Effect of potassium infusion on the human conduction system.
His bundle electrograms were recorded in 12 patients before and after the intravenous administration of 5 mEq of potassium. Antegrade and retrograde refractory periods were determined with the extrastimulus technique. The AH interval was 84 +/- 7 msec before and 89 +/- 7 msec after potassium (P < 0.05). The AH interval at an atrial pacing rate of 140/minute was 129 +/- 13 msec before and 143 +/- 16 msec after potassium (P < 0.02). The effective refractory period of the atrium was 264 +/- 9 msec before and 280 +/- 9 msec after potassium (P < 0.001). Thus small amounts of potassium delay conduction at the atrial and AV nodal level.
D000368:Aged; D001283:Atrioventricular Node / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002036:Bundle of His / Q000187:drug effects; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000187:drug effects; D006329:Heart Conduction System / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000008:administration & dosage*
D011188:Potassium