title: Arrhythmias and left ventricular function after defibrillation during acute myocardial infarction in the intact dog.
abstract: The purpose of this study was to assess the recovery of the left ventricular pressure (PLV), and the incidence and type of arrhythmias after effective low-dose defibrillation (Imax = 18-70 A) in healthy hearts and in hearts with acute myocardial infarction (AMI) in the intact dog. In fifteen dogs 84 episodes of fibrillation-defibrillation were studied in the healthy heart and 53 episodes were studied in the acute phase of myocardial infarction 1/2 to 3 hours after occlusion of a part of the left anterior descending artery by a catheter technique. Time to recovery of PLV depended on duration of fibrillation (tF) and cumulative defibrillation current (I 1/2), and became critical at tF greater than 45 seconds and I 1/2 greater than 45 A. Total duration of arrhythmias due to defibrillation increased with increasing tF and I 1/2. Arrhythmias which have a relative greater chance of resulting in refibrillation or which may seriously decrease the cardiac output occurred more often with I 1/2 greater than 55 A (p less than 0.001), when 50% of episodes were followed by these arrhythmias. No differences were found in responses between the healthy heart and the heart with AMI.
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology*; D001794:Blood Pressure; D004285:Dogs; D004554:Electric Countershock / Q000009:adverse effects*; D004562:Electrocardiography; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006336:Heart Massage; D006352:Heart Ventricles / Q000503:physiopathology*; D007773:Lactates / Q000097:blood; D009203:Myocardial Infarction / Q000097:blood / Q000503:physiopathology*; D013599:Systole; D013997:Time Factors
chemical_list: D005230:Fatty Acids, Nonesterified; D007773:Lactates