The adenosine-triphosphate-sensitive potassium-channel opener pinacidil is effective in blood cardioplegia.
BACKGROUND
This study was designed to evaluate the adenosine-triphosphate-sensitive potassium channel opener pinacidil as a blood cardioplegic agent.


METHODS
Using a blood-perfused, parabiotic, Langendorff rabbit model, hearts underwent 30 minutes of normothermic ischemia protected with blood cardioplegia (St. Thomas' solution [n = 8] or Krebs-Henseleit solution with pinacidil [50 micromol/L, n = 81) and 30 minutes of reperfusion. Percent recovery of developed pressure, mechanical arrest, electrical arrest, reperfusion ventricular fibrillation, percent tissue water, and myocardial oxygen consumption were compared.


RESULTS
The percent recovery of developed pressure was not different between the groups (52.3 +/- 5.9 and 52.8 +/- 6.9 for hyperkalemic and pinacidil cardioplegia, respectively). Pinacidil cardioplegia was associated with prolonged electrical and mechanical activity (14.4 +/- 8.7 and 6.1 +/- 3.9 minutes), compared with hyperkalemic cardioplegia (1.1 +/- 0.6 and 1.1 +/- 0.6 minutes, respectively; p < 0.05). Pinacidil cardioplegia was associated with a higher reperfusion myocardial oxygen consumption (0.6 +/- 0.1 versus 0.2 +/- 0.0 mL/100 g myocardium/beat; p < 0.05) and a higher percent of tissue water (79.6% +/- 0.7% versus 78.6% +/- 1.2%; p < 0.05).


CONCLUSIONS
Systolic recovery was not different between groups, demonstrating comparable effectiveness of pinacidil and hyperkalemic warm blood cardioplegia.
Department of Surgery, Medical College of Virginia, Richmond, USA.
J S
JS
Lawton
P W
PW
Hsia
R J
RJ
Damiano
D000818:Animals; D002314:Cardioplegic Solutions; D004594:Electrophysiology; D005260:Female; D006146:Guanidines / Q000494:pharmacology*; D006321:Heart / Q000502:physiology; D006324:Heart Arrest, Induced; D066298:In Vitro Techniques; D008297:Male; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption; D020110:Pinacidil; D015221:Potassium Channels / Q000187:drug effects; D011817:Rabbits; D011897:Random Allocation; D014665:Vasodilator Agents / Q000494:pharmacology*
D002314:Cardioplegic Solutions; D006146:Guanidines; D015221:Potassium Channels; D014665:Vasodilator Agents; D020110:Pinacidil