Applicability of small endomyocardial biopsies for evaluation of high energy phosphates and glycogen in the heart.
To evaluate variability of biochemical determination of energy stores in endomyocardial biopsies, we compared myocardial contents of high energy phosphates and glycogen in endomyocardial and transmural myocardial biopsies from 12 75-kg pigs before, during, and after cardioplegia. Before cardioplegia, comparable amounts of adenine nucleotides and glycogen were found in left and right ventricular endomyocardial and left ventricular transmural biopsies. Phosphocreatine levels were lower in endomyocardial than in transmural biopsies. Significant correlations were observed between endomyocardial and transmural adenine nucleotide and glycogen contents but not phosphocreatine content. During cardioplegia, myocardial ATP and phosphocreatine contents increased and glycogen concentration tended to decrease. During reperfusion, ATP and glycogen levels decreased, whereas phosphocreatine levels increased remarkably. Transmural changes in left ventricular adenine nucleotide and glycogen levels were reflected in endomyocardial biopsies but those in phosphocreatine were not. By increasing the number of endomyocardial biopsies from one to three, within-subject variance was reduced from 33-47% to 14-23% of total variance whereas four or more biopsies only added minor further reduction in variability. In conclusion, endomyocardial biopsies yield representative estimates of the average myocardial content of adenine nucleotides and glycogen but not of phosphocreatine in the normal heart. Endomyocardial biopsies offer a sensitive estimate of the changes in myocardial adenine nucleotides and glycogen induced by cardioplegia and reperfusion. However, metabolite content in endomyocardial biopsies shows a high variability. Three or more endomyocardial biopsies are necessary to reduce variability to acceptable levels.
Bøtker
H E
HE
Department of Cardiology, Skejby Hospital, University Hospital in Aarhus, Denmark.
Kimose
H H
HH
Thomassen
A R
AR
Nielsen
T T
TT
D000227:Adenine Nucleotides / Q000032:analysis*; D000818:Animals; D001706:Biopsy / Q000379:methods; D004699:Endocardium / Q000737:chemistry / Q000473:pathology*; D004734:Energy Metabolism; D005260:Female; D006003:Glycogen / Q000032:analysis*; D006324:Heart Arrest, Induced; D006352:Heart Ventricles / Q000737:chemistry / Q000473:pathology; D008297:Male; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000737:chemistry / Q000473:pathology; D010725:Phosphocreatine / Q000032:analysis*; D015203:Reproducibility of Results; D013552:Swine
D000227:Adenine Nucleotides; D010725:Phosphocreatine; D006003:Glycogen