Short-term variability in QT interval and @entity943 induced by XXXX are dependent on high-frequency autonomic oscillations.

@entity4033 @entity2781 @entity2198 @entity3529 @entity1 @entity1166 @entity235 @entity5434 @entity9493 @entity943
BACKGROUND AND PURPOSE: The present study was undertaken to investigate an effect of @entity2781 , a potent arrhythmic blocker of the voltage-gated @entity3529 channel, @entity9493 , on cardiac autonomic control. Combined with effects on ardiomyocytes, these properties could influence its arrhythmic potency. EXPERIMENTAL APPROACH: The short-term variability of beat-to-beat QT interval (STVQT ), induced by @entity2781 is a strong surrogate of @entity1166 . Involvement of autonomic modulation in STVQT was investigated in healthy @entity5434 and @entity235 by power spectral analysis under conditions of autonomic blockade with @entity4033 . KEY RESULTS: Increase in STVQT induced by @entity2781 in monkeys and @entity235 was closely associated with an enhancement of endogenous heart rate and @entity2198 . These effects were fully suppressed under conditions of autonomic blockade with @entity4033 . @entity943 , including @entity1166 in monkeys, were prevented in both species @entity2198 were suppressed by autonomic blockade. Similar enhancements of heart rate @entity2198 were found in @entity235 with other @entity9493 blockers described as causing @entity1166 in @entity1 . CONCLUSIONS AND IMPLICATIONS: These results demonstrate for the first time that beat-to-beat ventricular repolarization variability and @entity943 induced by @entity2781 are dependent on endogenous HF autonomic oscillations in heart rate. When combined with evidence of @entity9493 -blocking properties, enhancement of endogenous @entity2198 in heart rate could constitute an earlier and more sensitive biomarker than STVQT for @entity1166 , applicable to preclinical regulatory studies conducted in healthy animals.
