Clinical research in cardiology : official journal of the German Cardiac Society
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A prolongation of the corrected QT interval (QTc) in the routine ECG of otherwise healthy neonates has been suspected to be a risk factor for sudden infant death. None of the studies published so far differentiated between awake and sleeping neonates. ⋯ Changes of the corrected QT interval in neonates seems to be dependent on the lead position of ambulatory ECGs, and could be found only in one lead. Guide values for the sleeping and awake neonate are provided.
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Post-cardiac arrest myocardial dysfunction is a common phenomenon after return of spontaneous circulation (ROSC) and contributes to hemodynamic instability and low survival rates after cardiac arrest. Mild hypothermia for 24 h after ROSC has been shown to significantly improve neurologic recovery and survival rates. In the present study we investigate the influence of therapeutic hypothermia on hemodynamic parameters in resuscitated patients and on contractility in failing human myocardium. ⋯ Contraction and relaxation kinetics are prolonged with hypothermia, indicating increased Ca(2+) sensitivity as the main mechanism responsible for inotropy. In conclusion, mild hypothermia stabilizes hemodynamics in cardiac arrest survivors which might contribute to improved survival rates in these patients. Mechanistically, we demonstrate that hypothermia improves contractility in failing human myocardium most likely by increasing Ca(2+)-sensitivity.