Abstract 57: Effect of J Wave and QTc Prolongation on Mortality and Neurological Injury in Patients Undergoing Therapeutic Hypothermia Post Cardiac Arrest
Introduction: Early therapeutic hypothermia (TH) is standard of care to improve survival and neurological recovery in comatose cardiac arrest survivors. Electrocardiogram (ECG) changes during TH include prolongation of QT interval and development of J waves (Osborne waves). We reviewed patients who received TH to assess whether the development of QT prolongation or J waves was associated with neurologic injury and/or death.
Methods: This is a retrospective study of 45 patients who underwent TH after cardiac arrest between 2008 and 2013. QTc intervals and the presence of J waves were confirmed and extracted from ECGs proceeding, during and after completion of TH. In hospital mortality and sustained neurologic injury were collected from medical records. Neurological injury was quantified by using cerebral performance categories scale (CPC score). Favorable neurologic outcome was defined as CPC scores of 1-2 as they reflect good cerebral performance and moderate cerebral disability, respectively. Poor neurologic outcome was defined as CPC scores of 3-5 as they reflect severe cerebral disability, vegetative state, and brain death, respectively. Impact of J waves and QTc on in hospital mortality and neurologic injury was analyzed using logistic regression model.
Results: In this cohort, there were 24 deaths and 21 survivors. The presence of a J wave (n=14) did not have any impact on mortality at discharge [odds ratio (OR) 0.65 95% confidence interval (CI) 0.15 to 2.76 p=0.56]. QT prolongation occurred in 41 of 45 patients. QTc prolongation did not have any impact on outcome [OR 0.99 95% CI 0.97 to 1.01 p=0.24]. Over 62% of our patient cohort had poor neurologic outcome at discharge with a CPC score of 3, 4 or 5. Presence of a J wave or QTc prolongation did not have any impact on neurologic injury (OR 0.45 95% CI 0.11 to 1.88 p=0.27) and (OR 0.99 95% CI 0.98 to 1.02 p=0.67), respectively.
Conclusions: Therapeutic hypothermia induced ECG changes of QT prolongation and J waves were not associated with neurologic injury or death in this small sample population of cardiac arrest survivors. These findings warrant further investigation in a larger population.
Author Disclosures: N. Fonseka: None. P.U. Thanawala: None. M. Harari: None. G. Marhefka: None.
- © 2014 by American Heart Association, Inc.