Abnormal ventricular wall motion was associated with significantly increased dispersion of repolarization compared to normal wall motion (84 ms vs 49 ms, p<0.005), independent of infarction.
Cross-Sectional (n=23)
Is abnormal ventricular wall motion associated with increased dispersion of repolarization in patients undergoing coronary artery surgery?
Abnormal ventricular wall motion is associated with increased repolarization inhomogeneity, independent of myocardial infarction, providing a potential electrophysiological mechanism for the increased arrhythmic risk observed in these patients.
Absolute Event Rate: 84% vs 49%
p-value: p=<0.005
Abnormal ventricular wall motion is a strong clinical predictor of sudden, arrhythmic, cardiac death. Dispersion in repolarization is a prerequisite for the initiation of re-entrant arrhythmia. We hypothesize that regionally decreased wall motion is associated with heterogeneity of repolarization. We measured local activation times, activation-recovery intervals (ARIs, surrogate for action potential duration), and repolarization times using a multielectrode grid at nine segments on the left ventricular epicardium in 23 patients undergoing coronary artery surgery. Regional wall motion was simultaneously assessed using intraoperative transesophageal echocardiography. Three groups were discriminated: (1) Patients with normal wall motion (n = 11), (2) Patients with one or more hypokinetic segments (n = 6), (3) Patients with one or more akinetic or dyskinetic segments (n = 6). The average ARI was similar in all groups (251 ± 3.7 ms, ±SEM). Dispersion of ARIs between the nine segments was significantly increased in the hypokinetic (84 ± 7.4 ms, p < 0.005) and akinetic/dyskinetic group (94 ± 3.5 ms, p < 0.0005) compared with the normal group (49 ± 5.1 ms), independent from the presence of myocardial infarction. Repolarization heterogeneity occurred primarily in the normally contracting regions of the hearts with abnormal wall motion. An almost maximal increased dispersion of repolarization was observed when there was only a single hypokinetic segment. We conclude that inhomogeneous wall motion abnormality of even moderate severity is associated with increased repolarization inhomogeneity, independent from the presence of infarction.
Opthof et al. (Sun,) conducted a cross-sectional in Patients undergoing coronary artery surgery (n=23). Abnormal ventricular wall motion (hypokinetic) vs. Normal ventricular wall motion was evaluated on Dispersion of activation-recovery intervals (ARIs) (p=<0.005). Abnormal ventricular wall motion was associated with significantly increased dispersion of repolarization compared to normal wall motion (84 ms vs 49 ms, p<0.005), independent of infarction.