View clinical trials related to QT Interval.
Filter by:Aim of the study is to determine the presence and direction of electrocardiographical changes of cardiac repolarization after thoracic paravertebral block, depending on block laterality. Injection of local anaesthetic into paravertebral space (paravertebral block, PVB) temporarily impairs transmission in nerve fibers in proximity of the deposition site. In case of PVB covering the rami of upper thoracic spinal nerves, among the others thoracic sympathetic cardiac nerves are blocked, possibly affecting action potential time of heart, especially the repolarization, and the related electrocardiographic phenomena. The risk of life-threatening polymorphic ventricular tachycardia (torsade des pointes, TdP) is associated with certain electrocardiographical symptoms, like QT interval prolongation and increased transmural repolarization dispersion (TDR). Determining the presence and direction of cardiac repolarization changes after a thoracic PVB will allow to conclude about its impact on TdP risk: protective or, contrary, arrhythmogenic.
Pooling effort to collect previously reported data on QTc time in former preterm neonates, and compare these data to controls. At present and based on a recently conducted systematic search, there are conflicting data on the potential QT interval prolongation (all Bazett) in former extreme low birth weight (ELBW, <1000 g) infants or preterms. Consequently, if investigators truly want to assess the presence or absence of either a difference or a prolongation of QTc intervals in this specific population, pooling of published data is likely the most effective approach (potential number of cases = 24 + 49 + 93 = 166; potential number of controls in the same studies = 24 + 53 + 87 = 164), preferably based on individual data. Although the sample is to a large extent pragmatic (as available), the investigators hereby aim to target the 5 ms QTc prolongation applied by the authorities (FDA, EMA) in paired healthy adult volunteer studies as 'golden' standard as primary outcome variable [EMA guideline, FDA guidance].