The Journal of Thoracic and Cardiovascular Surgery, Vol 76, 173-177, Copyright © 1978 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Evaluation of lactate dehydrogenase isoenzyme patterns in serum of patients undergoing cardiac surgery
NM Papadopoulos and CA Hufnagel
Serial determinations of serum lactate dehydrogenase (LD) isoenzymes were
performed in 50 patients undergoing cardiac surgery for coronary artery
bypass and heart valve replacement. A sequence of LD isoenzyme patterns was
established in the patients with uncomplicated recovery. These patterns
served as controls for the detection of abnormal patterns associated with
clinical complications. Perioperative myocardial infarction was detected in
seven patients by a characteristic reversal of the LD1:LD2 ratio. These
studies established that accurate determination of LD isoenzymes improved
their diagnostic specificity. These isoenzymes were determined by (1) using
the same technique for tissues and for serum samples, (2) applying a volume
of serum containing a standard amount of enzymatic activity, and (3) making
a clear separation, which allows accurate quantitation. This test can
provide useful information to the surgeon for the evaluation of operative
procedures and to the clinician for the appropriate management of the
patient undergoing cardiac surgery.
