Arrhythmias during myocardial infarction: Mechanisms, significance, and therapy.

Mobile coronary care, continuous electrocardiographic monitoring, electrical defibrillation, and effective antiarrhythmic agents have each contributed to the major advances made in the detection, prevention, and treatment of arrhythmias during myocardial infarction. Ventricular ectopy within the first few minutes of acute myocardial infarction is still a major cause of death in patients with coronary artery disease, and future work, including education of at least selected members of the lay population in the techniques of cardiopulmonary resuscitation, will be necessary to significantly reduce the incidence of prehospital sudden death. For patients who survive the early minutes of infarction and receive medical attention, the short and long-term prognosis is now largely determined by the amount of myocardium which is permanently affected by the ischemic process. The influence of disturbance of heart rate and rhythm on the balance between myocardial oxygen supply and demand, on hemodynamic function of the heart, and on experimental infarct size has been recognized. Future work must therefore also confirm that prevention and early therapy of potentially deleterious arrhythmias will limit infarct size, improve the short-term prognosis of patients with myocardial infarction, and decrease the incidence of late sudden death.