title: Transient decrease in serum potassium level during ischemic attack of acute coronary syndrome: paradoxical contribution of plasma glucose level and glycohemoglobin.
abstract: BACKGROUND
  Although a decrease in serum potassium level has been suggested to be a fairly common observation in acute coronary syndrome (ACS), there have so far been no definitive reports directly demonstrating the transient potassium decrease (the potassium dip) during ischemic attack of ACS compared to stable phase in individual patients. To understand the pathophysiological significance of the potassium dip, we examined the changes in serum potassium level throughout ischemic attack and evaluated the clinical factors affecting it.
  
  
  METHODS
  The degree of the potassium dip during ischemic attack (as indicated by ΔK, ΔK = K at discharge - K on admission) was examined in 311 consecutive patients with ACS who required urgent hospitalization in our institution.
  
  
  RESULTS
  Serum potassium level during ischemic attack was significantly decreased compared to that during stable phase (P < 0.001). Multiple regression analysis revealed that plasma glucose level during attack was the sole factor which was positively correlated with ΔK (P < 0.01), while HbA1c level was negatively correlated (P < 0.05). The medication profiles and renal function had no impact on ΔK. A longer hospitalization period, higher incidence of myocardial infarction and higher peak creatine kinase level were observed in patients with a larger ΔK.
  
  
  CONCLUSIONS
  We have clearly demonstrated that there is a transient decrease in serum potassium level during ischemic attack of ACS compared to stable phase. The degree of the potassium dip was tightly correlated with glucose level, which overwhelmed the diabetic condition, and it also indicates the disease severity. The present study therefore promotes awareness of the significance of monitoring potassium level in parallel with glucose level in patients with ACS.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo, 105-8461, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sekiyama
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Nagoshi
authors.forename: Kimiaki
authors.initials: K
authors.lastname: Komukai
authors.forename: Masato
authors.initials: M
authors.lastname: Matsushima
authors.forename: Daisuke
authors.initials: D
authors.lastname: Katoh
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ogawa
authors.forename: Kosuke
authors.initials: K
authors.lastname: Minai
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ogawa
authors.forename: Michihiro
authors.initials: M
authors.lastname: Yoshimura
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D011188:Potassium / Q000097:blood*; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D011188:Potassium; C517652:hemoglobin A1c protein, human