Ventricular fibrillation is the most common mechanism of sudden unexpected cardiac death in persons with asymptomatic or symptomatic coronary artery disease. The electrophysiologic mechanisms reviewed in this article include: automaticity of pacemaker fibers, transformation of nonpacemaker into pacemaker fibers, "injury" currents and reentry. Some of the conditions facilitating ventricular fibrillation include bradycardia, long QT syndrome, electrocution, electrolyte imbalance, drugs, sympathetic stimulation and myocardial ischemia. Electrophysiologic studies during acute myocardial ischemia suggest that the earliest activity at the onset of arrhythmia may originate at the sites of the surviving Purkinje fibers or at the epicardial rim. Reentrant arrhythmias arising in ischemic myocardium are attributed to nonhomogeneous distribution of local hyperkalemia and acidosis.
Electrocardiographic antecedents of primary ventricular fibrillation. Value of the R-on-T phenomenon in myocardial infarction
The effects of psychological stress and vagal stimulation with morphine on vulnerability to ventricular fibrillation (VF) in the conscious dog
Basis for recurring ventricular fibrillation in the absence of coronary heart disease and its management
The effect of vagus nerve stimulation upon vulnerability of the canine ventricle: role of sympathetic-parasympathetic interactions
Transmembrane potential changes and ventricular fibrillation during repetitive myocardial ischaemia in the dog
Extracellular potassium activity changes in the canine myocardium after acute coronary occlusion and the influence of beta-blockade
Prophylaxis of ventricular fibrillation after acute experimental coronary occlusion by chronic beta-adrenoceptor blockade with atenolol
Mechanism and time course of S-T and T-Q segment changes during acute regional myocardial ischemia in the pig heart determined by extracellular and intracellular recordings
Early identification of patients developing late in-hospital ventricular fibrillation after discharge from the coronary care unit. A 5 1/2 year retrospective and prospective study of 1,897 patients
Ventricular refractoriness during acute myocardial ischaemia and its relationship to ventricular fibrillation
Sequential unipolar strength-interval curves and conduction times during myocardial ischemia and reperfusion in the dog
Disparate electrophysiological alterations accompanying dysrhythmia due to coronary occlusion and reperfusion in the cat
Ventricular fibrillation during programmed ventricular stimulation: incidence and clinical implications
Effects of extracellular potassium on ventricular automaticity and evidence for a pacemaker current in mammalian ventricular myocardium
The effects of heart rate, myocardial ischemia and vagal stimulation on the threshold for ventricular fibrillation
Re-entrant ventricular arrhythmias in the late myocardial infarction period. 1. Conduction characteristics in the infarction zone
The effect of acute coronary artery occlusion on subepicardial transmembrane potentials in the intact porcine heart
Influence of sympathetic tone on ventricular fibrillation threshold during experimental coronary occlusion
Modification of ventricular fibrillation latency following coronary artery occlusion in the conscious pig
Interaction of sequential stimuli applied during the relative refractory period in relation to determination of fibrillation threshold in the canine ventricle
Slow ventricular activation in acute myocardial infarction. A source of re-entrant premature ventricular contractions
Abnormal automaticity in canine Purkinje fibers focally subjected to low external concentrations of calcium
Effect of high concentrations of free fatty acids on the ventricular fibrillation threshold of normal dogs and dogs with acute myocardial infarction
The electrophysiologic time-course of acute myocardial ischemia and the effects of early coronary artery reperfusion
Distinctive time course of ventricular vulnerability to fibrillation during and after release of coronary ligation
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
Initiation of ventricular fibrillation outside hospital in patients with acute ischaemic heart disease
Myocardial concentration of norepinephrine and cyclic AMP in ventricular fibrillation during acute myocardial ischemia
Detailed analysis of 24 hour ambulatory electrocardiographic recordings during ventricular fibrillation or torsade de pointes
A fast Fourier transform analysis of coronary reperfusion-induced ventricular fibrillation and the modification by dibutyryl cyclic AMP in a cat model
A dual electrophysiologic test for atrial antireentry and ventricular antifibrillatory studies. Effects of bethanidine, procainamide, and WY-48986
Long-term outcome of patients with hypertrophic cardiomyopathy successfully resuscitated after cardiac arrest
Antiarrhythmic properties of specific inhibitors of sarcoplasmic reticulum calcium ATPase in the isolated perfused rat heart after coronary artery ligation
The 1998 European Resuscitation Council guidelines for adult advanced life support: A statement from the Working Group on Advanced Life Support, and approved by the executive committee
Cellular electrophysiologic changes and "arrhythmias" during experimental ischemia and reperfusion in isolated cat ventricular myocardium
Electrocardiographic identification of abnormal ventricular depolarization and repolarization in patients with idiopathic ventricular fibrillation
Autonomic boundary conditions for ventricular fibrillation and their implications for a novel defibrillation technique
Cell calcium in the pathophysiology of ventricular fibrillation and in the pathogenesis of postarrhythmic contractile dysfunction
Elevated baseline potassium level within reference range is associated with worse clinical outcomes in hospitalised patients
Electrophysiologic basis for T wave alternans as an index of vulnerability to ventricular fibrillation
Suppression of calcium-induced repolarization heterogeneity as a mechanism of nitroglycerin's antiarrhythmic action
Regression of left ventricular hypertrophy prevents ischemia-induced lethal arrhythmias. Beneficial effect of angiotensin II blockade
Monophasic action potentials in a patient with multiform ventricular tachycardia without QT prolongation
Potent antifibrillatory effect of combined blockade of calcium channels and 5-HT2 receptors with nexopamil during myocardial ischemia and reperfusion in dogs: comparison to diltiazem
Metabolic consequences and predictability of ventricular fibrillation in hypoxia. A 31P- and 23Na-nuclear magnetic resonance study of the isolated rat heart
Arrhythmias are abnormalities in heart rhythms, which can be either too fast or too slow. They can result from abnormalities of the initiation of an impulse or impulse conduction or a combination of both. Here is the latest research on arrhythmias.
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Cardiac Conduction System
The cardiac conduction system is a specialized tract of myocardial cells responsible for maintaining normal cardiac rhythm. Discover the latest research on the cardiac conduction system here.
Brain ischemia is a condition in which there is insufficient blood flow to the brain to meet metabolic demand. Discover the latest research on brain ischemia here.
Atrial fibrillation is a common arrhythmia that is associated with substantial morbidity and mortality, particularly due to stroke and thromboembolism. Here is the latest research.
Bradyarrhythmias are slow heart rates. Symptoms may include syncope, dizziness, fatigure, shortness of breath, and chest pains. Find the latest research on bradyarrhythmias here.