title: Continuous vectorcardiography in cardiac surgery: natural course of vector changes and relationship to myocardial oxygen uptake.
abstract: Continuous vectorcardiography was registered before and during the first 18 hours after cardiac surgery in 53 patients. QRS vector changes (QRS-VD) occurred during the operation, but no further changes were observed postoperatively. The ST vector (ST-VM) increased during the operation, and a further slight increase occurred postoperatively. Perioperative myocardial infarction occurred in three patients. Their ST-VM was higher than the average in patients without myocardial infarction, while QRS-VD did not differ from the average pattern. Twelve other patients were studied in pacemaker-induced moderate tachycardia. QRS-VD increased in proportion to heart-rate changes (rs median = 0.93, p less than 0.01). QRS-VD also correlated with myocardial oxygen uptake (rs median = 0.62, p less than 0.05). The ST-VM responses were not uniform. The data suggest that vectorcardiogram variables can provide information related to myocardial energy metabolism.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, University Hospital, Uppsala, Sweden.
authors.forename: O
authors.initials: O
authors.lastname: Wesslén
authors.forename: R
authors.initials: R
authors.lastname: Ekroth
authors.forename: P O
authors.initials: PO
authors.lastname: Joachimsson
authors.forename: L
authors.initials: L
authors.lastname: Nordgren
authors.forename: S O
authors.initials: SO
authors.lastname: Nyström
authors.forename: H
authors.initials: H
authors.lastname: Tydén
mesh_terms: D000328:Adult; D000368:Aged; D001026:Coronary Artery Bypass; D004562:Electrocardiography; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000378:metabolism / Q000503:physiopathology*; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption; D014672:Vectorcardiography / Q000379:methods