Subepicardial transmembrane potentials were recorded from intact pig hearts to observe the changes induced by acute ischemia. Ischemia shortened action potential duration, and decreased its amplitude, upstroke velocity, and resting potential. The cells were unresponsive after 12 to 15 minutes of coronary artery occlusion, yet near normal action potentials could be restored by flushing the occluded artery with saline as late as 40 minutes after occlusion. The unipolar extracellular electrogram reflected unresponsiveness by a monophasic potential. Local refractory periods initially shortened by up to 100 msec. Later, postrepolarization refractoriness occurred and refractory periods lengthened often in excess of basic cycle length, thus resulting in 2:1 responses. The onset of early ventricular arrhythmias often coincided with a period of alternation and 2:1 responses, especially when these got out of phase in different regions. Reperfusion frequently led to ventricular fibrillation, and was associated with marked inhomogeneity in cellular responses. Re-entry within ischemic myocardium was the most likely mechanism for arrhythmias.
Circus movement in rabbit atrial muscle as a mechanism of tachycardia. II. The role of nonuniform recovery of excitability in the occurrence of unidirectional block, as studied with multiple microelectrodes
Electroide cather recording during malignant ventricular arrythmia following experimental acute myocardial ischemia. Evidence for re-entry due to conduction delay and block in ischemic myocardium
Slow ventricular activation in acute myocardial infarction. A source of re-entrant premature ventricular contractions
Characterization and localization of ventricular arrhythmias resulting from myocardial ischemia and infarction
Pathophysiology of tachycardia- and bradycardia-dependent block in the canine proximal His-Purkinje system after acute myocardial ischemia
Slow conduction and reentry in the ventricular conducting system. II. Single and sustained circus movement in networks of canine and bovine Purkinje fibers
Slow conduction and reentry in the ventricular conducting system. I. Return extrasystole in canine Purkinje fibers
Excitatory factors in ventricular tachycardia resulting from myocardial ischemia; potassium a major excitant
The effect of complete ischemia on the intracellular electrical activity of the whole mammalian heart
The electrocardiogram in normal and some abnormal conditions; in revived human fetal heart and in acute and chronic coronary occlusion
Myocardial ischemia. Nature of ischemic electrocardiographic patterns in the mammalian ventricles as determined by intracellular electrographic and metabolic changes
Antiischemic effect of trimetazidine: enzymatic and electric response in a model of in-vitro myocardial ischemia
An experimental model of the production of early after depolarizations by injury current from an ischemic region
Electrophysiological effects of diltiazem, nifedipine and Ni2+ on the subepicardial muscle cells of canine heart under the condition of combined hypoxia, hyperkalemia and acidosis
Three-dimensional analysis of regional mechanical function, blood flow and electrophysiological parameters during early myocardial ischemia in dogs
Conduction of the impulse in the ischemic myocardium--implications for malignant ventricular arrhythmias
Effects of L-propionylcarnitine on electrical and mechanical alterations induced by amphiphilic lipids in isolated guinea pig ventricular muscle
Relationship between hemodynamics and cardiac metabolism in the reperfusion period following hypothermic global ischemia
Ventricular tachycardia in the infarcted, Langendorff-perfused human heart: role of the arrangement of surviving cardiac fibers
Direct effect of dobutamine on action potential duration in ischemic compared with normal areas in the human ventricle
Dispersion of monophasic action potential duration: demonstrable in humans after premature ventricular extrastimulation but not in steady state
T-wave alterations at the onset of wall motion abnormalities during dobutamine echocardiographic stress test
Myocardial viability assessment by endocardial electroanatomic mapping: comparison with metabolic imaging and functional recovery after coronary revascularization
A new single catheter technique for simultaneous measurement of action potential duration and refractory period in vivo
Distribution of local repolarization changes produced by efferent vagal stimulation in the canine ventricles
Cellular electrophysiologic changes and "arrhythmias" during experimental ischemia and reperfusion in isolated cat ventricular myocardium
Repeated 15-minute coronary occlusions in pigs increase occlusion arrhythmias but decrease reperfusion arrhythmias that are associated with extracellular hypokalemia
A model of myocardial ischemia for the simultaneous assessment of electrophysiological changes and arrhythmias in intact rabbits
Optical mapping technique applied to biventricular pacing: potential mechanisms of ventricular arrhythmias occurrence
Expression of skeletal muscle sodium channel (Nav1.4) or connexin32 prevents reperfusion arrhythmias in murine heart
Mechanistic investigation into the arrhythmogenic role of transmural heterogeneities in regional ischaemia phase 1A
Ischemia-induced action potential shortening is blunted by d-sotalol in a pig model of reversible myocardial ischemia
Magnesium--a profibrillatory or antifibrillatory drug depending on plasma concentration, heart rate and myocardial perfusion
Modification by hypoxia, hyperkalaemia and acidosis of the cardiac electrophysiological effects of a range of antiarrhythmic drugs
Cellular and pathophysiological mechanisms of ventricular arrhythmias in acute ischemia and infarction
Comparison of the effects of regional ischemia and hyperkalemia on the membrane action potentials of the in situ pig heart. Experimental Cardiology Group, University of North Carolina at Chapel Hill
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