title: Potassium-induced conversion of ventricular fibrillation after aortic declamping.
abstract: OBJECTIVE
  The anti-fibrillatory effect of potassium is well recognized from experimental models. There have, however, been very few clinical reports on the use of potassium to convert ventricular fibrillation (VF) after cardioplegic arrest.
  
  
  METHODS
  In total, 8465 adult patients undergoing cardiac operations on cardiopulmonary bypass (CPB) and with cold antegrade crystalloid cardioplegic arrest were consecutively enrolled in a database. Patients with VF after removal of the aortic clamp were given 20 mmol potassium, and if needed an extra 10 mmol, in the perfusion line and the conversion rate was registered. Preoperative and intraoperative factors possibly related to the occurrence of post-ischaemic VF were assessed.
  
  
  RESULTS
  Of these, 1721 (20%) patients had VF and 1366 of these (79%) were successfully treated with potassium infusion. Only 355 (21%) patients (4% of all operations) had direct-current countershock. The need for pacing was lower in the treatment group compared with the non-treatment group (P <0.001). Multivariate analysis revealed as the main findings that age, gender, amount of cardioplegia related to body mass index (BMI), and blood transfusion during the time of CPB had a highly significant (P <0.001) impact on reducing the rate of post-arrest VF. Somewhat contrary to expectation, left ventricular hypertrophy (LVH) was not a significant factor (P = 0.32) for post-arrest VF. No conversion by potassium was significant for age (P <0.001), gender (P <0.001) and LVH (P <0.001), but not for blood transfusion during CPB (P = 0.38) and for the ratio of cardioplegia-BMI (P = 0.26).
  
  
  CONCLUSIONS
  The results from this register study demonstrate that potassium infusion is an effective and convenient first-hand measure to convert post declamping VF on CPB.
authors.affiliation: Department of Cardiac Surgery, Feiring Heart Clinic, Feiring, Norway. sven.m.almdahl@unn.no
authors.forename: Sven M
authors.initials: SM
authors.lastname: Almdahl
authors.forename: Jens
authors.initials: J
authors.lastname: Damstuen
authors.forename: Magne
authors.initials: M
authors.lastname: Eide
authors.forename: Per
authors.initials: P
authors.lastname: Mølstad
authors.forename: Per
authors.initials: P
authors.lastname: Halvorsen
authors.forename: Terje
authors.initials: T
authors.lastname: Veel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage*; D001011:Aorta / Q000601:surgery*; D001639:Bicarbonates / Q000008:administration & dosage; D002122:Calcium Chloride / Q000008:administration & dosage; D002304:Cardiac Pacing, Artificial; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D016009:Chi-Square Distribution; D003250:Constriction; D004554:Electric Countershock; D005260:Female; D006324:Heart Arrest, Induced / Q000009:adverse effects*; D006801:Humans; D007262:Infusions, Intravenous; D016015:Logistic Models; D008274:Magnesium / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011189:Potassium Chloride / Q000008:administration & dosage; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D012965:Sodium Chloride / Q000008:administration & dosage; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000889:Anti-Arrhythmia Agents; D001639:Bicarbonates; C041711:St. Thomas' Hospital cardioplegic solution; D012965:Sodium Chloride; D011189:Potassium Chloride; D008274:Magnesium; D002122:Calcium Chloride