Open AccessSequential Alterations in Myocardial Lactate Metabolism, S-T Segments, and Left Ventricular Function During Angina Induced by Atrial Pacing
Author(s) -
John O. Parker,
Miguel A. Chiong,
Roxroy O. West,
Robert B. Case
Publication year - 1969
Publication title -
circulation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.795
H-Index - 607
eISSN - 1524-4539
pISSN - 0009-7322
DOI - 10.1161/01.cir.40.1.113
Subject(s) - medicine , cardiology , angina , coronary artery disease , hemodynamics , electrocardiography , myocardial infarction
Myocardial lactate metabolism was monitored before, during, and after a period of atrial pacing with a continuous automated sampling technic. The electrocardiogram was recorded, and left ventricular function was evaluated by relating left ventricular end-diastolic pressure to left ventricular stroke work. Seventeen of 21 patients with coronary artery disease experienced angina during pacing, and 13 of these showed lactate production by the myocardium during angina. The abnormalities in lactate metabolism developed early in the pacing period, along with S-T segment depression and impairment of left ventricular function, all of which usually occurred before the onset of pain. In the patients with angina, the mean lactate extraction was 14.1% during the control period and —15.1% during the pacing period. Abnormalities in myocardial lactate metabolism have been demonstrated with greater regularity during pacing-induced angina than during angina precipitated by exercise or isoproterenol. This investigation has demonstrated the sequences of changes in lactate metabolism during and after a period of angina and their relation to electrocardiographic and hemodynamic events.