Progressive loss of perfusion-contraction matching during sustained moderate ischemia in pigs.
It is unclear whether perfusion-contraction matching (PCM) is maintained during prolonged myocardial ischemia. In 27 anesthetized pigs, left anterior descending coronary arterial inflow was reduced to decrease an anterior work index (WI) at 5 min of hypoperfusion by 40% and then maintained at this level for 12 or 24 h. With 12 h of hypoperfusion, the myocardium remained viable in 6 of 7 pigs (with triphenyltetrazolium chloride; TTC) and with 24 h of hypoperfusion in 5 of 11 pigs (TTC, histology). The reduction in WI to 62 +/- 4 and 62 +/- 3% of baseline in the two groups was matched to the reduction of transmural blood flow (TBF; microspheres) at 5 min of hypoperfusion, averaging 59 +/- 4 and 60 +/- 2% of baseline. With prolonged hypoperfusion, WI decreased to 30 +/- 5% at 12 h and 18 +/- 3% at 24 h; TBF remained unchanged (53 +/- 4 and 54 +/- 4%). The added calcium concentration required for the half-maximal increase in WI increased from 121 +/- 25 microg/ml blood at baseline to 192 +/- 26 microg/ml blood at 12 h of hypoperfusion. Thus, with hypoperfusion for 24 h, PCM is progressively lost, and calcium responsiveness is reduced.
Schulz
R
R
Abteilung für Pathophysiologie, Zentrum für Innere Medizin des Universitätsklinikums Essen, 45122 Essen, Germany.
Post
H
H
Neumann
T
T
Gres
P
P
Lüss
H
H
Heusch
G
G
D000818:Animals; D002118:Calcium / Q000097:blood / Q000493:pharmacokinetics; D002135:Calcium-Binding Proteins / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002155:Calsequestrin / Q000378:metabolism; D002470:Cell Survival; D003326:Coronary Circulation / Q000502:physiology*; D005260:Female; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000378:metabolism; D020287:In Situ Nick-End Labeling; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology; D009200:Myocardial Contraction / Q000502:physiology*; D017682:Myocardial Stunning / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D010101:Oxygen Consumption / Q000502:physiology; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D015996:Survival Rate; D013556:Swine, Miniature; D014336:Troponin / Q000378:metabolism; D016276:Ventricular Function / Q000502:physiology; D000099211:Phospholamban
D002118:Calcium; D002135:Calcium-Binding Proteins; D000252:Calcium-Transporting ATPases; D002155:Calsequestrin; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D014336:Troponin; D000099211:Phospholamban