title: QTc prolongation after brain surgery.
abstract: OBJECTIVE
  Abnormalities observed in the electrocardiogram (ECG) after acute central nervous system (CNS) events have been reported. Our objective was to assess the incidence of heart rate-corrected QT interval (QTc) prolongation in patients admitted to the intensive care unit (ICU) after brain surgery.
  
  
  METHODS
  Admission standard 12-lead ECGs were analyzed blinded to patient data. The QT interval was measured and Bazzett's formula was used to obtain QTc. Prolonged QTc was defined as ≧450 ms.
  
  
  RESULTS
  We included 114 patients in the study. The mean age was 49±17 years. Brain neoplasm was the surgical indication in 90% of the patients. The mean QTc was 470±42 ms. Prolonged QTc was found in 71% patients. The heart rate-corrected QT interval was between 450 ms and 500 ms in 52% and >500 ms in 19% of the patients. The heart rate and concentration of serum glucose were higher in the prolonged QTc group. Only 7·5% of all patients had hypokalemia (≤3 mEq/l). In the prolonged QTc group 9·2% had hypokalemia compared to 3·2% in normal QTc patients (P = 0·406). There were no significant associations between categories of QTc and the serum levels of creatinine, magnesium, calcium, sodium, or pH. Phenytoin and metoclopramide were not frequently used in patients with prolonged QTc.
  
  
  CONCLUSIONS
  This study supports our hypothesis that prolonged QTc is frequently observed after a brain surgery. Hypokalemia, hypocalcaemia, and drugs such as metoclopramide or phenytoin could not explain the high incidence of prolonged QTc. Brain injury during a surgical procedure may be one of the primary causes of QTc prolongation after neurosurgery.
authors: Intensive Care Unit, Internal Medicine Department, Raul Carrea Institute for Neurological Research FLENI, Buenos Aires C1428AQK, Argentina.
authors: Federico J
authors: FJ
authors: Capparelli
authors: Mauricio
authors: M
authors: Abello
authors: L
authors: L
authors: Patricio Maskin
authors: Eugenia
authors: E
authors: Arista
authors: Alejandro
authors: A
authors: Hlavnicka
authors: Maria Fernanda
authors: MF
authors: Diaz
authors: Daniel
authors: D
authors: Varela
authors: Nestor A
authors: NA
authors: Wainsztein
mesh_terms: D000927:Anticonvulsants / Q000009:adverse effects; D000932:Antiemetics / Q000009:adverse effects; D001118:Argentina / Q000453:epidemiology; D001786:Blood Glucose / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000601:surgery*; D002118:Calcium / Q000097:blood; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007008:Hypokalemia / Q000453:epidemiology; D015994:Incidence; D008133:Long QT Syndrome / Q000453:epidemiology*; D008274:Magnesium / Q000097:blood; D008297:Male; D008787:Metoclopramide / Q000009:adverse effects; D008875:Middle Aged; D010672:Phenytoin / Q000009:adverse effects; D011183:Postoperative Complications / Q000453:epidemiology*; D012964:Sodium / Q000097:blood
chemical_list: D000927:Anticonvulsants; D000932:Antiemetics; D001786:Blood Glucose; D010672:Phenytoin; D012964:Sodium; D003404:Creatinine; D008274:Magnesium; D008787:Metoclopramide; D002118:Calcium