Korean Circ J.  2001 Mar;31(3):359-359. 10.4070/kcj.2001.31.3.359.

Role of KATP Channel During Sustained Ventricular Fibrillation

• Kim YH
• Pak HN
• Kim SJ
• Hwang GS
• Lee SJ
• Shim WJ
• Oh DJ
• Ro YM

• KMID: 2145642
• DOI: http://doi.org/10.4070/kcj.2001.31.3.359

Abstract

OBJECTIVES
To investigate the role of ATP-sensitive potassium channel (KATP) during sustained ventricular fibrillation (VF), the effects of gliburide, a specific blocker of KATP channel and PCO400, an KATP opener, were studied in isolated and perfused swine right ventricular free walls (n=).
METHODS
Recording of single cell transmembrane potentials was performed and constructed action potential duration restitution (APDR) curve by plotting APD 90%(APD90) versus preceding diastolic interval (DI).
RESULTS
All isolated tissues fibrillated spontaneously. In this preparation, stable VF could persist over a 4-hour period if it was allowed to continue undisturbed (n=). Gliburide (1-5 uM) increased DI without significant changes in APD90 during VF, resulting in more regularization of VF. Higher concentration (10-20 uM) increased both APD90 and DI, and converted to monomorphic ventricular tachycardia (MVT) through the transitional period characterized by APD alternans. PCO400 (1-2.5 uM) caused a significant shortening of APD during MVT and a period of APD alternans became more evident before conversion from MVT to VF. Gliburide eliminated profibrillatory effect of PCO400. This antifibrillatory action of gliburide was accompanied by gradual decrease in the maximum slope of APDR curve during VF.
CONCLUSION
KATP channel blockade causes a transition from VF to MVT via lengthening of DI and APD alternans, concomitantly with a reduction of the slope of APD restitution curve.

MeSH Terms

Action Potentials
Membrane Potentials
Potassium Channels
Swine
Tachycardia, Ventricular
Ventricular Fibrillation*
Potassium Channels