We studied the relation between [K+], and the electrophysiologic changes during a "Harris two-stage ligation," which is an occlusion of a coronary artery, preceded by a 30-minute period of 50% reduction of flow through the artery. This two-stage ligation has been reported to be antiarrhythmic. Local direct current electrograms and [K'], signals from up to 48 intramural sites were simultaneously...

BACKGROUND Previous work on endothelial dysfunction in post-MI heart failure has shown conflicting results. AIM To analyze gender related alterations in NO-, PGI(2)- and EDHF-dependent endothelial function in the thoracic aorta 7 and 42 days after myocardial infarction (MI). METHODS AND RESULTS MI was induced by coronary artery ligation in female and male Sprague-Dawley rats. There was no g...

The influence of acute myocardial ischemia and changes in ventricular dimensions on endocardial and epicardial electrograms were evaluated in 17 anesthetized open-chest dogs before and after left ventricular volume expansion and before and after coronary artery ligation. In eight dogs, regional myocardial blood flow was determined by the labeled microsphere technique. Endocardial QRS (endo-QRS)...

RATIONALE Coronary artery fistula (CAF) is characterized by an abnormal communication of a coronary artery with a cardiac chamber or a great vessel bypassing the capillary bed. Surgical closure of large or symptomatic CAF is the gold standard treatment. However the previously closed CAF still has the possibility to reopen. Superior vena cava syndrome (SVCS) is defined as a condition that occurs...

The importance of two arrhythmogenic mechanisms, ventricular reentry and automaticity, was assessed after coronary ligation in 35 cats. Automaticity was estimated by the frequency of ventricular escape beats after intravenous acetylcholine, and reentry was estimated by the number of repetitive beats induced by premature ventricular stimuli. Increased automaticity only was present after coronary...

• Hyperbaric oxygenation has been reported to be beneficial in a variety of conditions characterized by ischemia. The rationale for its use in acute myocardial infarction, as in other ischemic conditions, depends on the fact that the amount of physically dissolved oxygen in the capillaries, and hence potentially available for the tissues, is directly related to its partial pressure in the capil...

BACKGROUND Reperfusion injury (RI) has an important impact on the clinical prognosis for patients with acute myocardial injury who had their coronary blood flow reestablished. However, no studies to date have investigated the timeframe of coronary occlusion and reperfusion effects on RI. METHODS A total of 100 rats were divided into 4 groups based on the coronary ligation period: 30, 60, 120,...

Coronary occlusion in the dog results in irreversible myocardial cell injury which develops first in subendocardial areas of severe ischemica and subsequently spreads into mid and subepicardial areas of moderate ischemia. The effect of propranolol on this progression of ischemic injury was evaluated. Three groups of dogs were studied: 1) untreated, 2) treated with propranolol before and through...