The influence of verapamil and its isomers on vulnerability to ventricular fibrillation during acute myocardial ischemia and adrenergic stimulation in isolated rat heart

1986 ◽  
Vol 18 (6) ◽  
pp. 645-649 ◽  
Author(s):  
F THANDROYEN ◽  
L HIGGINSON ◽  
L OPIE ◽  
E YON
1993 ◽  
Vol 264 (3) ◽  
pp. H783-H790 ◽  
Author(s):  
C. Ibuki ◽  
D. J. Hearse ◽  
M. Avkiran

Transient (2 min) acidic (pH 6.6) reperfusion with low [HCO3-] solution suppresses reperfusion-induced ventricular fibrillation (VF) in the isolated rat heart. Using this preparation, we tested whether the effect was mediated by the high [H+] or the low [HCO3-] of perfusate. Left and right coronary beds were independently perfused with HCO3(-)-containing (25.0 mmol/l) solution at pH 7.4. Regional ischemia was then induced by stopping flow to the left coronary bed for 10 min. Hearts were subsequently assigned to four groups (n = 12 hearts/group), and the left coronary bed was reperfused with either HCO3(-)-containing (25.0 or 4.0 mmol/l) or HCO3(-)-free (5.0 mmol/l HEPES) solution, at pH 7.4 throughout (control reperfusion) or at pH 6.6 for the first 2 min and at pH 7.4 from 2 to 5 min (acidic reperfusion). Regardless of the buffer, controls exhibited a high (92 and 100%) incidence of VF; this was reduced to 42% in both of the acidic reperfusion groups (P < 0.05). There were no intergroup differences in heart rate, coronary flow, or size of ischemic zone. Thus high [H+], rather than low [HCO3-], appears to mediate the antifibrillatory effect of transient acidic reperfusion.


1996 ◽  
Vol 163-164 (1) ◽  
pp. 131-136 ◽  
Author(s):  
Valeri I. Kapelko ◽  
Vladimir L. Lakomkin ◽  
Olga V. Korchazhkina ◽  
Oleg I. Pisarenko

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