessed by second central moment analysis of TWH, underlies TWA and increased risk for ischemia-induced VF. Monitoring spatial TWH from precordial leads could prove useful in stratifying risk for life-threatening arrhythmias.
Nearing et al. (2003) studied Myocardial ischemia and ventricular fibrillation. Measurement of peak interlead T-wave heterogeneity (TWH) vs. Cases without ventricular fibrillation was evaluated on Peak interlead T-wave heterogeneity (TWH) in dogs (p=<0.01). Peak interlead T-wave heterogeneity significantly differentiated cases of ischemia-induced ventricular fibrillation from those without VF in both dog (563 vs 139 microV; P<0.01) and pig models.