Reperfusion-induced arrhythmias in the isolated rabbit heart: characterization of the influence of the duration of regional ischemia and the extracellular potassium concentration.

摘要: The systematic investigation of the genesis and control arrhythmias during ischemia reperfusion requires a reproducible preparation in which can be induced with relative ease. requirements for appropriate statistical analysis often that large numbers animals studied hence cost becomes an important factor. rat offers many advantages but is criticized on basis its atypical action potential need exists alternative small animal model. guinea-pig, because highly collateralized coronary circulation, cannot used induction regional rabbit dismissed grounds it has low incidence arrhythmias. In present study we have shown if perfusion conditions (duration extracellular potassium concentrations) are appropriately selected then heart exhibits high susceptibility to reperfusion-induced Hearts ( n =10 each group) were subjected 20 min by artery ligation, concentration perfusate being 2.50, 2.75, 3.00, 3.25, 3.50 or 4.38 m . A bell-shaped relationship was demonstrated optimum at 3.00 where 60% hearts exhibited ventricular fibrillation 80% tachycardia. With concentrations above there progressive decline (only one out ten fibrillated when ). below also reduction fibrillation. Using optimally arrhythmogenic potassium, 10, 15, 20, 25, 30 40 followed 5 reperfusion. time-susceptibility curve obtained such increasing durations from Beyond this (at fibrillation) Heart rate flow no consistent significant either duration ischemia. Studies time onset showed 90% initiated within first 60 s variable. conclusion, under provides good model arrhythmias, here demonstrate relationships between concentration, ischemic duration.